Download Defining the “Ideal Construction Methods and Conditions”

Defining the “Ideal Construction Methods and Conditions” (I.C.M.C.) in Srby, Czech Republic,
Temperate to Continental European climate, for integrated environmental respect and optimized
energie consumption in residential buildings.
Thomas Austerveil
EnoncéThéoriqueJanvier2009
I would like to thank Dominique and Pierre Chuard, Antoine Amiard, Michel Corbe, Jiri Krol, Manuel Barthassat, Sebastien Luzelschwab, Pierre Jaboyedoff,
but also my parents Viviane & Jean-Jacques Austerveil and my beloved Anna Maria Trauttmansdorff
Contents
I. Preambule.
II.Introduction to climates.
a. World climates
b. Macroclimate
c. Mesoclimate
d. Microclimate
III. Focusing on a site (Srby, Czech Republic).
a. Locating the area
b. Understanding the context
c. Detailed review of specific climate conditions
d. Tracking the sun and its influences
IV. Strategies, from lessons learned based on climatic
conditions to solutions adopted.
V. Testing our solution in TRNSYS for first evaluation of
consumption.
VI. Conclusion.
Glossary.
Bibliography.
I. PREAMBULE Making a building is creating a system linked to its surrounding environment, and subject to a range of interactions affected by seasonal and daily changes in climate and by the varying requirements of occupants in time and in space. Some twentieth century buildings seek to deny these inevitable interactions and counteract them with expensive heating, cooling and lighting equipment. A more climate‐sensitive approach is proposed here which recognizes and responds to seasonal and daily changes in the environment for the wellbeing and comfort of the occupants. The relationship between people, their living place and the environment is re‐examined and resolved in an architecture which permits a dynamic interaction to occur. In recent years these issues have most frequently been addressed in the design process after the building form has been fixed, and we have become used to thinking of heating, cooling and lighting devices as add‐on equipment to be sized and placed in more or less completed buildings. While this may be a pragmatic or convenient approach, it diminishes the opportunity to design, at a more holistic level, buildings which can respond to the environment by virtue of their form and the intelligent use of materials with minimal reliance on machinery. Rediscovery of this design skill adds a dimension to the design process which offers sound parameters as generators of architectural form. To achieve this calls for a knowledge of climate and an awareness of the available technologies which can be employed in building, combined with an understanding of what constitutes comfort and discomfort and how these conditions can be affected by changes in climate. These issues are relevant to all buildings and locations whether the predominant need is for heating, cooling or daylighting. Initial design decisions will focus on the location of the building, its basic form, the arrangement of the spaces, the type of construction and the quality of the environment to be provided, resulting in an architectural response of high quality which is in harmony with its environment. In most situations it is necessary to provide some additional heating or cooling at certain times. Similarly, daylighting cannot meet all lighting requirements and therefore these auxiliary inputs and their control must be addressed once the contributions by natural means and the patterns of use are known. The design and construction of a building which takes optimal advantage of its environment need not impose any significant extra cost, and compared to more highly‐serviced buildings it may be significantly cheaper to run. There are two major strategies, depending on the regional climate and the predominant need for heating or cooling: • in cold weather ‐ maximize 'free' heat gains, create good heat distribution and suitable storage within the building and reduce heat losses while allowing for sufficient ventilation; • in warm weather ‐ minimize heat gains, avoid overheating and optimize cool air ventilation and other forms of natural cooling. To the above must be added a daylighting strategy. The availability of daylight is influenced by latitude and climate. The use of natural light to replace electrical light is particularly important in large buildings with a low surface‐to‐
volume ratio, where unwanted internal heat gains caused by artificial lighting can be considerable and often may require the use of mechanical air‐conditioning. Information on climate may be considered on three levels: macroclimate, mesoclimate, and microclimate. Macroclimatic data are gathered at meteorological stations and describe the general climate of a region, giving details of sunshine, wind, humidity, precipitation and temperature etc. Mesoclimatic data, although sometimes more difficult to obtain, relate to the modification of the macroclimate or general climate by established topographical characteristics of the locality such as valleys, mountains or large bodies of water and the nature of large‐scale vegetation, other ground cover, or by the occurrence of seasonal cold or warm winds. At the microclimate level we can consider the human effect on the environment and how this modifies conditions close to buildings. For example, planted vegetation and neighbouring buildings influence a site's exposure to the sun and wind. Water and vegetation affect humidity and city planning modifies wind direction, intensity and air temperature. All buildings have a primary function to enclose space to provide an internal environment suitable for habitation. This in turn provides an opportunity to create sheltered, comfortable spaces around the building which can have a significant amenity value at certain times of the year, and these external spaces can have a beneficial effect on the internal environment of the building by minimizing the need for artificial heating or cooling. The configuration of the building and the arrangement of spaces according to function becomes important as does the selection of systems or devices to control the natural heating or cooling of the building. In essence then, in cold periods the need is to collect and store heat energy for distribution when and where there is a need; for example, at night or to north facing rooms. Insulation is also required to allow heat to be retained. In warm periods the need is to avoid overheating from direct solar radiation or unwanted internal heat gains from appliances or people, and to dissipate heat by natural ventilation or other means of natural cooling. The use of south facing glazing, particularly in the form of a conservatory or attached sunspace as it is sometimes called, can in addition to the amenity value it provides, act as both a collector of heat and as a 'buffer zone' which can insulate part of the building when there is no heat from the sun. This dual role can be compared with the 'north facing buffer zone' which acts solely as a protection against heat loss. Once captured, heat may be stored within the structure of the building making use of the thermal inertia of heavy mass elements such as walls or floors without causing any overheating, and may be distributed throughout the building when needed. The design of insulation, which may be movable, can play an important role in retaining heat and controlling its storage and distribution. Fixed or movable devices may be used to prevent overheating from direct solar radiation. Again, the thermal inertia of the building structure may be used to reduce overheating and regulate internal temperatures. Unwanted heat from appliances or occupants may need to be controlled and heat dissipated by ventilation or other forms of natural cooling. Good daylighting design will optimize the collection of natural light, ensuring its distribution about the building to provide lighting levels appropriate to each activity while avoiding visual discomfort associated with high contrast or glare. The contribution which daylight can make to energy saving, visual comfort and the quality of the thermal living or working environment is relevant in all climates, whether the predominant need is for heating or cooling. ‐ The design of an isolated building and its immediate environment, where it is unaffected by neighbouring buildings, is one matter. However, more often, one must consider the negative and positive aspects of building in urban locations. Clusters of buildings create their own microclimates through shading, shelter, wind deflection, and the emission of heat. Depending on the climate, some of these aspects may be turned to advantage while others may have to be minimized. The interactions between buildings are by their nature very complex and while some design tools and guidelines exist to help the designer to understand the phenomena involved and predict how the building will perform, the development of more elaborate, often computer‐based tools continues. In order to provide conditions of thermal comfort a knowledge of the range of people's comfort tolerances is needed. Thermal comfort is affected by such factors as temperature, humidity, airflow (draughts), the level of physical activity, the amount of clothing being worn and even the weight of the individual concerned. Comfort is to some extent subjective and consequently a capacity for the individual to have some control over his or her environment is desirable. The section on Comfort characterizes the range of comfort conditions while the section on Behaviour gives pointers to the way people respond in buildings and how occupant behaviour may affect the building's performance. This essay attempts to demonstrate the benefits of an approach to the design of buildings and their immediate surroundings which takes advantage of natural phenomena instead of fighting the influences of nature with expensive and often environmentally‐destructive heating, cooling or lighting equipment and the energy they consume. The overall goals to which the essay is directed are improved thermal and visual comfort in more environmentally‐benign buildings, and the synthesis of these objectives in good architectural design. What is proposed is a fundamentally more thorough approach to building design which, while adopting additional performance parameters, offers the possibility of exciting new architectural design opportunities. Our goal here will be to prove that there is the possibility of achieving a residential building very low in energy requirements, even in the tough climatic conditions of the fringe between temperate and continental European climate. II.Introduction to climates. Understaning our Climate. Climate is the weather of a place averaged over a length of time. The earth's climate varies from place to place, creating a variety of environments. Thus, in various parts of the earth, we find deserts; tropical rain forests; tundras (frozen, treeless plains); conifer forests, which consist of cone‐bearing trees and bushes; prairies; and coverings of glacial ice. Climate also changes with time. For example, a thousand years ago, northern latitudes were milder than they are today. The warmer climate enabled Vikings from Iceland to settle on the southern coast of Greenland. But the colder climate that developed over the following centuries wiped out the settlements. One major environmental concern is that human activity may be changing the global climate. The burning of fossil fuels‐‐coal, oil, and natural gas‐‐to power motor vehicles, heat buildings, generate electric energy, and perform various industrial tasks is increasing the amount of carbon dioxide gas released into the atmosphere. Fossil fuels contain carbon, and burning them produces carbon dioxide. This gas slows the escape of heat released by the earth into space. Thus, an increase in atmospheric carbon dioxide may cause global warming‐‐a rise in the temperature of the air next to the earth's surface. Global warming could change rainfall patterns, leading to shifts in plant and animal populations. It could also melt enough polar ice to raise the sea level, and it could increase the frequency and severity of tropical storms. Climates vary from place to place because of five main factors: (1) latitude (distance from the equator), (2) altitude (height above sea level), (3) topography (surface features), (4) distance from oceans and large lakes, and (5) the circulation of the atmosphere. The Role of Latitude The sun continually sends electromagnetic radiation into space. Most of the radiation is visible light, and it also includes infrared (heat) rays and ultraviolet rays. About 30 percent of the radiation that reaches the earth's atmosphere is reflected back into space, mostly by clouds. The remaining 70 percent is absorbed by the atmosphere and the earth's surface, heating them. The intensity of the solar radiation reaching the atmosphere decreases with increasing latitude. The intensity depends on how high in the sky the sun climbs. The closer a place is to the equator, the higher the climb. At latitudes between 231/2 degrees north and 231/2 degrees south, the sun is directly overhead at noon twice a year. In these cases, the sun's rays shine directly down toward the surface. The radiation that reaches the atmosphere is therefore at its most intense. In all other cases, the rays arrive at an angle to the surface and are therefore less intense. The closer a place is to the poles, the smaller the angle and therefore the less intense the radiation. Due to decreases in the intensity of radiation, average temperatures decline from the equator to the poles. Seasonal changes in solar radiation and the number of hours of sunlight also vary with latitude. In tropical latitudes (those near the equator), there is little difference in the amount of solar heating between summer and winter. Average monthly temperatures therefore do not change much during the year. In middle latitudes, from the Tropic of Cancer to the Arctic Circle and from the Tropic of Capricorn to the Antarctic Circle, solar heating is considerably greater in summer than in winter. In these latitudes, summers are therefore warmer than winters. In high latitudes, north of the Arctic Circle and south of the Antarctic Circle, the sun never rises during large portions of the year. Therefore, the contrast in solar heating between summer and winter is extreme. Summers are cool to mild, and winters are bitterly cold. Terrain and Climate The higher a place is, the colder it is. Air temperature drops an average of about 6.5 Celsius degrees per 1,000 meters. The temperature of the air determines how much precipitation falls as snow, rather than rain. Even in the tropics, it is not unusual for mountaintops to be snow‐covered. The surface features of the earth influence the development of clouds and precipitation. As humid air sweeps up the slopes of a mountain range, the air cools, and so clouds form. Eventually, rain or snow falls from the clouds. Some of the rainiest places on earth are on windward slopes, those facing the wind. As winds blow down the opposite slopes, known as the leeward slopes, the air warms, and clouds thin out or vanish. Leeward slopes of mountain ranges are therefore dry. In addition, a rain shadow (dry area) may stretch hundreds of kilometers downwind of a mountain range. Oceans and large lakes make the air temperature less extreme in places downwind of them. An ocean or lake surface warms up and cools down more slowly than a land surface. Thus, between summer and winter, the temperature of the water varies less than the temperature of the land. The temperature of the water strongly influences the temperature of the air above it. Therefore, air temperatures over the ocean or a large lake also vary less than air temperatures over land. As a result, places that are immediately downwind of the water have milder winters and cooler summers than places at the same latitude but well inland. San Francisco and St. Louis, for example, are at about the same latitude and therefore receive about the same amount of solar radiation during the year. But San Francisco is immediately downwind of the Pacific Ocean, and St. Louis is well inland. Consequently, San Francisco has milder winters and cooler summers. The Influence of Wind Atmospheric circulation influences climate by producing winds that distribute heat and moisture. Six belts of wind encircle the earth: (1) trade winds that blow between 30 degrees north latitude and the equator, (2) trade winds that blow between the equator and 30 degrees south latitude, (3) westerlies (winds from the west) that blow between 30 degrees and 60 degrees north of the equator, (4) westerlies blowing between 30 