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SOPHIE, A European Database on Indoor Air Pollution Sources Paper # 1039 Eduardo de Oliveira Fernandes1, Philomena M. Bluyssen2, J.L.Molina3 1 FEUP, Universidade do Porto, 4200-465 Porto, Portugal; 2TNO, P.O. Box 49, NL-2600 AA Delft, The Netherlands; 3AICIA, University of Sevilla, 41092 Sevilla, Spain. ABSTRACT The Indoor Air Quality issue is mostly centered around a triangle of topics: health and comfort effects, pollution sources and ventilation. Strategies for good IAQ include giving priority to source control since ventilation techniques have proven not to respond properly in every circumstance. Ventilation systems are themselves often a cause of indoor pollution, and ventilation levels are also being subject to constrains imposed by energy efficiency targets in buildings. In the context of the European Union RTD Programme, some projects were launched since 1991 aiming at identifying the main causes for the indoor pollution and defining and preparing a tool of some universal character to enable industry and professionals to allow to relate the strength of the pollution sources with the IAQ conditions. SOPHIE is a database containing information on hundreds of materials as pollution sources and chemical substances as pollutants, and, a model allowing to integrate the information of the strength of the sources to calculate the ventilation rate that assures a proper level of IAQ. This paper presents the main features of SOPHIE and the conditions under which the data were obtained, namely the agreed protocols adopted by a number of prominent laboratories in Europe. A special focus will be made on the way SOPHIE can be used to provide information for designing buildings for better IAQ but, probably more important, as a reference database for the enhancement of the cleanliness and sustainable character of materials and other building products towards the future. INTRODUCTION Indoor Air Quality (IAQ) is becoming more and more a key issue in today’s health policies. As personal air exposure becomes more dependent on the indoor environment, where people can spend more than 90 % of their life time, IAQ needs to be tackled together with and in a necessary continum to the more common ambient air quality approaches. IAQ is mostly centered around a triangle of topics: health and comfort effects, pollution sources and ventilation. It is difficult to deal with health effects at indoor levels, as epidemiological studies are, in general, a very complex task and because concentrations of pollutants in indoor air are usually very low. The most common types of effects can be identified as being: sick building syndrom, building related illnesses such as allergies and asthma, and cancer. Yet, there is a lack of a foundation for the definition of what is acceptable IAQ from the health point of view as no generally accepted procedure for evaluation of the effects of the multiple low level exposures is agreed [1]. There are three commonly presented strategies to promote good IAQ: (a) source control, meaning that sources of indoor pollutants shall be avoided or confined or their strength be minimized; (b) dilution, in tune with the fact that exposure will be less if, for the same time duration, the concentrations of the pollutants in the air are lower; and (c) the removal, basically through filtration and ventilation techniques which have proven not to respond properly in every circumstance. Despite all progress in filtration technology, still many questions remain about the performance of filters. One area of performance in question includes what could be called the secondary pollutants eventually generated in the filter matrix itself, such as odours [2]. In the past, ventilation has been presented as the panacee for good IAQ. Yet the so-called fresh air must come from a clean outdoor area. Furthermore, it has been already abondantly illustrated that ventilation systems can themselves be causes for non negligeable indoor air pollution [3]. However, the fact that the criteria to establish the ventilation rates adequate to each situation have been missing and that other types of constraints emerged, namely the trends to reduce the energy consumption, led to a lot of changes in recommended ventilation rates in the last 150 years. Recent studies have shown that to guarantee good IAQ for comfortable and healthy indoor environments in the future, more detailed efforts must be made giving priority to the source control approach [2]. The concept of sustainability will also encourage that materials and energy used in buildings converge to the same ultimate objective: to make healthier and more environmental friendly buildings (i.e., buildings contributing to a better environment both indoors and outdoors) [4]. In the context of the European Union RTD Programme, a few projects were launched since 1991 [2,3,5,6] aiming at identifying the main causes of indoor air pollution and defining a database as a tool of some universal character to enable industry and professionals to relate the pollution sources with the IAQ conditions through the