Download Passive House Standard Video Tutorial

Passive House Standard Video Tutorial – Information Pamphlet
1.
Introduction
Passive House is an energy-performance building standard which achieves year-round comfort and excellent indoor
environmental conditions with minimal space heating or cooling demand. Passive House projects provide very high
level of thermal comfort with whole-building even temperatures. The concept is based on minimising heat losses and
maximising free-heat gains, thus enabling the use of simple (small) building services.
The appearance of a passive house building does not need to differ from conventional buildings and living or working
in them does not require any lifestyle changes. Passive House projects are typically light and bright due to large
glazed areas designed to optimise solar gains, as well as healthy buildings in which to live and work due to fresh air
supply through the ventilation system.
The Passive House standard is a construction standard developed by the Passive House Institute (PHI) in Germany
(http://www.passiv.de) following the first ever project in 1991. The Standard can be met using a variety of design
strategies, construction methods and technologies and is applicable to any building type.
2.
Definition of the Passive House Standard
The Passive House standard is a specific construction standard for buildings with good comfort conditions during
winter and summer irrespective of the climate in which they are located. Typically this includes optimised insulation
levels, high performance triple glazed windows (typically the weakest part of the envelope), minimal thermal bridges,
very low air-leakage through the building, utilisation of passive solar and internal gains and good indoor air quality
maintained by a mechanical ventilation system with highly efficient heat recovery.
The primary focus in building to the Passive House standard is directed towards creating a thermally efficient
envelope which dramatically reduces heat losses and makes the optimum use of free heat gains in order to minimise
space heating requirement. There are also limitations on the amount of primary energy that can be used by a building
for such uses as hot water, lighting and appliances.
Structural air-tightness (reduction of air infiltration) and minimal thermal bridging are essential. A mechanical
ventilation with heat recovery system (MVHR) is used to supply controlled amounts of fresh air to the building. The
incoming fresh air is pre-heated via a heat exchanger, by the outgoing warm stale air. If additional heating or cooling
is required, a small efficient back-up system (preferably using a renewable energy source) can be used to increase or
decrease the temperature (and humidity) of the fresh air supplied to the building.
3.
Criteria used to define the New-Build Passive House standard



Heating energy demand
or Building heating load
Useful cooling demand



Primary energy demand
Building airtightness
Excess temperature frequency
 15 kWh/(m². year)
 10 W/m²
 15 kWh/(m².year) + additional allowance for
dehumidification in humid climates
 120 kWh/(m².year)
 0.6 air changes per hour (ACH) @ 50 Pascal
O
 10 % (overheating is defined as >25 C)
-1
Note: the measurement units for airtightness is typically ACH, but sometimes h is used, as well as 1/h. All three
mean the same thing, namely the number of air changes per hour (h).
4.
EnerPHit – the Retrofit Passive House Standard
PHI introduced in 2012 a variation on the above criteria especially for retrofitted projects, called EnerPHit. The
performance criteria are broadly similar to those above, with the most notable exceptions pertaining to heating energy
demand, relaxed to 25 kWh/(m².year), and airtightness levels which is 1.0 ACH @ 50 Pascal.
This material was prepared by Passive House Academy and is based on the Passive House standard developed by the Passive
House Institute in Germany
5.
Typical Performance Indicators for the Passive House Standard
In the table below some of the key performance indicators for Passive House projects are listed.
It is important to note that specifying U-values is dependent upon many variables (including building compactness
(ratio of surface area to volume), orientation and climate) and can only be verified through testing the performance of
the building design in the Passive House Planning Package (PHPP) software. Nevertheless, the U-values listed in
below will give some impression of the kind of insulation required in cold temperate climates.
Measure/Solution
1. High Performance Envelope
Walls, roof and floor (opaque elements)
Key Performance Indicator
2
Windows and doors
Thermal bridge free details
Airtightness
U < 0.15 W/m K
Note: insulation in the roof can be on the flat ceiling (‘cold roof’
or on the slope ‘warm roof’
2
U < 0.85 W/m K
Linear heat coefficient (Psi value) Ψ < 0.01 W/mK
n50 < 0.6 air changes per hour
2. Heat Recovery/ Air Quality
Ventilation counter flow
air to air heat exchanger
Electrical efficiency of the MVHR
Ventilation (supply) flow rates
Minimal Space Heating
Efficient small capacity heating / cooling
system
Absolute minimum heat recovery efficiency > 75% (most
+
modern MVHR now achieve 90% efficiency)
3
Maximum 0.45 Wh/m
3
Min 0.3 air changes per hour and 30m /person/hour
Post heating via ventilation air usually possible
Biomass, oil or gas boilers. In mixed (cold and hot climates) a
heat pump is likely to be the best choice.
3. Passive Solar Gain
Glazing
Solar Orientation
Overheating
Hot water solar heating
Solar heat gain coefficient (SHGC) > 60%
Minimal glazing to north, take care with west and east facing
glass due to risk of overheating
Horizontal shading likely required on southern elevation to
prevent overheating in summer
Area of solar collectors to be determined by house size and
occupancy (note – use of solar collectors is not a requirement of
the Passive House standard)
Top Three Principles:
1. Passive House is an internationally recognised high performance energy efficiency standard;
2. It is applicable to all building types, can be implemented in all climates and is defined according to
both new-build and retrofit criteria; and
3. The focus in achieving the standard is directed towards a superb building envelope considering
insulation, windows, airtightness, thermal bridging and heat recovery ventilation.
Want to Learn More?
Please visit www.energyquarter.com for further on-line video tutorials on the Passive House.
This material was prepared by Passive House Academy and is based on the Passive House standard developed by the Passive
House Institute in Germany