degrees and 60 degrees south of the equator, (5) polar winds north of 60 degrees north latitude, and (6) polar winds south of 60 degrees south latitude. Trade winds north of the equator blow from the northeast. South of the equator, they blow from the southeast. The trade winds of the two hemispheres meet near the equator, causing air to rise. As the rising air cools, clouds and rain develop. The resulting band of cloudy and rainy weather near the equator is called the doldrums. Westerlies blow from the southwest in the Northern Hemisphere and from the northwest in the Southern Hemisphere. Westerlies steer storms from west to east across middle latitudes. Westerlies and trade winds blow away from the 30 degrees latitude belt. Over broad regions centered at 30 degrees latitude, surface winds are light or calm. Air slowly descends to replace the air that blows away. Descending air warms and is dry. The tropical deserts, such as the Sahara of Africa and the Sonoran of Mexico, occur under these regions of descending air. Polar winds blow from the northeast in the Arctic and from the southeast in the Antarctic. In the Northern Hemisphere, the boundary between the cold polar easterly winds and the mild westerly winds is known as the polar front. A front is a narrow zone of transition, usually between a mass of cold air and a mass of warm air. Where the air masses overlap, storms can develop and move along the polar front, bringing cloudy weather, rain, or snow. As the seasons change, the global wind belts shift north and south. In the spring, they move toward the poles. In the fall, they shift toward the equator. These shifts help explain why some areas have distinct rainy seasons and dry seasons. Parts of Central America, North Africa, India, and Southeast Asia have wet summers and dry winters. Southern California and the Mediterranean coast have dry summers and wet winters. a. World Climates The earth's surface is a patchwork of climate zones. Climatologists (scientists who study the climate) have organized similar types of climates into groups. This article uses a modified version of a classification system introduced in 1918 by Wladimir Koppen, a German climatologist. Koppen based his system on a region's vegetation, average monthly and annual temperature, and average monthly and annual precipitation. The modified version specifies 12 climate groups: (1) tropical wet, (2) tropical wet and dry, (3) semiarid, (4) desert, (5) subtropical dry summer, (6) humid subtropical, (7) humid oceanic, (8) humid continental, (9) subarctic, (10) tundra, (11) icecap, and (12) highland. Warm Climates Tropical wet climates Tropical wet climates are hot and muggy the year around. They support dense tropical rain forests. Rainfall is heavy and occurs in frequent showers and thunderstorms throughout the year. Average annual rainfall varies from about 175 to 250 centimeters. Temperatures are high, and they change little during the year. The coolest month has an average temperature no lower than 18 degrees C. The temperature difference between day and night is greater than the temperature difference between summer and winter. Frost and freezing temperatures do not occur. Plants grow all year. Tropical wet and dry climates Tropical wet and dry climates occur in areas next to regions that have tropical wet climates. Temperatures in tropical wet and dry climates are similar to those in tropical wet climates, where they remain high throughout the year. The main difference between the two climates lies in their rainfall. In tropical wet and dry climates, winters are dry, and summers are wet. Generally, the length of the rainy season and the average rainfall decrease with increasing latitude. Not enough rain falls in tropical wet and dry climates to support rain forests. Instead, they support savannas‐‐grasslands with scattered trees. Semiarid and desert climates Semiarid and desert climates occur in regions with little precipitation. Desert climates are drier than semiarid climates. Semiarid climates, also called steppe climates, usually border desert climates. In both climate groups, the temperature change between day and night is considerable. One reason for the wide swings in temperature is that the the skies are clear and the air is dry. Clouds would reflect much of the sun's intense radiation during the day, slowing the rate of heating of the air near the surface. At night, clouds and water vapor would absorb much of the earth's radiation‐‐most of which consists of infrared rays‐‐slowing the rate of cooling. Semiarid and desert climates occur over a greater land area than any other climate grouping. They occur in both tropical and middle latitudes. They cover broad east‐west bands near 30 degrees north and south latitude. Middle latitude semiarid and desert climates are in the rain shadows of mountain ranges. Winds that descend the leeward slopes of these ranges are warm and dry. Middle latitude semiarid areas and deserts differ from their tropical counterparts mainly in their seasonal temperature changes. Winters are much colder in middle latitude semiarid areas and deserts. Subtropical dry summer climates Subtropical dry summer climates feature warm to hot, dry summers and mild, rainy winters. These climates, sometimes called Mediterranean climates, occur on the west side of continents roughly between 30 degrees and 45 degrees latitude. The closer to the coast the area is, the more moderate the temperatures and the less the contrast between summer and winter temperatures. Humid subtropical climates Humid subtropical climates are characterized by warm to hot summers and cool winters. Rainfall is distributed fairly evenly throughout the year. Winter rainfall‐‐and sometimes snowfall‐‐is associated with large storm systems that the westerlies steer from west to east. Most summer rainfall occurs during thunderstorms and an occasional tropical storm or hurricane. Humid subtropical climates lie on the southeast side of continents, roughly between 25 degrees and 40 degrees latitude. Humid oceanic climates Humid oceanic climates are found only on the western sides of continents where prevailing winds blow from sea to land. The moderating influence of the ocean reduces the seasonal temperature contrast so that winters are cool to mild and summers are warm. Moderate precipitation occurs throughout the year. Low clouds, fog, and drizzle are common. Thunderstorms, cold waves, heat waves, and droughts are rare. Humid continental climates Humid continental climates feature mild to warm summers and cold winters. The temperature difference between the warmest and coldest months of the year in‐creases inland. The difference is as great as 25 to 35 Celsius degrees. Precipitation is distributed fairly evenly throughout the year, though many locations well inland have more precipitation in the summer. Snow is a major element in humid continental climates. Winter temperatures are so low that snowfall can be substantial and snow cover persistent. Snow cover has a chilling effect on climate. Snow strongly reflects solar radiation back into space, lowering daytime temperatures. Snow also efficiently sends out infrared radiation, lowering nighttime temperatures. Cool Climates Subarctic climates Subarctic climates have short, cool summers and long, bitterly cold winters. Freezes can occur even in midsummer. Most precipitation falls in the summer. Snow comes early in the fall and lasts on the ground into early summer. Tundra climates Tundra climates are dry, with a brief, chilly summer and a bitterly cold winter. Continuous permafrost (permanently frozen ground) lies under much of the treeless tundra regions. Icecap climates Icecap climates are the coldest on earth. Summer temperatures rarely rise above the freezing point. Temperatures are extremely low during the long, dark winter. Precipitation is meager and is almost always in the form of snow. Highland climates Highland climates occur in mountainous regions. A highland climate zone is composed of several areas whose climates are like those found in flat terrain. Because air temperature decreases with increasing elevation in the mountains, each climate area is restricted to a certain range of altitude. A mountain climber may encounter the same sequence of climates in several thousand meters of elevation as he or she would encounter traveling northward several thousand kilometers. For example, the climate at the base of a mountain might be humid subtropical, and the climate at the summit might be tundra. European Climates. Patterns of some permanence controlling air‐mass circulation are created by belts of air pressure over five areas. They are: the Icelandic low, over the North Atlantic; the Azores high, a high‐pressure ridge; the (winter) Mediterranean low; the Siberian high, centred over Central Asia in winter but extending westward; and the Asiatic low, a low‐pressure, summertime system over southwestern Asia. Given these pressure conditions, westerly winds prevail in northwestern Europe during the year, becoming especially strong in winter. The winter westerlies, often from the southwest, bring in warm tropical air; in summer, by contrast, they veer to the northwest and bring in cooler Arctic or subarctic air. In Mediterranean Europe the rain‐bearing westerlies chiefly affect the western areas, but only in winter. In winter the eastern Mediterranean basin experiences bitter easterly and northeasterly winds derived from the Siberian high, and their occasional projection westward explains unusually cold winters in western and central Europe, the exceptionally warm winters of which, on the other hand, result from the sustained flow of tropical maritime air masses. In summer the Azores high moves 5°–10° of latitude northward and extends farther eastward, preventing the entry of cyclonic storms into the resultantly dry Mediterranean region. The eastern basin, however, experiences the hot and dry north and northeast summer winds called etesian by the ancient Greeks. In summer, too, the Siberian high gives place to a low‐pressure system extending westward, so that westerly air masses can penetrate deeply through the continent, making summer a wet season. It is because of the interplay of so many different air masses that Europe experiences very changeable weather. Winters get sharply colder eastward, but summer temperatures relate fairly closely to latitude. Northwestern Europe, including Iceland, enjoys some amelioration because of warm Gulf Stream waters, which keep the Russian port of Murmansk open throughout the year. Climatic regions Four regional European climatic types can be loosely distinguished, each characterized by much local topographically related variation. Further, the great cities of Europe, because of the scale and grouping of their buildings, their industrial activities, and the layout of their roads, create distinct local climates—including a central “heat island” and pollution problems. Maritime climate Characterizing western areas heavily exposed to Atlantic air masses, the maritime type of climate—given the latitudinal stretch of these lands—exhibits sharp temperature ranges. Thus, the January and July annual averages of Reykjavík (Iceland) and Coruña (Spain) are, respectively, 32° F (0° C) and 53° F (12° C), and 50° F (10° C) and 64° F (18° C). Precipitation is always adequate—indeed, abundant on high ground—falling the year round. The greatest amount of precipitation occurs in autumn or early winter. Summers range from warm to hot depending on the latitude and altitude, and the weather is everywhere changeable. The maritime climate extends across Svalbard, Iceland, the Faeroes, Great Britain and Ireland, Norway, southern Sweden, western France, the Low Countries, northern Germany, and northwestern Spain. Central European (transitional) climate The central European, or transitional, type of climate results from the interaction of both maritime and continental air masses and is found at the core of Europe, south and east of the maritime type, west of the much larger continental type, and north of the Mediterranean type. This rugged region has colder winters, with substantial mountain snowfalls, and warmer summers, especially in the lowlands. Precipitation is adequate to abundant, with a summer maximum. The region embraces central Sweden, southern Finland, the Oslo Basin of Norway, eastern France, southwestern Germany, and much of central and southeastern Europe. The range between winter and summer temperatures increases eastward, while the rainfall can exceed 80 inches (2,000 millimetres) in the mountains, with snow often lying permanently around high peaks. The Danubian region has only modest rainfall (24 inches per year at Budapest), but the Dinaric Alps experience heavy cyclonic winter, as well as summer, rain. Continental climate The continental type of climate dominates a giant share of Europe, covering northern Ukraine, eastern Belarus, Russia, most of Finland, and northern Sweden. Winters—much colder and longer, with greater snow cover than in western Europe—are coldest in the northeast, and summers are hottest in the southeast; the January to July mean temperatures range from 50° to 70° F (10° to 21° C). Summer is the period of maximum rain, which is less abundant than in the west: Moscow’s annual average is 25 inches, while, in both the north and southeast of the East European Plain, precipitation reaches only between 10 and 20 inches annually. In parts of the south, the unreliability of rainfall combines with its relative scarcity to raise a serious aridity problem. Mediterranean climate The subtropical Mediterranean climate characterizes the coastlands of southern Europe, being modified inland (for example in the Meseta Central, the Apennines, and the North Italian Plain) in response to altitude and aspect. The main features of this climatic region are mild and wet winters, hot and dry summers, and clear skies, but marked regional variations occur between the lands of the western and the more southerly eastern basins of the Mediterranean; the former are affected more strongly by maritime‐air‐mass intrusions. Rainfall in southern Europe is markedly reduced in areas lying in the lee of rain‐bearing westerlies: Rome has an annual mean of 26 inches, but Athens has only 16 inches. The effects of climate The local and regional effects of climate on the weathering, erosion, and transport of rocks clearly contribute much to the European landscape, and the length and warmth of the growing season, the amount and seasonal range of rainfall, and the incidence of frost affect the distribution of vegetation. Wild vegetation in its turn provides different habitats for animal life. Climate is also an important factor in the making of soils, while modern European industry and urban life depend increasingly on water supplies, with rivers and lakes continuing to provide important commercial waterways in some areas. The winter freeze in northern and eastern Europe is another effect of climate, and the spring thaw, by creating floods, impedes transport and harasses farmers. The snow cover of the more continental regions is useful to people, however, for it stores water for the fields and provides snow for sled users. The Czech Republic as an example of complexity… The Czech Republic is a landlocked country located in moderate geographical latitudes in the Northern Hemisphere.The climate of the Czech Republic is mild but variable locally and throughout the year. The climate differs markedly among the various regions of the Czech Republic, depending on the height above sea level. Generally speaking, the higher you are, average temperatures may drop more and rainfall is more likely. Many other factors also play a role in this – the border mountain ranges, for example, significantly influence ground‐level air flow and rainfall. Various height levels of the sun during the year cause the changing of the seasons, differentiated from each other mainly by the development of temperatures and precipitation. Similarly to the whole moderate northern band, the beginning of the year in the Czech Republic is also characterized by a cold winter. After this comes spring, followed by a warm summer and chilly autumn. The alternation of the seasons has a marked effect, above all on vegetation. The weather at any given time may differ significantly from the long‐term average. This variability of the weather is caused mainly by the changeable location and magnitude of two main pressure centers: the Icelandic Low and the Azores High. Mainly during the warm middle of the year, it can generally be said that expansion of the high pressure projection into our territory causes warmer and drier temperatures, whereas the Icelandic Low