ventilation rates. The expected final result would have been a set of protocols and of formats to collect, store and manipulate data that could be recognised by growing shares of the technical and professional communities. Some of those protocols were tested in parallel with the development of guidelines and standards in several fora [7,8,9,10]. The most relevant products of the whole ten year programme would be a database containing information on hundreds of materials as pollution sources and a model allowing to integrate the information on the strength of the sources and to calculate the ventilation level that assures proper IAQ. This paper presents the database SOPHIE and some of its main features. A special focus is made on the way this database can be used to provide information to designers for developing buildings with better IAQ and, more importantly, on its potential as a reference database for the enhancement of the cleanliness and sustainable character of materials and other building products towards the future. SOPHIE – SOURCES OF POLLUTION FOR A HEALTHY AND COMFORTABLE INDOOR ENVIRONMENT SOPHIE is the acronym adopted for a database of indoor air pollution sources, including building materials and furnishings and ventilation system components. It represents the result of the work of a vast network of laboratories in Europe developed under the sponsorship of the European Commission. It aims to document the most important indoor pollution sources and to create a model to establish the link between the strength of the pollution sources and the ventilation rate and its consequences in terms of IAQ in a given space. SOPHIE is a tool that can become a reference database and function as a basis for the launching of more practical or specific databases and labelling frameworks at different levels. This could be by differentiating construction products or by reflecting the diversity of state or national contexts. Its data can be handled and compared with a particular high degree of confidence as its results have been obtained from different laboratories following the same protocols and checked through different processes (i.e. pilot studies of inter-calibration at the European level) [11]. The structure of SOPHIE is illustrated in Figure 1. Figure 1: SOPHIE Structure Modelling of Ventilated Spaces Building Materials Protocol for Characterisation of Indoor Air Pollution Sources Coupling Diffusion Pre-existing model for dynamic thermal behaviour of buildings Sorption and Air movement Testing in Chambers Chemical emission Toxicological Information Sensory evaluation Model Database on Indoor Air Pollution Sources Toxicological evaluation Informative Data Userfriendly Programme SOPHIE It contains information on some HVAC-components but the more prevalent information refers to construction materials. Table 1 makes a balance of the type of materials tested and of how many tests were performed during the two major campaigns of the development process of SOPHIE. Those materials have been tested according to standard procedures for testing chambers [9] and for chemical analysis [10]. A sensory assessment was also performed [12]. Two product ages were generally considered for the materials tested: 3 and 30 days. In some cases an intermediate age of 14 days was also considered. SOPHIE is more than just a static list of materials organised by several different criteria related to their contribution to the indoor air quality. Once the emission rate of chemicals by the different materials was determined, the next step was to establish the model to link the concentrations of those chemical substances (pollutants) in a given space with a certain level of ventilation rate and with the dynamics of a certain thermal environment indoors. That is why a major tool is incorporated to enable the linkage of the ventilation conditions with the actual level of the IAQ conditions for a certain type of occupation, including the nature and the extension of materials employed. It is a dynamic model quite ambitious but probably with the merit of establishing a frame with enough generality and broadness to allow for further developments. The model has certainly many limitations, some related to the status of the current knowledge and others due to the lack of appropriate information. It is clear nowadays that sorption/desorption effects play an important role on the actual levels of the concentrations of certain pollutants depending on the different ambient conditions, but, above all, on the interaction of the material/substance. The fact is that the values for specific coefficients of adsorption or desorption of a particular chemical substance in a given material are generally unknown. Recent studies have been made in order to obtain the information needed on the sorption/desorption coefficients for different coupling material/substance. [13] So far, that work has only been done for a very limited number of cases. Given the hundreds of substances and materials that can be present, that limitation represents probably the major bottleneck to the wide application of the model. Table 1. Description of emission sources and related tests investigated for SOPHIE. Type of Source Number of sources FLOORING 56 WALL 33 CEILING 2 CONSTRUCTION 14 OTHER 14 HVAC-Components.