manifests itself with a greater number of atmospheric fronts, which bring more clouds and precipitation. The climate of the Czech Republic can then be labeled as moderate, of course with great local diversity seen throughout the year. Further changeability then is up to the weather itself. Diversity of the Czech climate Some of the main climatological factors are the geographical latitude, height above sea level and distance from the ocean. Differences in geographical latitude are negligible in the Czech Republic; the northernmost point is only 2.5 degrees further north than the southernmost. The most important factor in the diversity of the Czech climate remains the varied topography, thanks to which the climate varies among individual regions of the country. The average air temperature is strongly dependent on the height above sea level. When the temperature on the highest mountain in the Czech Republic, Sněžka (1,602 meters), is only 0.4 °C, the lowlands of southeast Moravia can experience temperatures of almost 10 °C. The highest average air temperatures have also been recorded in Prague, where the effect of the city climate has a warming effect – the “heat island” phenomenon. The annual rainfall is also markedly dependent on the height above sea level. If we want to find the rainiest area in the Czech Republic, we would have to look to the highest mountain range with steep slopes facing northwest. The average total rainfall there is in excess of 1,200 millimeters. On the other hand, the driest region of the Czech Republic, apart from the lowest‐situated, southeast Moravia, is northwest Bohemia, which is shaded in this direction by the Krušné Mountains. Characteristics of the seasons December, January and February are counted as the winter months. The coldest of these is January, when even in the lowlands the average monthly temperature falls below 0 °C. If there is any precipitation in winter, it is usually snowfall in the mountains. In the lowlands it can alternately rain and snow. Snow coverage usually lasts for several months at higher altitudes above sea level, which attracts winter sports enthusiasts. Snow can remain for several days, even in the lowlands, although most winters it is rather “slushy.” During March, April and May, there is a sharp increase in temperatures. We can get an idea of the character of individual months from the following saying: “Březen ‐ za kamna vlezem, duben ‐ ještě tam budem, máj ‐ půjdeme v háj“ (“March – we get behind the stove, April – we’ll still be there, May – off we go to the garden”). Snow coverage usually disappears in the mid‐spring, even in the highest mountains of the Czech Republic, so even there the swift growth of vegetation so typical for spring can occur. Czech rivers are at their fullest in spring as a result of the melting snow. There are many Czech folk traditions connected with this period. If you love heat, the best time to visit the Czech Republic is July, when the average temperature is 20 °C warmer than in January. The hottest daily temperatures can be in excess of 30 °C. Days such as these can be pleasantly spent near the water, which truly heats to a suitable temperature for swimming in the second half of summer. Another way to escape the sultry summer heat is to take a trip to the mountains, where the average daily temperatures are just over 10 °C. The hottest months are also those with the most rainfall as the hot air brings the highest level of moisture to the Czech Republic. The first of the autumn months is August, which is still relatively hot and markedly drier than the preceding month. The period of good weather that usually comes in August is known as Indian Summer. The average daily temperatures usually fall once again below 10 °C around the start of October, which is when the leaves on the trees begin to change into a multitude of colors and fall to the ground: This is why the Czech word for November is derived from the words for falling leaves. The first light frosts can also occur at this time, announcing the nearness of the coming winter. TURNING THINGS AROUND AND MAKING USE OF OUR CLIMATIC CONDITIONS “In the beginner’s mind there are many possibilities, but in the expert’s there are few.” (Shunryu Suzuki) “Look at the almond tree in your front yard.” (Thich Nhat Hanh) From the viewpoint of human comfort and energy use, the climatic condition of a place can be divided broadly into negative and positive effects. In general, the aim of climate‐conscious architecture is to provide protection from the negative factors and take advantage of the positive ones in order to meet the comfort requirements of the inhabitants and secure an economical level of energy consumption. A year‐round analysis is required. Buildings have to perform appropriately in summer, winter and intermediate seasons. The latter are often characterized by great day‐to‐ day variability, demanding flexibility of operation. To allow the architect to analyse the climate at a particular site, the climatic factors need to be expressed quantitatively. The key factors are the position of the sun, the amount of solar energy, the air temperature, long wave radiation and wind condition. Humidity, best assessed as the water‐vapour pressure, is also an important factor in hot weather. The geometric range of the sun's position throughout any particular day determines the directly‐radiated surfaces. The range changes from season to season. The strength of the direct solar beam on a specific surface is described by its beam irradiance. This is the heat flow per unit area and is expressed in watts per square metre (W/m2). In Europe at low level sun, the beam irradiance seldom exceeds 900 W/m2. As well as the direct solar beam, building surfaces also receive diffused solar radiation scattered by the air and particles in the sky and reflected from clouds, ground, adjacent buildings, etc. If the solar energy reaching a surface is summed over a stated period of time, the irradiation is obtained. The outdoor air temperature describes the thermal ambience of a place. It can be measured using thermometers shaded by a well‐ventilated whitened meteorological screen mounted at a standard height. Air temperature is a major factor in determining thermal comfort. Knowledge of wind conditions makes it possible to assess the impact wind can have on ventilation and heat loss. Information on typical wind speeds and directions is needed to devise protection against adverse winds in winter. In summer, positive use of wind for natural cooling is important, especially in southern Europe. Wind speeds are very dependent on height above ground. Substantial deflections are caused by buildings. The humidity of the air exerts a strong influence on comfort in hot weather. High water vapour pressure makes it difficult for the body to evaporate sweat at adequate rates to stay cool. The available observed values of the above climatic factors are those measured at meteorological stations where the instruments are mounted under standardized conditions at standard heights above level, grass‐ covered ground. These measured values provide the macroclimate database for the area. Sometimes, access to more local data can help the architect to understand the conditions of the site more fully. The architect must always interpret the required climate data according to the place where he wants to build. He or she must consider the mesoclimate — the modifications which topography and vegetation make to the macroclimate of the region. He or she must also take into account the microclimate — the effect on the mesoclimate of what man does to the local environment. Wind flow is strongly affected by topography — for instance, by the shelter provided by hedgerows and trees, by the surface properties of features such as lakes or shrubs, and by the shape of the ground. Wind flow is also affected by nearby buildings: in towns, it can be highly perturbed. The temperature microclimate is influenced by the wind microclimate. It is also affected by the nature of the ground cover. For instance, dark pavements heat up in the sun whereas green grass produces a much cooler environment. The solar radiation climate at the site is affected by the presence of pollution. This chapter begins by explaining the main climatic features found in Europe's major climate zones. Information is then given about the changes which have to be applied to the general values to provide mesoclimate data for the local area. Finally, the last section of the chapter examines the microclimate experienced at sites due to man‐made modifications to the environment. Microclimate data can be estimated but it is desirable to complement this with direct measurement on site. It can be helpful for the architect to note the way in which the vernacular architecture and natural features handle or are affected by the local climate conditions. It can also be useful to collect information about the site from local inhabitants — although care should be taken that the latter do not exaggerate the frequency of extreme conditions ! DEFINING CRITICAL CONDITIONS DERIVED FROM THE DIFFERENT SCALES OF CLIMATES b. Macroclimate Macroclimate data, which is provided by standard meteorological stations, describes the general character of a region in terms of sunshine, cloud, temperature, wind, humidity and precipitation. An understanding of the climate is essential to the design of climate‐responsive buildings. CLIMATE CONDITIONS IN EUROPE Most of the European Community is located in a climatic region which is more or less temperate and is bounded by areas with strongly contrasting physical characteristics — the Atlantic Ocean to the west, the Arctic Sea to the north, a large continental land mass to the east and the Mediterranean Sea and North Africa deserts to the south. The winds coming from the west are usually relatively humid. When westerly flows from the Gulf Stream are present in winter, the warm humid air causes relatively mild, humid and cloudy weather. In summer, the westerly flows remain humid but the air is usually cool and fresh compared with the east winds. The westerly flows normally carry much less dust so that when the sun shines through gaps in the commonly‐occurring clouds the beam strength is relatively high. The diffuse radiation caused by reflection in clouds is often strong under broken cloud conditions. The north winds bring cold, dry air from the Arctic. In winter, the east winds (generated under the direct influence of the Siberian anticyclones) bring about the cold winters of Central Europe. The air then is cold but dry with fewer clouds (and therefore more solar radiation) than with westerly flows. In summer, the easterly continental air flows tend to be warm and dusty, reducing the strength of the solar beam. Winds in the southern and eastern areas of the Community are strongly influenced by the blocking effects of the Alps. While more detailed information can be obtained from maps which deal specifically with wind, solar radiation, temperature, humidity and precipitation, a combination of these provides a broad characterization of the climate in Europe: 1. Northern European Coastal zone: Cold winters with low solar radiation and short days, mild summers. 2. Mid European Coastal zone: Cool winters with low solar radiation, mild summers. 3. Continental zone: Cold winters with high solar radiation and longer days, hot summers 4. Southern and Mediterranean zone: Mild winters with high solar radiation and long days, hot summers. THE SUN AND IT'S POSITION The position of the sun in the sky, and hence the direction of the solar beam, is described by the solar altitude and solar azimuth angles. The solar altitude (7) is the angle between the line to the centre of the sun and the horizontal plane. When the sun is on the horizon, the solar altitude is 0 degrees. When the sun is directly overhead, it is 90 degrees. The azimuth (a) is the angle between true south and the point on the horizon directly below the sun. By convention, it is negative before noon and positive after noon. The altitude and azimuth angles vary from hour to hour and season to season. At the northern latitude summer solstice (21 June), the sun's rays make an angle of 23°27' to the equatorial plane. The beam is approximately perpendicular to the Tropic of Cancer (22°30'N). In the northern hemisphere, the day length reaches its maximum value then. North of latitude 23°27'N, the noon solar altitude is at its greatest value for the year. At the winter solstice (21 December), the sun's rays make an angle of ‐23°27' to the equatorial plane. The beam radiation is approximately perpendicular to the Tropic of Capricorn (20°30'S). In the northern hemisphere, the days are at their shortest and the noon solar altitudes have their lowest values. At the northern hemisphere spring and autumn equinoxes (21 March and 22 September), the sun's rays are perpendicular to the equator. The day and night lengths are almost equal everywhere in the world. The solar altitude and azimuth for the whole year, hour‐by‐hour, can be plotted on a solar chart. The altitude scale is shown on a series of concentric circles. The azimuth scale is set around the perimeter of the chart. The azimuth angle is read by setting a straight edge from the centre of the chart to the intersection of the required hour and date path lines and noting where it cuts the chart perimeter. Different charts are required for different latitudes. In Europe, the extreme values of the sun's position are as follows: • in the south of Europe (for example, in southern Greece) at latitude 36 N, the sun's path is 240 degrees wide at the summer solstice and the maximum solar altitude is 77 degrees. At the winter solstice, the sun's path is 120 degrees wide and the maximum solar altitude is 30 degrees. • in the north of Europe (for example, in Denmark or Scotland) at latitude 56 N, the sun's path is 270 degrees wide at the summer solstice and the maximum solar altitude is 58 degrees. At the winter solstice, the sun's path is 90 degrees wide and the maximum solar altitude is 11 degrees. THE SUN AND IT'S RADIATION The amount of solar radiation reaching the ground depends on the composition of the atmosphere and the path length of the beam. As the beam radiation passes through the atmosphere it is partly scattered by air molecules, dust particles and water droplets and partly absorbed by water vapour, ozone, carbon dioxide and other gases. Clouds, in particular, cause absorption and scattering. Over 60% of the radiation reaching horizontal surfaces at high latitudes in the European Community is diffuse, as a result of such scattering. The proportion of diffuse radiation is smaller in southern Europe. The longer the path length through the atmosphere and the greater the amount of water vapour and dust particles, the weaker the solar beam. The sum of the direct (or beam) and diffuse solar irradiation on a horizontal surface constitutes the globally available energy. The quantity of available energy due to solar radiation, sometimes called the energetic exposure, is a function of the irradiance. The solar irradiance is the amount of radiant energy from the sun falling on a square metre of surface at any instant. It is usually measured in Watts per square metre and, as indicated above, has two components, the beam component and the diffuse component. • The beam irradiance falling on a given surface (GO depends on the angle of incidence between the sun's rays and the normal (a line at 90°) to the surface. • The diffuse irradiance (Gd) is the sum of the diffuse irradiance received from the sky after being reflected from the clouds. To this can be added the diffuse irradiance reflected from the ground, the neighbouring landscape and adjacent buildings. The sum of the direct (beam) and diffuse irradiation on the surface is known as the global irradiance (G). Irradiance varies from moment to moment. It is dependent on geographical area, latitude, season, time of day and meteorological conditions. If the irradiance on a surface is integrated over a stated period of time, the irradiation is obtained. The commonly‐used period of integration is the day, so typically irradiation is given in Kilowatt hours (kWh) per square metre per day. In Europe, the value for the annual mean daily irradiation on a horizontal surface varies from 2.25 kWh per square metre in Scotland to 6 kWh per square metre per day in the Mediterranean area. Data for horizontal surfaces at meteorological stations throughout the Community can be found in Volume I of the Commission of the European Communities' European Solar Radiation Atlas. Inclined surfaces receive different amounts of daily irradiation to horizontal surfaces. Tilting a surface towards the mean position of the sun increases the daily irradiation. In addition, the colour of the ground influences the daily slope value because it affects the amount of radiation reflected from the ground onto the inclined surface. Maps of calculated irradiation data for inclined surfaces throughout the European Community are given in Volume II of the European Solar Radiation Atlas. In preparing the maps a ground albedo (the proportion of the incident solar radiation reflected from the ground) of 0.2 was assumed. TEMPERATURE At any instant, the air temperature at a site depends on two factors; incoming air flows driven by large‐scale weather systems, and local climatic energy inputs. The latter modify the temperature of the incoming air to a greater or lesser extent, according to its speed. When the wind speed is slow, site factors such as the heating of the ground by sunshine and night‐time cooling from outgoing long wave radiation exert a major influence on the air temperature close to the ground. With high wind speeds, the temperature of the incoming air mass is less affected by local factors. Local inputs of climatic energy have a significant effect on the daily air temperature swing close to the ground. As one moves further up from the ground, the impact of ground diurnal temperature variations rapidly decreases. Therefore, under most meteorological conditions, mean daily temperature decreases with distance from the ground. To achieve comparable measurements of temperatures at different sites, thermometers measuring air temperature are mounted at a standard height of about 1.2 m above the ground in a whitened, insulated and ventilated meteorological screen. These screens are normally set above short mown grass on level ground, well away from trees, buildings, walls and other obstructions. Temperatures measured closer to the ground will reveal a bigger range of daily variations. The typical mean temperature of the incoming air mass depends on its place of origin. Air from the polar regions is normally cold and dry. Air from the Atlantic Ocean is usually humid and is relatively warm in winter and relatively cool in summer. Air from the east is typically cold and dry in winter and relatively hot and turbid in summer. The hot, dry and dusty air from the Sahara sometimes impinges on southern Europe and, occasionally, even further north. In both summer and winter, directional temperature data for Hamburg can be regarded as representative of northern Europe. The ground of the site is heated by incoming solar radiation. It is cooled by convection, long wave radiation and evaporation of water. The evaporation of ground water through irradiated vegetation ‐ a process called evapotranspiration ‐ is particularly important for controlling air temperatures. The highest temperatures are found in hot sunny weather over dark surfaces with no vegetation cover. The heating effect of the ground on the air determines air temperatures at habitable levels. There is a daily temperature swing with maximum temperatures usually occurring in the afternoon and the lowest temperatures just after dawn. In overcast weather the daily temperature swing is usually small. Very close to the ground, the temperature of the air approaches that of the ground surface. This influence decreases with distance from the surface. In the middle of a still night, the external air temperature at the top of a tall building may remain substantially above that at the ground floor. At night, the surface temperature of the ground may fall below the air temperature because of emission of long wave radiation to the sky — a process which is greatest when there is no cloud. If the surface temperature falls below the dew point, then dew (or ice, if conditions are sufficiently cold) will form. Ground frosts are most likely to occur at low wind speeds. When the ground is heated strongly, warm air begins to rise in quite large parcels. This ascending warm air is cooled and, if it is humid enough, will form convective cumulus clouds. In fine weather, the amount of cloud tends to increase towards the afternoon. The circulation of air by convection also increases wind movement in the afternoon. This effect dies down again in the evening. WIND Winds or air movement in the earth's atmosphere are caused by pressure differences generated by complex climatic factors. Wind speed and direction are normally measured in meteorological networks at a height of 10 m. Where possible, sites are selected which are exposed in all directions. As substantial obstacles to air flow exist at ground level in towns, urban air movement is generally quite turbulent. For European regions north of the Alps, the prevailing winds are from the south‐west. In winter these winds are generally warm and bring rain. Southern winds are warm and dry. Northern, polar winds are cold. Northeastern winds in winter are cold and dry. Around the Alps and Pyrenees, cold winds blow from the summits to the warmer lowlands. Wind is a major design factor for architects. It affects comfort and influences rainfall. It modifies the heat exchange of a building envelope through convection and it causes infiltration of air into the building. HUMIDITY Air humidity may be described in four ways: • • • • dry and wet bulb temperature air temperature and relative humidity vapour pressure (in millibars) dew point. The vapour pressure is the most stable variable across the day. The relative humidity varies considerably, tending to be highest close to dawn when the air temperature is lowest, and decreasing as the air temperature rises. This is because the relative humidity is related to saturated vapour pressure, i.e, the amount of water the air can hold at any given temperature. The saturated vapour pressure increases strongly with rise in temperature. The fall in relative humidity in the middle of the day tends to be greatest on summer days but such days remain uncomfortable because the vapour pressure does not fall. In winter, monthly mean daily relative humidities are very high in western Europe. They tend to increase as one proceeds towards the Atlantic Coast. In summer, they are lower but still quite high due to the Atlantic influence. They fall with dry winds from the polar regions and dry winds from the desert areas south of the Mediterranean. When humid air is cooled to its dew point, the vapour will form dew, hoar frost, fog, rime ice or cloud droplets. The latter may coalesce to form rain, hail or snow. In areas with high humidity levels, transmission of solar radiation is reduced because it is absorbed by water vapour and scattered and absorbed by clouds. Very dry air, on the other hand, causes hot days and cold nights. In most parts of Europe, the humidity level is inside the comfort range for most of the year. Severe thermal discomfort only occurs when high vapour pressures combine with high temperatures to give hot, humid conditions or low humidity combines with high temperatures to produce hot, desiccating atmospheres. These conditions are most likely to be found near the Mediterranean Sea. c. Mesoclimate The climatic factors described in the preceding section on macroclimate are influenced by local conditions such as topography, vegetation and the nature of the area and its environs. SOLAR RADIATION Two factors have a major influence on the solar radiation received at a particular site: the turbidity of the atmosphere and the presence of geometric obstructions. TURBIDITY Turbidity consists of dust and suspended droplets of water, etc., which partly absorb and partly reflect (i.e. scatter) the solar radiation as it passes through the atmosphere. Turbidity in the general continental atmosphere of western Europe is highest in summer when the amount of dust is greatest and large amounts of water vapour can produce very hazy skies. In towns, pollutants from the concentration of cars, factories, heating systems, etc., absorb and scatter sunlight, weakening the direct solar beam but increasing the diffuse radiation on cloudless days. A dome of pollution can sometimes be seen above cities. In recent years, however, improvements in smoke control from factories and heating systems have lessened the turbidity difference between town and countryside. However, pollution from traffic has increased so that, overall pollution has become more widespread. The condition in towns is now at its worst in summer when sunlight acting on traffic exhausts produces some very unpleasant effects. Low‐level pollution by solid particles can be reduced by the presence of trees. The leaves act as a filter. Dust particles either cling to their surfaces or, having fallen on them, drop to the ground below. The air in the centre of an urban green space with plenty of trees is purer than the air near the perimeter. GEOMETRIC OBSTRUCTIONS Geometric obstructions can be classified into three general classes — those related to the topography of the area, vegetation on or near the site and nearby buildings. They all, to a greater or lesser extent, shade the site from the sun. The precise impact of the obstructions on the amount of solar radiation received can be assessed geometrically using solar charts of the type described in the section on macroclimate, coupled with some ancillary aids. TOPOGRAPHY The geometrical assessment has to take into account the three‐dimensional nature and seasonal effect of the surrounding terrain. Obstructions to the south tend to cause most overshadowing in winter because of the sun's low altitude. Valleys running east‐west therefore face the greatest risk of permanent overshadowing from the southerly slope in winter. In northern Europe it is best, where possible, to locate buildings high enough up the south slope to catch significant amounts of winter sun. VEGETATION The effect of deciduous vegetation also varies according to season. Overshadowing is diminished when the leaves fall in autumn. When the deciduous trees are in leaf, part of the incident sunlight diffuses through the leaves and the radiation is not blocked entirely. Conifers, on the other hand, block sunlight to a greater extent throughout the year. BUILDINGS Surrounding buildings have an effect on the amount of sunlight and diffuse radiation received at the site. Their impact on sunlight availability changes with season and it is necessary to bear this in mind in developing a site. Not only must the effect of existing construction be taken into account in carrying out the assessment but also the influence of likely future building developments. TEMPERATURE The temperature of the air at a site is influenced by topography, vegetation and the nature of the nearby ground surfaces. TOPOGRAPHY Topography influences air temperature because of its effect on orientation and tilt of the ground, wind exposure, night‐time cooling and flow of heated and cooling air. Ground surfaces oriented and tilted towards the sun are more strongly irradiated than other surfaces. When the sun is shining, favourably‐inclined surfaces become warmer compared with unfavourably oriented, untilted and/or overshadowed surfaces. In sunny weather, surfaces most exposed to wind will experience the smallest temperature rises: the wind will rapidly remove surface heat by forced convection, substantially reducing any potential warming. This effect can be considerable in, say, a hill site when the sun is in the south‐west and the wind in the north‐east. Under night‐time cooling conditions, if the air outside is hot its capacity for cooling the building surfaces will be reduced. The various flows of heated rising air and cooling sinking air will be affected by the structure of the terrain changing the temperature patterns. In a complex terrain this can produce a very wide range of microclimates. For instance, on sunny days, valleys are generally warmer than hilltops. At night, however, as the slopes cool the air in contact with them runs down into the valley to form pools of cool air at the bottom. Thus, at night sites on favourably‐oriented slopes may be warmer than those in the valley. VEGETATION In well‐wooded areas, the trees intercept 60% to 90% of the solar radiation causing a substantial reduction in the daytime increase of the surface temperature of the ground below. The air below foliage remains cooler than elsewhere. This produces a stable configuration of layers of cooler (heavier) air below warm (lighter) air masses round sunlit foliage. As a result, there is a reduced turbulence and air movements in the layers close to the ground. This daytime phenomenon may be permanent or seasonal depending on whether the trees are deciduous or evergreen. After dark, the foliage hinders the outgoing long wave radiation and reduces the nighttime temperature drop. Diurnal temperature differences are therefore smaller in woodlands than in open countryside. GROUND SURFACES The temperature of the air is influenced by the nature of surrounding surfaces which intercept the solar radiation. The colour of the ground affects the relative proportions of incident radiation which are absorbed and reflected; dark colours tend to produce high surface temperatures. Other ground surface properties also have an effect on air temperature. In considering this whole subject it is useful to categorize ground cover into three general types — vegetation‐covered areas, surfaces covered with dry materials such as concrete, brick, etc., and surfaces covered with water. Lawns and areas covered with low shrubs are examples of vegetation‐ covered areas where surface temperature cooling takes place by evaporation of the water transpired through the leaves. As the surfaces of the leaves do not heat up much in the sun this process reduces the air temperature above the vegetation throughout the day. It does, however, increase vapour pressure. Concrete, bricks, gravel, cobble stones and other materials with a high thermal inertia, when set in a layer over the underlying earth, are all examples of dry ground cover. The temperature rise of these surfaces depends on the surface colour. Heat is stored in the day and re‐emitted in the evening. This emission of radiant heat can be very noticeable under the still conditions which often occur in hot weather. Lakes and ponds can easily store considerable amounts of heat for a relatively small temperature rise. Because water bodies do not heat up very much when subjected to radiation during the day nor cool down very much at night, they act as thermal regulators. The stable surface temperature influences the temperature of the adjacent air, producing cooler temperatures in the daytime and warmer ones at night. Ground surface cover has a noticeable effect on air temperature in towns. Invariably, there are a lot of roads constructed of heavy building materials. Rain water is usually led away rapidly. The amount of vegetation cover is often small. Therefore, there is little potential for evaporative cooling. In addition, there are considerable heat inputs from vehicles, factories, heating plants, etc. All these combustion processes affect the atmosphere, decreasing solar radiation. The pollution dome alters the long wave radiation transfer. Large towns, therefore, tend to be quite a bit warmer than the surrounding countryside for most of the day. The difference is especially marked in still weather in late evening. In the morning, towns heat up less rapidly on account of their large thermal inertia. The precise extent of the town‐country difference depends, of course, on the size of the town. For a large town, the typical daily mean difference is 1‐2 degrees C. The peak difference on a still evening is much greater. Temperatures may vary by 5 to 10° C between densely built areas and city parks WIND The town‐country differences described in the preceding section can have an effect on the air movement experienced at a particular site. Wind flow is also influenced by topography. TOPOGRAPHY The terrain of an area can cause medium or large‐scale modifications to wind flow at a site. For instance, topographical features can provide protection for certain sites but at the same time over‐expose others. They can also modify the direction of the prevailing winds over considerable areas. The wind flow at the crest of a hill can be accelerated because of compression of the air streams. Air in contact with surfaces warmed by solar radiation tends to rise while air in contact with cold surfaces (for example, those experiencing night‐time radiative cooling) tends to sink. The resulting density changes generate air flow patterns which are characteristic of the particular terrains involved. Several terrain configurations cause cyclical air flows. Examples are water‐ land interfaces, hillsides and valleys. With a water‐land interface, the lake surface is warmer than the adjacent land in winter. On calm days in winter, therefore, the air tends to flow from the land to the water. On summer days, however, the land surface is warmer than the water surface and the direction of flow is reversed. In addition diurnal effects come into play in summer. During the afternoon, the and can be so much hotter than the water that a breeze off the lake develops. At night, the water surface may not cool down as much as the land so the air movement is in the opposite direction. On hillsides, solar radiation can increase surface temperatures and the hot surfaces generate uphill surface‐air streams during the day. In mountain regions this phenomenon is known as an up‐valley breeze. At night, when the surfaces are no longer receiving solar radiation, they begin to cool down. The temperature gradient decreases and finally reverses and the air circulates in the opposite direction. This is a down‐mountain breeze. In long valleys these phenomena tend to create length‐wise air movements so that the longer the valley and the higher the surface temperature, the stronger the air flow. Complex air movements can result from a combination of the valley effect and the hillside effect. TOWN‐COUNTRY TEMPERATURE DIFFERENCES In still weather, the temperature in towns is higher than that in the surrounding open country for a significant part of the day. As a result, wind flows can be generated which are similar to those found when warm masses of water are adjacent to cooler land. The urban heat island of warm air can cause a flow of wind towards the town centre. Similar flows can occur within towns, from urban spaces, such as parks, towards adjacent buildings. HUMIDITY The topography of an area and the presence of vegetation both have an effect on humidity. TOPOGRAPHY Topographical features can force the water from precipitation to flow preferentially towards hollows in the ground and create humid soil pockets. In still, sunny weather the air above these pockets is cooler than the air above adjacent dry ground. The presence of lakes, rivers and seas also has an effect on humidity. As part of the evaporation process, sensible heat is extracted from the air close to these water surfaces and the air becomes cooler and more dense as a result. Provided the vapour pressure of the cooled air remains within an acceptable range, this process can aid summer‐