# 16 1994 – 1997 1998 – 2000 # Number of Chemical Tests Number of Sensory Tests 3rd day 14th day 30th day 3rd day 14th day 30th day 53 26 2 10 13 18 14 5 0 3 2 0 55 29 2 14 14 0 57 14 0 17 11 39 28 0 0 8 6 0 57 14 0 17 11 0 86 46 24 0 68 46 106 32 32 10 67 32 85 50 Tests not related to time but air volume It is well known that there are many pollutants which cannot be traced chemically. That often makes sensory evaluation absolutely necessary. Unfortunatelly, there has been some controversy regarding the meaning of the different procedures for sensory assessment [12], in particular, on the way through which the relationship between the sensory information and the ventilation rate can be established. That controversy became more apparent in Europe in the late 90’s to the point that it influenced the development of SOPHIE negatively. Since the scientific community has not been been able to reach the necessary clarification on this matter so far, the sensory information, as well as the information on the toxicity of some selected substances, will be part of the database but cannot be worked out through the model. This data will be available only on an informative basis. DATA FROM TESTING A database can only be of interest if the quality of the data is assured, in particular, in regard to their relative coherence and consistency. Therefore, the experimental work to be performed by independent and reliable laboratories has to be conducted using the same procedures. The procedures adopted under a former agreement among participating laboratories were the same as already existed in the European standards for chamber operation, sampling and test specimen preparation [9]. It has to be recognised that there was some simultaneous work between the development of SOPHIE and the standardisation process. Therefore, SOPHIE can emerge as a precursor having a patrimony of experience and gathering a set of data that would not be possible to have today, if the approval of the standard was to precede the tests. In this context, the agreement among several laboratories in different countries, obtained previously to the test campaigns, was a key element for SOPHIE and represented a good background for the development of the work in the standardisation process. The method for determination of VOCs is defined on the standard ISO DIS 16000-6 [10]. It defines that the VOC emissions shall be quantified by their own response factors. This is in contrast to the major part of the internationally available data where quantification has been done as toluene equivalent. MODEL The dynamical modelling of the effect of ventilation strategies on indoor air quality of buildings had as its main objective to obtain a model able to evaluate the indoor air quality in a particular zone of a building in terms of levels of concentrations of pollutants. The modelling exercise was completed taking into account the effect of possible different ventilation strategies and thermal dynamics of the building as well as the effects of sorption and desorption of chemical compounds in building materials [13]. The effect of ventilation strategies can not be calculated without considering the thermal dynamics of the building, which is very important for comfort and health purposes even if no attention is paid to IAQ. The effects of sorption and desorption can not be evaluated without the knowledge of the temperature of the indoor air and those of the different materials. So, an important piece in this method is the dynamical thermal model of the building in which the specific IAQ model has been introduced. The sequence of the work was as follows: non steady state diffusion model of mass and heat transfer through building materials; sorption (and desorption) model of the diffusion of pollutants (mass) through the building materials; and model of the air movement including both the natural air movement and the forced air movement simulated by the behaviour in jets. Coupling all the previous phenomena a new model was created, representing a tool for calculating the dynamical thermal behaviour of buildings. Then the model was introduced in the database and software was produced for including the results of tests and presenting the SOPHIE outputs. POTENTIAL FOR BETTER INDOOR AIR There is nowadays a clear trend towards the production of cleaner materials for buildings. The reasons are obvious from the point of view of the environment in general but also from the perspective of the indoor air or the quality of the indoor environment. The quality of the indoor air is linked to the quality of the ambient air because supply air tends to be taken from outside – recirculation has become less recommended – and ventilation is an important energy demanding service. In OECD countries the top energy consumer is the building sector accounting for about 40% of the total energy used. In a recent document issued by the European Commission (Green Paper) [14] it is