time comfort. VEGETATION In sunny weather, the air close to the ground is cooled by the transpiration of water through the foliage of trees and blades of grass. The rate of transpiration drops in cloudy weather. During one week of sunshine in Germany for example, one square metre of grass will evaporate about 20 litres of water. TYPES OF MESOCLIMATE COASTAL REGIONS Along the coast, the sea has a modifying effect on the daily temperature variations found further inland. On clear winter days, for instance, the air temperature at the coast is higher than that further inland whereas in summer it is cooler and more humid. The absence of obstacles like trees and buildings and the low surface friction over the sea causes winds off‐shore to be considerably stronger than those inland. In moderate sunny weather when the land is warmer than the sea, a sea breeze can arise which blows from the sea towards the land This is most likely to occur in the afternoon and can be a significant feature in a coastal area. It is, for instance, often found in spring and summer on the north‐west coast of Europe. Such winds tend to reverse direction at night. FLAT OPEN COUNTRY In flat, open country there will be few major obstacles. Those most likely to exist will be hedges, lines of trees and nearby woods or villages. Solar radiation conditions in such areas are likely to be close to the mean macroclimatic data for the region. Wind speeds will probably be above average because of the lack of obstacles. The nature of the ground cover has an important effect on wind in open country. Rough surfaces such as scrubland and hedgerows slow down the wind close to the ground more than do smooth surfaces such as short grass or stretches of water. In open sites, the direction of the wind is similar to that found at the local meteorological station, provided the latter is itself on unobstructed terrain. WOODLANDS Trees within woods and forests constitute a screen for both sun and wind. In woodland areas apart from the clearings, shade is plentiful and winds are weak. In the day, the temperature in the underwood is lower than in open sites. The cool air masses remain in a stable position under the warm air masses and this tends to reduce even further the small amount of air flow which might be present. At night, the trees hinder the outgoing long wave radiation and this, coupled with the low air movement below the canopy, causes the night‐time temperature in woods to remain higher than elsewhere. VALLEYS The orientation of a valley has a great bearing on its mesoclimate. If a valley is oriented in the direction of the prevailing wind, the air flow may be channelled strongly along the valley bottom. By contrast, a valley which runs perpendicular to the wind flow has its bottom and lower slopes well‐ protected from the wind above. As far as solar radiation is concerned, unobstructed slopes lying between south‐east and south‐west are well‐
exposed. Slopes between north‐east and north‐west, on the other hand, do not receive much direct solar radiation. On such slopes, the sun's beam may in fact be totally blocked by the crest above. The combined influence of sun and wind can have a big impact on temperatures at individual sites. Any accumulated water in the valley bottom has a modifying effect on the daily temperature swings. It will also increase the humidity of the air or any wind flows streaming through the valley. CITIES When the regional winds are weak, the relative warmth of a large city compared to the surrounding areas can produce a convective circulation of air whereby warm air in the city centre rises and is replaced by cooler, more dense air flowing in from the countryside. MOUNTAIN REGIONS Climatic conditions in mountainous areas are significantly different from those in nearby flat open terrain. Because exposure to solar radiation and air movement are both dictated by the topography, each mountain slope has different climatic characteristics. The typical drop in temperature due to altitude may be about 0.7 degrees C for each 100 metre rise, although other factors may alter this. Similarly, a decrease in pressure of 1 millibar may typically be experienced for every 15 metre rise measured near an altitude of 2000 m. Rain and snow are more frequent in mountain regions than in adjacent flat country. The increased rainfall is brought about when wind rises up a slope and the decrease in atmospheric pressure experienced with the rise produces cooling by expansion. This, in turn, causes some of the water in the air to condense. The rain often turns to snow at higher altitudes. Wind‐ exposed slopes are much more likely to experience rain than slopes which face down‐wind. d. Microclimate At the scale of the site, man's intervention can modify the environment close to buildings, creating conditions known as the microclimate or the climate of a small area. SOLAR RADIATION The amount of solar radiation received at a site is dependent on local planting of vegetation and the shape, size and position of nearby buildings. VEGETATION Vegetation is different from other obstructions which intercept the solar radiation falling on a site. Certain types of planting change with the seasons. Many (deciduous trees, for example) provide only partial screening, filtering the incident radiation rather than blocking it completely, which can be used to advantage. NEARBY BUILDINGS Existing and potential future buildings in the neighbourhood of the site provide a fixed screen which must be taken into account in building design, especially in towns. The solar altitude and azimuth for the whole year, hour‐by‐hour, can be plotted on a solar chart. The altitude scale is shown on a series of concentric circles. The azimuth scale is set around the perimeter of the chart. The azimuth angle is read by setting a straight edge from the centre of the chart to the intersection of the required hour and date path lines and noting where it cuts the chart perimeter. Different charts are required for different latitudes. HUMIDITY The humidity of the air at a site is modified by the presence of water and vegetation. WATER Fountains, water circulating under porous pavements, ponds and canals all bring about humidification — and hence cooling — of the adjacent air, although it is important to ensure that the humidity at a site remains within the comfort range. VEGETATION The evapotranspiration process of nearby vegetation also has a cooling effect on the air. WIND Local wind conditions can be modified by the presence of vegetation, buildings and built screens. VEGETATION Shelter belts are a common way of providing protection from the wind. Conifers offer year‐round protection but obstruct sunlight in winter. Deciduous trees afford more shelter when they are in leaf in summer than when they are bare in winter. Even in winter, however, the bare branches still cause some reduction of wind speeds. BUILDINGS When wind encounters an obstacle its speed and direction are modified. A solid mass such as a building, forces the wind to go round or over it. The building side exposed to the wind is under positive (increased) pressure whereas the opposite, sheltered side experiences reduced pressure. In general, wind speed increases with height above ground. Because of the number of obstacles to flow encountered in towns, the mean wind speed at a given height is lower in towns than over open land. The size of the obstacles influences the vertical gradient. Wind flow in towns is more turbulent and changeable in direction than in the surrounding countryside. Particularly strong gusts may be experienced at the bottom of tall buildings. BUILT SCREENS Deliberate sheltering can be created by planting as seen earlier, or by means of built screens. Nearby buildings, of course, can also provide shelter from the wind. The sheltering efficiency of a long linear screen is determined by its height and permeability to wind. Close to the screen, dense screens create a larger wind speed reduction than do permeable screens. The depth of the sheltered zone, however, is not so great with a dense screen. The depth of a protected zone is proportional to the height of the screen. For a screen of limited width such as a building, the sheltered zone increases in depth from the corners to the middle. The depth of the protected zone increases with building width until the latter is about ten times the building height. At this point the depth of the sheltered zone is about eight times the building height. URBAN MICROCLIMATES Urban microclimates are particularly complex because of the number and diversity of factors which come into play. Solar radiation, temperature and wind conditions can vary significantly according to topography and local surroundings. In addition, layout density can provide further constraints: the precise plot division, the need for access and privacy, and the noise and impact of atmospheric pollution must all be taken into account. For any given project, specific design decisions need to be made on the basis of the microclimatic features which will have the greatest impact on the site. In winter, most urban microclimates are more moderate than those found in suburban or rural areas. They are characterized by slightly higher temperatures and, away from tall buildings, weaker winds. During the day, wide streets, squares and non‐planted areas are the warmest parts of a town. At night, the narrow streets have higher temperatures than the rest of the city. In summer, green spaces are particularly useful in modifying the environment during the late afternoon, when the buildings are very hot inside. Strong local winds can modify the temperature distribution described above. Usually winds in towns are moderate because of the number and range of obstacles they face. However, a few configurations such as long straight avenues or multi‐storey buildings can cause significant air circulation. Tall buildings rising above low‐rise buildings can create strong turbulent wind conditions on the ground as the air is brought down from high levels. Strong winds can flow through gaps at the base of tall buildings. To protect pedestrians from this, the turbulent flow has to be prevented from descending to street level, for example by modifying the building form or by using wide protective canopies. In semi‐open areas, adjacent buildings can be used as protective screens against some winds. The strength of the solar beam in urban areas will depend on the level of particle pollution in the air streams above the town. Some pollutants ‐ sulphur dioxide is an example ‐ have no effect on beam strength. The amount of solar radiation received at a particular site often depends on the shade cast by nearby buildings. The term 'street effect' is used to characterize the masking effect caused by buildings located across the street. The street effect depends on the height of the buildings and the distance between them as well as site latitude and street orientation and is expressed as a percentage of the usable solar gains. CONSIDERATIONS The overall objective of climate‐responsive architecture may be expressed as the provision of high standards of thermal and visual comfort within and around buildings of quality which are energy efficient in use and also in their construction. It follows that the building should respond to the environment in which it is to be built in order to take full advantage of the useful climatic effects occurring on the site and that any undesirable conditions should be minimised or eliminated. A knowledge of the regional and local climate is an essential input which will form the basis of analyses to characterise year‐round performance. With this information, and ideally in addition some reliable local experience, it is then possible to appreciate 'positive' and 'negative' climatic influences which can be modified to improve the microclimate of the site around the building. While the general macroclimate and mesoclimate of the region is beyond our influence, design changes at the microclimatic level can provide significant benefits. This approach can help to minimise or even to avoid what are often more complex and expensive measures in the design of the building itself, and in addition can improve the amenity and extend the utility of outdoor spaces. III. Focusing o
on a site. a. Lo
ocating the area In th
he care to select a site traansitional beetween temp
perate and continental co
onditions, w
we have seleccted the Czecch Republic. In fact, we can seee from this seection of the general map
p of Köppen that the Czeech Republic is in fact mo
ore conssidered as a CFb zone, which represeents a "No Drry Season, Co
ool Summer" Zone. Then again, wee can see beelow the diffferent cond
ditions from
m the Köppeem classificaation within
n the wholee country. The zo
one we will focuse on ffor the purp
pose of this exercise is the Praguee region, wh
hich is here reprresented ass a Cfb regio
on. We will not go in deetail as to w
why we havee selected tthis part of tthe Czech repu
ublic, but w
we will just cconsider a recent masssive demand
d in residen
ntial buildinggs in Prague
e and it's vicin
nity. Not on
nly has the p
population of the Czech republic increased highly over tthe last few years (CZ bein
ng the only ex‐east‐eurropean country with a growing po
opulation du
ue to immiggrants); "Praague populaation ever ggrows higheer in numbeers, now the
e number is 1 212 097. Not only th
hat last year wass record‐settting in imm
migration of 54 811 peo
ople, the number of Praague citizen
ns have step
pped over the 1,2 million for tthe first tim
me in historyy. Accordingg to the datta given by tthe Statisticcal Office ye
esterday, th
here 89. Sociologgist Karel Caada stated tthat wass the most kkids born in 2007 from the Velvet‐‐revolutionaary year 198
“thee addition ccreated by m
migration w
will increase in followingg years … given by situ
uation in oth
her regions..” Also
o, there werre 13 195 baby Prague citizens bo
orn, which iss 987 more than the lo
oss number." (Mar 21, 200
08 ABC Prague News. ), but Praguee is also sub
bject to the required reelocation of many families who haave lived
d in the 'Panelaks' (Ressidential tow
wers datingg from the ccommunist era), which are now in
n need of en
ntire refu
urbishment or for mostt of them deestruction.
A view of the south westtern part of praague with it's Panelák Maps showing localized climate classifications and annual mean relative humidity. (www.atlaspodneb.cz)
Maps showing localized solar radiation and annual mean snowfall days. (www.atlaspodneb.cz)
b.Understanding the context.
Maps showing the 14 regions of the Czech Republic. CZ has a total area of 78 886 km2 with an estimated
population of 10,424,926 and a density of 132/km2. We will for the purpose of this exercise concentrate on
the west central part of the CZ, towards the capital city of Praha (Prague). (http://geoportal.cuzk.cz/wmsportal)
Our first part in the process of sustainable construction is a simple one. We have selected a zone in close proximity of the dense capital of Prague yet locating
it within a tolerable distance of 30-45 minutes on the public transportation system (that is 35 Km from Srby to the centre of Prague, or the central station of
Halavni Nadrazi Praha. Though it should seem obvious that 'connecting' to an existing network of public transportation would not engender any new CO2
emissions, one can still consider the simple equation: CO2emission = 60g/km x 70km(roundtrip) x 5days/week 52weeks/year = 1.1 Tons of CO2 in the case of
someone travelling to city every day of the week (without holidays). We will later see if that is compensated by the gain on building in these 'better' conditions.
This topographical map of the western region of Prague shows the proximity of existing network such as
Highway, Train system, but also close and larger centers such as Kladno, just 3Km east of Srby. Kladno is
a city in the Central Bohemian Region (Středočeský kraj) of the Czech Republic. It is located 25 km
northwest of Prague. Kladno is the largest city of the region and holds a population together with its
adjacent suburban areas of more than 110,000 people. The first written evidence of Kladno dates back to
the 14th century. In 1561 the city rights were secured. Kladno was the historical birthplace of heavy
industry in Bohemia. For years, the town was home to the Poldi steel factory, the region's largest employer.
The factory still stands but has been divided into smaller entities after privatisation and changes in
ownership. The mining industry began here in 1842. The proximity to Prague helped to keep the local
economy stable in spite of the heavy industrial decline after the collapse of the communist regime. One of
the main LEGO production facilities is located here. Also one can clearly see the predominant forest
vegetation east of the lake of Turynsky and west of Kladno.
View of the town church
View of main Bus Station, Srby
View of farm houses in the region of Srby
View of farm lands in the region surrounding Turynsky lake.
Hills sloping towards Turynsky lake.
Turynsky lake, it's fauna and flora.
Turynsky lake, looking north (3 km length).
Turynsky lake, looking south, in a bitter cold winter.
c. Detailed review of specific climate conditions
General weather summary of the area of Hostivice (Half way between Prague and Srby).
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information.
General Criterias concerning the 'Comfort Zone' and tolerable limits.
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information.
Sun shading chart for SUMMER showing when ambient temperature implies stopping solar gain.
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information.
Sun shading chart for WINTER showing when ambient temperature implies increasing solar gain (heating).
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information. Temperature range chart (yearly) showing, it's relation to the confort zone of 18->26 degrees C.
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information.
Radiation range chart (yearly) showing the hourly average potential passive solar gain
Global Horizontal radiation=(direct+diffuse)xCos aincidence Chart representing the averages of radiation in comparison to temperatures. This shows us when we can
use the radiations for passive solar gain according to when our temperatures require it.
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information.
Sun shading chart for SUMMER showing when ambient temperature implies stopping solar gain.
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information. This Sky Coverage chart shows us the tendencies of the skies in that region to be covered having
implications on the radiation gains but also the natural daylight use versus artificial lighting requirements.
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information. This Chart shows the variation of the ground temp. at different depths according to the months of the year.
This informs us on the possibility of using a geothermal exchange in order to favour calorific exchanges. This chart informs us when there is potential to charge air with humidity in order to provide natural cooling.
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information.
This chart informs us of the limits of control of condensation, for eg. for the use of an 'active slab'(heat and cool).
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information.
Psychrometric chart showing for SUMMER (top) and WINTER the 'Comfort Zone' (1) with it's natural
possible extensions (2,3,4,5,6,8,9,10). We see for example in the first chart that most of the overheating
can be reduced by natural ventilation and high thermal mass calorific off-setting. In the second chart we
can see that only some of the heating required in the winter season can be provided by internal gains and
solar passive gains. This does not show what IS gained, but where it CAN be gained.
Courtesy of Climate Consultant 4.0 using EPW (EnergyPlus Weather) format climate information.
The Wind Wheel, produces by Climate Consultant, displays for each wind direction the Wind Velocity and Frequency of Occurrence along with concurrent Dry Bulb Temperature and Relative Humidity. The outer ring shows the percentage of hours when
the wind comes from each direction. On the next ring the height and color of the bars shows the average temperature of the
wind coming from that direction (light blue is in the comfort zone, blue is cool or cold, and red is warm or hot). The next smaller
ring shows average humidity (light green is comfortable, yellow is dry, and green is humid). The innermost circle shows the wind
velocities that come from each direction; the tallest brown triangle is the maximum velocity for that period, medium brown is the
average velocity, and the smallest light brown triangle is the minimum velocity. Hours when there is zero wind speed do not
appear on this chart. The graphic key to all t his information is summarized in the icon in the lower right labeled Wind Speed,
RH, Temp, and Hours.
These specific wind wheels for West Prague show us the wind tendencies according to every month. It is clear that the majority
of the winds come from the West, South-West, North-West, but also North, North-East. The majority of the North, North-Eastern
(meaning from the North, North-East) winds occur in February, March, April, May, July, but are stongest and longest in hours of
blowing in October and November when the temperatures are coming down again after the summer. The main winds are from
the West, and those occur quite stongly in the Winter but also in the Summer. In the Summer, the warmer relatively humid winds
will have to be used in order to provide natural ventilation for our building. In the winter, unfortunately we will have the problem
of trying to open up to the south in for passive solar gain and yet to try and protect ourselves from cold wind. A tight and well
insulated envelope will be hence necessary in order to increase demands in energy in order to keep our building within the
tolerable interior conditions.
This Wind Wheel recaps annualy the main directions and durations of the winds affecting the region. Once again, one can see the predominance of South Western and Eastern winds.
Courtesy of Weather Tool, part of ECOTECT.
These Wind Wheels show the main currents of both warm and cold winds according to each months (seasons). This will help us know what to protect ourselves from and which winds to embrace for natural ventilation. Courtesy of Weather Tool, part of ECOTECT.
12.01.2009
10:06:15
Page 2
Control of possible temperature depreciation according to wind convection
on
insulated
EES Ver. 8.246: #239: Ten-user license for use by, Sorane SA, Lausanne, Switzerland
façade according to U values and wind speeds.
File:WINDOW_U_TSURF_01_PARAM_02B.EES
"alpha_ext=20"
alpha_int=8
1.5
1.4
1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
EES Ver. 8.246:
0.2#239: Ten-user license for use by, Sorane SA, Lausanne, Switzerlan
0.1
0
5
10
15
20
25
30
35
40
2
Uglazing [W/m K]
T_ext=-7
T_int=20
"U_vitrage=1.1"
q_dot_vitrage=U_vitrage*(T_int-T_ext)
q_dot_int=alpha_int*(T_int-T_surf_int)
q_dot_ext=alpha_ext*(T_surf_ext-T_ext)
q_dot_int=q_dot_window
File:WINDOW_U_TSURF_01_PARAM_02B.EES
q_dot_ext=q_dot_window
q_dot_vitrage=q_dot_window
U_surf_to_surf=1.4
q_dot_vitrage=U_surf_to_surf*(T_surf_int-T_surf_ext)
2
αext [W/m K]
ep_vitrage=0.02
2
Uglazing [W/m K]
1.5
lambda_apparent=U_surf_to_surf*ep_vitrage
1.4
1.3
1.2
1.1
"Problem 21-149
1
0.9
File:WINDOW_U_TSURF_01_PARAM_02B.EES
12.01.2009 10:06:15 Page 3
0.8
The convection heat transfer coefficient for a clothed EES
person
seated
air moving
at alicense
velocityfor
of use
2 toby,
4 m/s
is given
h=8.3*V^0.6
where V is in m/s and h is in W/m^2-K. The convection
Ver.
8.246:in#239:
Ten-user
Sorane
SA,by
Lausanne,
Switzerland
0.7
coefficient at lower velocities is 3.1 W/m^2-K. Plot the convection coefficient against the air velocity, and compare the average convection0.6coefficient to the average radiation coefficient of about
0.5
5 W/m^2-K.
0.4
h=max(8.3*V^0.6, 3.1)+4.9
0.3
Use the parametric table to generate the plot."
alpha_ext=h
0.2
0.1
File:WINDOW_U_TSURF_01_PARAM_02B.EES
12.01.2009 10:06:15 Page 4
0
EES Ver. 8.246: #239: Ten-user license for use by, Sorane SA, Lausanne, Switzerland 5
10
15
20
25
30
35
40
1.4
"Press F3 to solve. Then view Plot Window 1."
= –7
T int
= 20
Uvitrage=1.1
= U vitrage
·
T int – T ext
q int
= α int ·
T int – T surf,int
q ext
= α ext ·
T surf,ext
q int
= q window
q ext
= q window
q vitrage
U surf,to,surf
q vitrage
ep vitrage
λ apparent
– T ext
1
0.8
1.4
1.2
2
T ext
UVitrage [W/m K]
= 8
2
α int
UVitrage [W/m K]
alphaext=20
q vitrage
2
αext [W/m K]
1.2
0.6
0.4
= U surf,to,surf
0
0
T surf,int – T surf,ext
= 0.02
· ep vitrage
0.6
0.2
0.2
= U surf,to,surf ·
0.8
0.4
= q window
= 1.4
1
0
0
2
4
6
8
10
12
14
16
V (m/sec)
2
4
6
Problem 21-149
8
10
12
V (m/sec)
The convection heat transfer coefficient for a clothed person seated in air moving at a velocity of 2 to 4 m/s is given by h=8.3*V0.6 where V is in m/s and h is in W/m2-K. The convection
coefficient at lower velocities is 3.1 W/m2-K. Plot the convection coefficient against the air velocity, and compare the average convection coefficient to the average radiation coefficient of
about 5 W/m2-K.
File:WINDOW_U_TSURF_01_PARAM_02B.EES
Use
the parametric table to generate the plot.
File:WINDOW_U_TSURF_01_PARAM_02B.EES
0.6
h = Max 8.3 · V
, 3.1 + 4.9
α ext = h
SOLUTION
Press
F3 to solve.
Then view Plot Window 1.
Unit Settings:
[kJ]/[C]/[kPa]/[kg]/[degrees]
(Table 1, Run 10)
2
αext = 47.04 [W/m -K]
h = 47.04
qint = 31.38 [W/m2]
Text = -7 [°C]
Tsurf,int = 16.08 [°C]
V = 15
12.01.2009 10:06:15 Page 5
EES Ver. 8.246: #239: Ten-user license for use by, Sorane SA, Lausanne, Switzerland
12.01.2009 10:06:15 Page 6
EES Ver. 8.246: #239: Ten-user license for use by, Sorane SA, Lausanne, Switzerland
2
αint = 8 [W/m -K]
λapparent = 0.028
qvitrage = 31.38
Tint = 20 [°C]
Usurf,to,surf = 1.4 [W/m2-K]
epvitrage = 0.02
qext = 31.38 [W/m2]
qwindow = 31.38 [W/m2]
Tsurf,ext = -6.333 [°C]
Uvitrage = 1.162
The conclusion of these calculations is that we need not protect ourselves from cold winds in winter (with insulation
values of around 0.5 w/m2K) so long as we have the ability of air-tightly closing the façades to the winds in winter.
1
d.Tracking the sun and its influences.
Sun path diagrams courtesy of ECOTECT.
The Sun path diagram, with existing site objects plotted, can
determine the times of the day and year in which the sun will be
available on a particular site. What we have here is a plotted sun
diagram of Prague with the coordinates being 50° 05′ 00″ N 14°
26′ 00″ E. Sun paths diagrams show the path of the sun in the sky
dome as projected on to a horizontal surface (Libbey-Owens-Ford,
1974; Olgyay, 1963; Hoke, 1996). The blue lines running form east
to west represent the path of the sun on the 21st day of each month
of the year. The sun path diagram for a given latitude can be used
to determine the sun’s position in terms of altitude and azimuth for
any hour of the year. The same diagram of altitudes and azimuths
may also be used to describe the position and size of objects from
a particular viewpoint on a site. Trees, buildings, and hills can be
described in terms of their altitude and azimuth from that viewpoint.