clearly assumed that the strategies for CO2 economy cannot be successful if the control of the diffuse consumers such as transportation and buildings is not assured. In regards to buildings, ventilation is definitely one of the major causes of energy consumption. More ventilation is, in principle, beneficial for a better IAQ and less ventilation is beneficial for less energy used and consequently for better outdoor air. Therefore, the aim shall be to obtain a solution that creates the conditions, by a wise source control methodology, to have no more than just the right amount of ventilation necessary to assure that the absolute needs for good IAQ are guaranteed. EXAMPLE Let us consider a room in an office building, located in Seville (Spain). The office has 9 m 2 of floor area, 3 m height with a window (2.12.1 m2) in the south façade. Internal gains of 30 W/m2 (sensible) are considered. The floor is covered with a carpet which emits 46 g/h/m2 of formaldehyde (among other pollutants, see table 2). Table 2: Emission rates (g/h/m2) from floor material The ventilation fans are on during the working period (7-15 hours) assuring 2 air changes per hour. In the base case 0.5 renovations are of outdoor clean air. Qualitative results for formaldehyde concentrations in the vertical central plane cells of the room are shown in figure 2. When the fans are off there is only natural movement of the air (Fig. 2a) . There is a clear stratification of the concentrations near the floor, partly broken by the movement of air due to the free convection near the window. When the fans are on, with the return vent located near the ceiling, the cell shapes change to accommodate the jet trajectory. It can be seen how the stratification changed being apparent some higher concentrations in the cells just below the supply vent. Results regarding the impact on energy use can also be obtained. Figure 3 shows the energy demands for heating and cooling, for the base case (a) and when the outdoor air supply increases from 0.5 to 1.5 air changes per hour (b). The heating demand increases from 823 kWh to 1000 kWh, whereas the cooling demand increases from 320 to 446 kWh. On the other hand, maximum formaldehyde concentration is reduced from 0.0026 ppm to 0.0013 ppm. Making some energy recovery via heat exchangers or free cooling can reduce the increment on the energy demand due to higher ventilation rates. On figure 3 (c) the results of incorporating free cooling controlled by temperature are shown. The heating demand is reduced to 810 kWh and the cooling demand goes down to 294 kWh. a b Figure 2. Qualitative results for formaldehyde concentrations: a) – no ventilation; b) ventilation with jet on the wall Heating Base Case: 2 ach + Free Cooling, T Base Case: 2 ach (1.5 O.A.) Base Case: 2 ach (0.5 O.A.) Heating Cooling Heating Cooling 150 100 100 100 50 50 50 0 0 11 200 150 9 200 150 7 200 5 250 3 250 1 250 Cooling 0 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 a b c Figure 3. Heating and cooling demands for base case (a), higher percentage of outdoor air (b) and free cooling (c) HOW TO USE SOPHIE The question of how access to SOPHIE is achieved has been raised for a few years now. A marketing plan was created, a questionnaire to different industry representatives was promoted and several options are being considered to launch a process of making SOPHIE available in a dynamic and interactive way. Every time the concept has been presented and further steps in the development of this database have been shown, more interest was generated. From these marketing and promotion activities around SOPHIE, quite a bit of interest in SOPHIE has been generated not only from the industry and research community in Europe, but also from USA, Japan, and Australia [13]. Most of the interested parties accept all the current available features. However, many would prefer to add some features such as commercial names of products, access to complementary info on products, a classification/labelling system and a link to other databases. English is not a problem. Most are interested in becoming a member of an organisation around SOPHIE. The problem is that SOPHIE is not specific and asks for a sound engagement of a few entities to make sure that it can keep developing in the future and does not loose its momentum. Among the alternative ways of accomplishing this is through the creation of a club of users through which the adoption of the concepts and practices become tested and eventually enhanced exploring a tool of interaction among manufacturers, designers users and regulators. This possibility could be reached in the very near future through a “thematic network”, a specific European RTD action for information and dissemination. In this process, to be launched in the next months, the interest of laboratories with experience on testing materials, labelling and certification will be essential. Nowadays there is a great interest for materials labelling. Several labelling schemes are available at the national level. SOPHIE may not be directly useful to such an activity but it could help the labelling process, in particular if a European (or even global) labelling system would to be implemented. The fact that SOPHIE can rank an expressive number of materials and chemical substances it can act as a reference or background database. Every time a new product is tested and recognised as being a clean or a low polluting material according to the current criteria, it can be introduced into the database. This way, SOPHIE can be kept updated in terms of new products and of cleaner products assuming that cleaner raw materials and components are used more and more in a continuous emulation process towards a more sustainable world. CONCLUSIONS There is a need to enhance the access to methods and protocols in order to widen the assessed information and to create the opportunities and means for management of indoor air pollution sources in order to give credibility to the information used when documenting their performance. IDMEC SOPHIE is certainly one of those tools that may contribute towards a more systematic and universal approach to the IAQ issues beyond the interests of groups, be it of manufacturers or other professionals. Besides other potential uses, there seems to be a special “niche” of market for SOPHIE as a reference database, closer to laboratories and institutions where the data is obtained and the products are certified. SOPHIE can be a strong element as a reference tool in the process for labelling materials in a coherent sound trans-national context. In Europe, actions are on the way to make certain SOPHIE is enhanced and exploited in such a way that it contributes to the creation of healthy and energy efficient buildings. Contributions and opportunities for interaction with other Nations are nevertheless very much appreciated. AKNOWLEDGMENTS SOPHIE was sponsored partly by the European Union in the JOULE programme (DGXII) and involved several laboratories from different countries namely: FEUP - Faculdade de Engenharia da Universidade do Porto, Portugal, acting as co-ordinator. Other participants were: Technical University of Denmark, Department of Energy Engineering, Denmark; TNO Bouw, Division Building and Systems, Netherlands; VTT Chemical Technology – Technical Research, Finland; CSTB – Centre Scientifique et Technique du Bâtiment, France; AICIA – Asociacion de Investigacion y Cooperacion Industrial de Andalucia, Spain; and FriedrichSchiller - University Jena, Erfurt, Germany. REFERENCES 1 Mølhave, L., Overview of Indoor Air Quality in Europe, Workshop on Urban Air, Indoor Environment and Human Exposure, European Commission JRC, Thessaloniki, April 2000 2 Bluyssen, P.M., AIRLESS Publishable Final Report, Joule III Programme, EC, Delft, The Netherlands, February 2001. 3 Bluyssen, P.M., Fernandes, E. de Oliveira, Fanger, P.O. and al., European Audit Project to Optimise Indoor Quality and Energy Consumption in Office Buildings, Final Report, Delft, The Netherlands, March 1995. 4 Fernandes, E. de Oliveira, Energy Use and Links with Air Quality, Workshop on Urban Air, Indoor Environment and Human Exposure, European Commission JRC, Thessaloniki, April 2000. 5 Fernandes, E. de Oliveira, Clausen, G., European Database on Indoor Air Pollution Sources, Final Report, Porto, Portugal, February 1997. [6] Fernandes, E. de Oliveira, Bluyssen, P.M., and al, MATHIS – Materials for Healthy Indoor Spaces and More Energy Efficient Buildings, Indoor Air 99, Edinburgh, 1999. [7] ECA (European Collaborative Action “Indoor Air Quality and its Impact on Man”), 1997, Report Nº 18, Evaluation of VOC Emissions from Building products – Solid Flooring Materials, European Commission, Joint Research Centre, Environment Institute, EOR 17334 EN 1997. [8] ECA (European Collaborative Action “Indoor Air Quality and its Impact on Man”), 1997, Report Nº 19, Total Volatile Organic Compounds (TVOC) in Indoor Air Quality Investigations, European Commission, Joint Research Centre, Environment Institute, EOR 17675 EN 1997. [9] CEN ENV 13419 Building products – Determination of emission of volatile organic compounds: Part 1 – Emission test chamber method; Part 2 – emission test cell method; Part 3 – Procedure for sampling, storage of samples and preparation of test specimens. [10] ISO DIS 16000-3: Determination of formaldehyde; ISO DIS 16000-6: Indoor air and emission test chamber air – determination of VOCs; active sampling on Tenax TA, thermal desorption and gas chromatography MSD/FID. 11 Cochet, C., Kirchner, S. and De Bortoli, M., VOCEM – Further development and validation of a small test chamber method for measuring VOC emissions from building materials and products, Final Report, 1998. 12 Kirchner, S., MacLeod, P., Ramalho, O. and Regoui, C., Sensory testing in MATHIS and AIRLESS, Contribution to the debate on the sensory issues in MATHIS project. First twelve month report from MATHIS project, Porto, Portugal, 1998. [13] Fernandes, E. de Oliveira, MATHIS Publishable Final Report, Joule III Programme, EC, Porto, Portugal, March 2001. [14] Commission of the European Communities, Green Paper, Towards a European Strategy for the Security of Energy Supply, Brussels, 29.11.2000, COM (2000) 769 final.