By plotting them on the sun path diagram, one can tell when they
will obstruct the sun and therefore shade the reference point on
the site. In our case of Srby, the lack of hills and close by buildings
makes it makes it unnecessary to plot. All we will be concerned with
is a set of trees on the eastern side of our site, and we will be able
to track this with our SunEye study. This study will allow us to see
the site as per the sun’s point of view and hence start making suggestions and developping strategies in order to maximize our solar
gains in cold months and making sure we protect ourselves during
the hot and potentialy overheated months.
East
West
21 Décembre 10 heures (heure d'hiver)
21 Décembre 11 heures (heure d'hiver)
21 Décembre 12 heures (heure d'hiver)
21 Décembre 13 heures (heure d'hiver)
21 Décembre 14 heures (heure d'hiver)
21 Décembre 15 heures (heure d'hiver)
21 Décembre 16 heures (heure d'hiver)
21 Mars 8 heures (heure d'hiver)
21 Mars 9 heures (heure d'hiver)
21 Mars 10 heures (heure d'hiver)
21 Mars 11 heures (heure d'hiver)
21 Mars 12 heures (heure d'hiver)
21 Mars 13 heures (heure d'hiver)
21 Mars 14 heures (heure d'hiver)
21 Mars 15 heures (heure d'hiver)
21 Mars 16 heures (heure d'hiver)
21 Mars 17 heures (heure d'hiver)
21 Mars 18 heures (heure d'hiver)
21 Juin 7 heures (heure d'été)
21 Juin 8 heures (heure d'été)
21 Juin 9 heures (heure d'été)
21 Juin 10 heures (heure d'été)
21 Juin 11 heures (heure d'été)
21 Juin 12 heures (heure d'été)
21 Juin 13 heures (heure d'été)
21 Juin 14 heures (heure d'été)
21 Juin 15 heures (heure d'été)
21 Juin 16 heures (heure d'été)
21 Juin 17 heures (heure d'été)
21 Juin 18 heures (heure d'été)
21 Juin 19 heures (heure d'été)
21 Juin 20 heures (heure d'été)
21 Juin 21 heures (heure d'été)
IV. Strategies, from lessons learned based on climatic conditions to solutions adopted.
As a result of the climatic study done for the region of Srby, we can now come up with a aset of strategies which will work best in those conditions in order to be the most energy efficient possible by simple
measures of shaping the building. It is those simple measures that will give this building the possibility
of being efficient without the requirement of technical elements such as photovoltaic cells, or windmills
even though these might come in later but in small quantities in order to make our building entirely self
sufficient. Following is a list of those preliminary measures.
-Fully glazed Southern orientation (south east if possible to warm up starting the morning)
East west 25 % and little north opening. In the case of an individual house with enough clearance on
each east and west sides of it, we can say that we can actually make use of the east and west façade
for winter heating, morning with east, and evening with west. Obviously we will need to protect those
faces in summer when the sun comes at the same height as the winter sun either with non deciduous
trees, with external shading, or with fixed elements designed in reaction to the path of the sun.
Southern exposure
South-eastern exposure
-Shape of building to allow for best proportion of solar facing glazed window compared to ther total surface area of envelope. In this example we convert the one storey 225m2 house above into a two storey
225 m2 favoring the southern face as the longest.
Doubel storey, Southern exposure
Double storey, South-eastern exposure
-Roof to be vented to the exterior with well insulated ceiling below. The air trapped in the protected
and shielded zone act as a buffer zone and help
reduce the quick fluctuations in temperatures but
also allow for a major reduction in inflitrations in a
zone where it is not always best controled.
Vented roof.
-Floor plan to be worked according to heat and natural daylight requirements. Proper set up of program within the house
will allow for better natural daylight in the required spaces,
influencing greatly the reduction of electricity requirements
due to lesser use of artificial lighting. Also these rooms will
be able to collect solar energy during the day achieving
without heating better comfort conditions.
Passive solar house by Stillman and Eastwick.
Osco house in Ticino (CH) by F. Pedrinis.
Orientation according to major winds to capture natural ventilation. We have previously proven that
a well insulated and air tight building prevents us from having to protect ourselves from winter winds
which is speccially important in our case since we have winds useful for summer cooling coming
from the same directions. For that reason it will be important to follow certain guidelines to orient
our building but also the openings dedicated for natural ventilation properly. Natural ventilation can
come in different forms such as cross ventilation, stack ventilation but also night ventilation.
Series of guidelines for chaneling the wind around the
building according to it’s form, shape and orientation.
Dynamic FlowVent (Software) analysis will allow
for virtual testing of wind reactions to specific
building shapes.
Example of Stack ventilation. Air exit
needs to be at high point in order for
self lifting of the air and suction from
lower intakes. The stair shaft can
usualy act a a good base for stack
ventilation. Also a venturi effect at
the top can induce and help such a
system.
-Determining if type of building is for quick heating or continuous heating (pied à terre ?). This will
make vary the need for inner thermal mass. A building which is rarely occupied is best built with little
thermal mass and good insulation; this way it is quicker to heat or cool. We will here consider a case
where the building is in fact inhabited regularly. This implies building with at least some high internal
mass, such as stone, earth, or concrete in order to store the heat from the day inthe winter and to allow to cool the day during the summer (dephasing of peaks). Still able to build the house in light weight
framing, we will make sure to place the thermal mass where it is exposed to sun rays. A thick walled
fireplace can also usualy be used as heat or coolth storage.
Storage of solar calories in thermal mass thoughout the house.
Thermal mass will be most effective with a large surface
of contact to the ambient wamrth (or coolth), which is
why such systems as this stacking of bricks can be most
effective for such purpose. (Inspired by A. Rüedi)
-Location of heat source according to plan in order to best distribute. Centralizing the fireplace
or the source of heat in plan can allow a better distribution around the house and have better
time responses according to demands in fluctuations of heat and coolth requirements. This will
generaly allow a better programing fo the heating system according to times of occupation.
Use of ground’s inertia though selective insulation
F.L. Wright Cooperative Homesteads House, Detroit
-Gains from buried zones or ground slab with surroundin insulation. Earth sheltering reduces heat
loss and heat gain in two ways: by increasing the resistance to heat flow of the walls, roof and
floor, and by reducing the temperature difference between inside and outside. At a depth greater
than 0.5 m below the earth’s surface, daily temperature fluctuations are negligible. The effectiveness of earth contact for heating is considered very good according to Technique 19 of Sun, Wind
& Lightb y G.Z. Brown and Mark DeKay. Earth sheltering takes three basic forms: either sinking
the building into excavated earth, berming the earth up around the building, or building the structure into an existing hillside. In all these forms, earth sheltering may range from partially covered
walls to totally covered walls to completely covered walls and roof. The energy and other effects
of earth-sheltered roofs should be carefully weighed againsat the costs of structure, waterproofing, and maintenance.
WARNING: This is in the case that there isn’t any
water current close by. If that is the case the energy
would be lost and NOT stored. Depending on the
type of water presence geothermal pick up might be
able to be operated.
-Control of radiation and illumination. The main strategy implying full glazed southern orientation
and exposure, being excellent for passive solar gain and natural daylight sourcing brings us a
ng
Internal Traffic
and
Circulation
major dilemma.
Half of
the
year, we are welcoming the sun’s radiation and all year its illumination,
but in the warm/hot half of the year (say may to september) we become at high risk of overheaernal ting. Trying
The best
designed
spaces
promote
to limit
the interior
number
of active
systems or artificial means of reducing the intake of the
we then
risk of
loosing natural daylight and hence at risk of increasing the
rrespondsun’s rays
a smooth
flow become
of internalattraffic
through
use of proper
artificial
daylight
(electricity).
Logic tells us that in the warm periods of the year the sun is
s
space
planning
and by carefully
high
and
that
all
we
would
need
is
a
tation,
addressing proximity and work flowcanopy to protect us from the sun’s rays. Then again, that is
of loss
of indirect
diffuse natural daylight, which in winter becomes very precious.
satisfy the beginning
requirements.
Mechanical
conveyancing
proximity
systems should be necessary only for
Design excellence
should make essential use and disabled access. By
passive
proper placement of stairwells and
gning your
circulation spaces, we can encourage
a plant
passive conveyancing and promote a more
of the
efficent workspace as well.
he dark.
Internal circulation requirements should
also consider designing for accessibility an
part of every
design. canopies
Our twointegral
storey building
with louvered
Beautiful Foster + Partners example of canoFoster and Partners’ sustainability policy is
based on a cumulative approach. We have
the expertise, talent, and passion to give
our clients sustainable solutions that complement the imaginative, innovative, and
high-quality design for which the practice
is renowned. We firmly believe that sustainability enriches design excellence.
The practice’s work includes masterplans
for cities, the design of buildings, interior
and product design, graphics, and
exhibitions. These can be found throughout
the world; from the United Kingdom,
Europe, and Scandinavia, to the United
States, Hong Kong, Japan, China, Malaysia,
Saudi Arabia, and Australia. While each
project is fundamentally unique, and
requires a subtly different approach, our
architecture benefits from our wealth
of experience and interactions with
different cultures, peoples and climates.
We are dedicated to achieving the best
possible environmental performance, while
delivering on time and to budget.
pies, though in hot south of France climate
Our designs develop through teamwork
and a thorough evaluation of all problems
and potential solutions. Our efforts
cover every aspect of the design, with a
particular emphasis on the environmental
impact of our buildings.
There are simple ways to calculate summer sun
rays; whereas lightshelves only tend to bring light
ighting simulations
more evenly to the back of the room, yet generaly
ered images
that can
reducing
the amount of light brought in the room.
Sunshine School, California, Horn & Mortland
Louvered sun shading canopy.
A-5
As we can see there are several ways of blocking
the summer sun, such as camopies, may they be
louvered or lightshelves. Overall a precise calculation of the minimum-maximum requirement is needed in order to optimize the amount of hot sun rays
blocked for the amount of natural daylight let in. For
this we will be using softwares such as Relux-Radiance which will yield results of sun penetration in
Dayligth Factor (% of light inside compared to the
available one outside, according to a standardized
covered sky). Obviously, the plan layout will also
reflect this need for certain rooms requiring more or
less light. Also the use mechanical external shading
louvers will allow for a better control and comfort of
the conditions inside the building.
Externall Blinds
bility/Sustainability Policy
y/Sustainability Image Library
lons2005/Sustainability/Powerpoints and Videos
Relux-Radiance Pseudocolors results with
radiance rendering.
Skylight.
Nordjyllands Kunstmuseum
-Last but not least come the elements that are a little more technical such as the build-up of the envelope, the use of air-air heat exchangers for the renewal of fresh air, the general built of the frame,
or even the use of active floors and walls in order to provide a better comfort inside the building.
-An important part of making a building with a very low demand in energy implies
being able to keep the conditions inside the building with the least fluctuations.
For that we will be most likely using triple glazing with a low U value (conductance) high G value (light penetration allowance). these U values typicaly revolve
around 0.5 to 0.6 W/m2K which with the window framing (wood) usually gives us
something around 0.8 to 0.9 W/m2K. Though this might seem like a small value
compared to double or even simple glazing, one should not forget that it is still
aroung 5 times worse than a ‘good’ wall. Our walls will most likely less than 0.2
W/m2K which is easily achievable with 14 to 15 centimeters of insulation. What
is very important here though, is the external position of the insulation, as it will
allow us to reduce the thermal bridges and the infiltrations to a minimum. Any
kind of balcony or exterior extension to the house will be somehow independent
from the buildings structure in oder to help there to.
Wall build up with external insulation and
triple glazing.
-Creating a tight building is one thing, one should not forget
that there is a need for air renewal. Air which has been breathed, becomes poor in oxygen and more humid. This is why
creating an air-tight building serves no purpose if we do not
have a controled air renewal system which can recuperate the
warmth of the ‘used’ air exiting to pre-warm the new fresh air
in winter (and vice versa in summer). This is why we will be
using an air-air heat exchanger as air renewal is one of the
biggest loss in heat in a building in winter. Our system will allow for about 40-50m3/h/person of air to exit the building with
a calorific exchange in the process.
-Apart from the ecological and economical
advantages of using wood, one will have the
ability to prefabricate with vey good precision,
and potentialy ‘explode’ the 3D designed
structures into a simple set of plans. One
major disadvantage of wooden frames is that
they are poor in thermal mass; which is why
the latter will be achieved through the installation of stone or concrete slabs in specific
areas fo the building.
-A big part of the impression of comfort in a
building comes from the radiation of the floors
and walls. A cold wall in summer can actually
give the impression of coolth even if it is hot
inside. This is why we will try and control that
comfort zone inside our buidling with an active
system in our walls and floors. This implies
setting up a set of conduits in the build up in
order to run water at specifc temperatures all Lightweight wooden frame for a
controled by a building maintenance system. house implies many advantages.
V. Testing our solution in TRNSYS for first evaluation of consumption.
Running of the TRNSYS simulation yields the below results. We
have ran the solution without cooling or even ventilation (considering that natural ventilation was the source of air renewal at a rate
of 90m3/h. Results give us a general consumption in KWh for the
whole volume heated (225m2 by 2.7m in height)
This first table shows us the results ran with an external shading system activated 50% of the time.
The result is 4280 KWh / 225m2 = 19 KWh/m2, which being a good result represents a version where
part of the ‘good’ solar radiation is lost in winter (id est when they could be used).
This is why we would also like to look at a version ran without any external solar shading ( Shading
would be of course triggered in the summer in order to reduce the overheating)
The result is 3140 KWh / 225m2 = 14 KWh/m2, which being an even better result and represents a version where all of the ‘good’ solar radiation is gained in winter (id est when they can be used).
Both these solutions imply an enevelope engineered to reduce the thermal bridges to the minimum (id
est external insulation, no balconies structuraly connected to the façade, et cetera).
Running of the double storey ‘solar optimized’ version.
Running of the TRNSYS simulation yields the below results. We
have ran the solution without cooling or even ventilation (considering that natural ventilation was the source of air renewal at a rate
of 90m3/h. Results give us a general consumption in KWh for the
whole volume heated 2X 113m2 by 2X2.7m in height)
This table shows us the results ran with no external shading system activated at any time.
The result is 988 KWh / 226m2 = 4.37 KWh/m2, which being a excellent result represents a version
where natural ventilation will have to play a very important role in summer. The efficient box, making gain
of all the solar radiation in winter will have to protect itself effectively from them in summer. The graph
below shows the potential for overheating in summer.
Organigram of the TRNSYS model of the one storey 225 m2 house built on our Srby, Czech Republic site and controled with the local meteorological values. Present in the center is the
building itself with all it’s values of insulation, orientation et cetera. Around it are the systems such as the controled natural ventilation, but also the heating systems (including internal and
solar passive gains), all revolving around a Psychrometric chart taking into consideration all relations between humidity and temperature. Courtesy of TRNSYS.
Comparing cases according to their Heating Degree Day values.
Heating degree day (HDD) and cooling degree day (CDD) are quantitative indices designed to reflect the demand for energy needed to heat or cool a home or business. These indices are derived from daily temperature
observations, and the heating (or cooling) requirements for a given structure at a specific location are considered
to be directly proportional to the number of heating degree days at that location.
More specifically, the number of heating degrees in a day is defined as the difference between a reference value
of 18°C and the average outside temperature for that day. The value of 18°C is taken as a reference point because experience shows that if the outside temperature is this value then no heating or cooling is normally required.
Occupants and equipment within a building usually add enough heat to bring the temperature up to a more comfortable level.
The tables below are written in French and DD is translated as DJ for Degrés-Jours. They will give us a base
comparison for general similarities in heating requirements.We are here looking to compare the values of the DJ
20 / 12 between Prague and Coire in the Grison region in Switzerland. We can basicaly say that they are very
close
to similar.
REFERENCE:
C:\_Users\METEO\HORAIRE\Prague_dry.meh
MOIS
DJ 14/14 DJ 16/16 DJ 18/18 DJ 20/20 DJ 22/22 DJ 24/24 DJ 14/ 8
1
2
3
4
5
6
7
8
9
10
11
12
ANNEE
DJ 16/ 8
DJ 18/10 DJ 20/12 DJ 22/14 DJ 24/16
500
417
338
197
70
21
7
10
55
175
331
437
562
473
400
253
116
54
24
29
100
236
391
499
624
529
462
312
170
97
54
63
151
298
451
561
686
585
524
372
231
146
98
111
210
360
511
623
748
641
586
432
293
201
152
169
270
422
571
685
810
697
648
492
355
259
211
231
330
484
631
747
500
417
323
161
20
0
0
0
0
118
321
432
562
473
379
195
26
0
0
0
0
144
377
492
624
529
462
266
76
8
0
0
44
233
451
561
686
585
524
344
147
45
9
18
116
326
511
623
748
641
586
421
230
109
55
58
215
415
571
685
810
697
648
485
324
214
120
133
292
484
631
747
2556
3137
3773
4456
5169
5894
2292
2648
3254
3934
4732
5585
Heating Degree Days (Degrés-Jours) for Prague. Altitude: 340m
Seda Tönük, Kutlu Sevinç Kayýhan
•
•
•
•
•
•
•
•
Thermal zone on the northern façade
Enclosed northern façade
Living rooms on the southern façade
Open - glazed envelope on the southern façade
Natural ventilation — cross ventilation
Sustainable materials use
Active usage of solar energy
Heat insulation for thermal comfort
etc.
Heating Degree Days (Degrés-Jours) for Coire (CH). Altitude: 580m
For reference, the Trin house in Coire by Andrea Rüedi, consisting
of 230 m2 and representing a similar amount of Degree-Days demands between 0.83 and 1.11 KWh/m2/year.
Figure 5. House with Zero Energy Heating, Trin / Andrea- Gustav Rüedi (1994)
VI. Conclusion.
It is after a serious understanding of the local climatic conditions that we have been able to put
forth s et of strategies which will allow us to build in the best conditions or that is in a way which
will consume the least energy to ‘run’ the building. We can see below for example that using such
good practice can drasticaly reduce the demands in energy.
Courtesy of Foster + Partners.
opy of this document may be found on lons2005/Sustainability/Sustainability Policy
ges in this report may be found on lons2005/Sustainability/Sustainability Image Library
presentations relating to Sustainability may be found on lons2005/Sustainability/Powerpoints and Videos
B-31
On the other hand another important set of data is key to the development
of a sustainable project and that is all the materials used within the construction of the latter. It is usualy not considered but the ‘Grey Energies’ required represents a huge amount of energy. Which is why we
will need to interest ourselves closely to the life cycle of materials.
Courtesy of
Energy Manual,
Detail, 2008
Considering the embodied energy in materials reveals the importance of the life cycle model. Besides the energy consumption, every use of every material triggers environmental impacts due to
the resulting flow of resources. Starting with the need for a building, such flows can only be reduced, not eliminated .
The availability of raw materials was critical for the development of prosperity in the industrialised
countries. It was only through the exploita¬tion and processing of those materials that industrial
prosperity became possible at all. According to the rules of the marketplace, dwindling resources
makes a commodity expensive; and permanent availability of other resources is not guaranteed,
as the disputes involving gas, oil and water are already proving. Worldwide, buildings consume
about 50% of all resources in their construction and operation. They represent the critical factor
for dwindling resources and environmental problems. On the other hand, owing to their low-tech
status and high material consumption, building materials are predestined for considerable improvements in efficiency. Other sectors, like the automotive or electronics industries, have pledged
themselves to saving resources and increasing efficiency, and derive competitive advantages
from that. Without new impetus from within the building sector, new developments or compa¬rable
pledges, political demands for similar objectives in the construction industry are certainly only a
matter of time. In order that mate¬rials remain available permanently, open materials chains, especially those for non-renewable raw materials, must be closed wherever possible.
Considering the life cycles of materials represents a new and to a certain extent not yet comprehensively defined approach which brings together knowledge from various social and economic
sectors. However, the total life cycle cannot be fully predicted and planned. So it is therefore
often the need to guarantee options, e.g. adaptation to suit actual usage requirements that is
important. «Flexible fit» strategies are suitable here: increased durability to prolong the potential period of use, simpler internal fitting-out to enable changes to the internal layout, reversible
connections between components to ease deconstruction, and recovery of materials for the
building materials life cycle.lone can force a decrease in the use of materials.
Considering the embodied energy alone can force a decrease in the use of materials. Complying
with constructional necessi¬ties, e.g. through comprehensive exploitation of material capacities, simple assemblies, adapted durability, use of renewable materials, leads to a much lower
consumption of both energy and resources.
However, further factors come into play in the life cycle approach, e.g. secondary emissions due
to cleaning or changes to the interior air due to emissions from materials. Many of these factors
can only be considered and described as potential factors. They are not necessarily triggered
by negative aspects and indeed do not have to be used positively, but they are key elements in
viable planning for the needs of the future. And it is precisely here that we find the potential for
innovation provided by the advance planning of the life cycle.
Courtesy of Energy Manual, Detail, 2008
Project Name
Project No.
National Botanic Garden of Wales
COMPONENT
A - APPRAISAL
B – STRATEGIC
BRIEFING
0861
C – OUTLINE
PROPOSALS
Project Type
Leisure &
Retail
D – DETAILED
PROPOSALS
Site Characteristics
SITE AND
CLIMATIC
RESPONSE
Siting and
Orientation
Landscaping,
Topography and
Vegetation
Biodiversity
Promotion
Transport and
Communications
Site
Selection/Develop
ment Type
Density
Environmental
Impact
FORM AND
MASSING
Location
Climate Zone
Wales, UK
E – FINAL
PROPOSALS
Temperate
F/G –
PRODUCTION
INFORMATION
AND TENDER
DOCUMENTATION
H – TENDER
ACTION
Area
Budget
5,800
m2
£$€
J- MOBILISATION
32 M
L – AFTER
PRACTICAL
COMPLETION
- public botanic
garden
- public transport
access (Sustrans
network)
- redevelopment
- institution
- leisure
- public attraction
- local employment
- development of
local industries
Tools
Environmental
Responses
Environmental
Impacts
Tools
EXTERNAL
ENCLOSURE/
BUILDING
ENVELOPE
INTERNAL
CONFIGURATION
Glazing
U-values and
insulation levels
Responses to Form
and Orientation
Tools
Internal Traffic and
Circulation
Comfort Psychological
Comfort Physiological
Space Organisation
Internal Zoning
Tools
Overall Strategy
Heating
Cooling and
Ventilation
ENVIRONMENTAL
SYSTEMS AND
CONTROLS
Lighting
- biomass boiler
- highly insulated
distributed mains
- variable
temperature
control to track
external conditions
- variable speed
pumping
- 80% of space
naturally ventilated
- automatic off
lighting control by
daylight
- 80% of space
naturally lit
Controls
Tools
Energy Strategy
Energy Sources
Energy
Consumption
ENERGY AND
WATER
Water
Consumption
Water
Management
MATERIALS AND
WASTE
- solar heat storage
- temperature
control regime
- wood burning
biomass base load
- oil peak load
cover and backup
91 kWh/m2/y
21.6 kgCO2/m2/y
- rainwater
recycling for WC
flushing
- borehole water
supply
- on-site sewage
treatment via reedbed installation
Selection and
Sourcing
Building
Components
Life Cycle Analysis
Waste
Management
Tools and
Standards
Grid from Foster + Partners detailing the important points to focuse
on throughout the process of establishing a sustainable project.
mramos\B9888Project Form01040923.doc
C-5
Extracted from Sun, Wind & Light,
G.Z. Brown and Mark Dekay, 2001
Bibliography ‐Les Climats, Mécanisme et répartition, A. Godard – M. Tabeaud, Armand Colin, 2002 ‐Les Climats Européens, M. Pavan, Editions de Vecchi, 2005 ‐Petit atlas des climats, L. Chémery, Petite Encyclopédie Larousse, 2003 ‐Les saisons et le mouvements de la terre, P. Causeret – L. Sarrazin, Belin pour la Science, 2001 ‐Continental Climate. (2008). In Encyclopædia Britannica. Retrieved November 04, 2008, from Encyclopædia Britannica ‐ "continental climate", 2008, Merriam‐Webster. ‐ Climatology, Mc Graw Hill, Encyclopedia of Science and Technology, 2005 ‐ environ(ne)ment : approches for tomorrow, G. Clément ‐ P. Rham, Skira, 2006 ‐Design With Climate, Bioclimatic approach to architectural regionalism, V. Olgyay, Princeton University Press, 1963‐73. ‐Introduction to Architectural Science: The Basics of Sustainable Design, S. Szokolay, Architectural Press, 2004 ‐Sun, Wind & Light Architectural Design Strategies, G.Z. Brown and Mark DeKay, J. Wiley & Sons, INC., 2001 ‐Energy Manual, Sustainable Architecture, Hegger – Fuch – Stark – Zeumer, Birkhäuser Verlag AG. ‐ Energy Conscious Design, A Primer for Architects, J Goulding ‐ J Lewis, Theo Steemers, Batsford for the commission of the European communities, 1992 ‐Architectures Durables, Pierre Lefèvre, Edisud, 2002 ‐Architecture climatique. Une contribution au development durable. Tome 2 : Concepts et Dispositifs, P. Lavigne ‐ A. Chatelet, P. Fernandez, 1998 ‐Développement durable. Pourquoi ? Comment ?, Pierre Chassande, 2002 ‐L’Architecture Ecologique, D. Gauzin Müller, Le Moniteur, 2001 ‐Architecture Ecologique: une histoire critique, James Steele, Actes Sud (Thames & Hudson), 2005 ‐Design with Nature, I. McHarg, 1969. ‐Solar Architecture in Cool Climates, C. Porteus – K. MacGregor, Earthscan, 2005 ‐Climate Considerations in Building and Urban Design, B. Givoni, Van Nostrand Reinhold, 1998 ‐La conception bioclimatique, S. Courgey – JP. Olivia, Terre Vivante Ecologie Pratique, 2006