- Slides: 23
What is Passive Housing? A passive house is a building in which a comfortable interior climate can be maintained without active heating and cooling systems (Adamson 1987 and Feist 1988). The house heats and cools itself, hence "passive".
Why choose Passive Housing? Economical reasons Save on installing a heating system Save on heating bill For a typical 100 m/square house built to passive standards there would be roughly an 85% reduction in heating bills. Environmental reasons Uses less heating so produces very little carbon dioxide. For a typical 100 m/square passive house there is an almost 94% reduction of CO 2 emissions.
How are Passive Houses so efficient? Solar Orientation Thermal Mass Insulation Thermal Bridging Air-tightness HRV
Solar Gain Which is the best way to orientate the house in order to optimise solar gain. A)
Solar Gain B)
Solar Gain C)
Solar Gain Aspects of Solar Gain Building Orientation Climate of area Site specific’s Building Orientation Sun rises in the east travels along the south and sets in the west. Climate of area This must be taken into account when designing the house.
Solar Gain Climate of Area The climate vary as you move through different areas. Depending on the annual sun-shine in an area the design must compensate for this. Even if the areas are close the climate will still vary.
Solar Gain What are the site specific’s of this house? South facing view of house.
Solar Gain Site Specific’s Objects which block the suns rays must be compensated for. Trees Hedges Buildings Hills/Mountains Etc.
Solar Gain How do we compensate for the amount of glazing, local climate and site specific’s. Triple glazing with insulated frames Insulation
Thermal Mass What is Thermal Mass? Thermal mass is used in Passive Solar Housing in order to regulate the heat of the house. (Prevent it from getting too cold or too hot)
Thermal Mass How is this achieved? Concrete, tiles etc are used in the walls and floors. The heat from the sun is absorbed by these walls and floors and is released during the night.
Overhangs are positioned over windows in passive solar houses so as to prevent all the summers sun rays entering the house. This stops the house from over heating in summer.
Insulation Why Insulate your Home? Insulation prevents the loss of heat through the outer envelope of the house. Insulation has to be well positioned so as to prevent the external and internal envelopes connecting. Why?
Thermal Bridging What is thermal bridging? A thermal bridge is created when materials that are poor insulators come in contact, allowing heat to flow through the path created. Where must be prevent thermal bridging from occuring? Windows Walls Floor Roof Etc.
Thermal Bridging How do we prevent thermal bridging? Prevent direct contact between the outer envelope and inner envelope. Use insulation to prevent these thermal bridges.
Air tightness Why is Air tightness important? Air tightness is one of the most important aspects of passive housing. If air tightness is achieved the exchange of warm and cold air will be prevented. This improves the heat retention in the house. § How is it achieved?
HRV Why is a ventilation system needed in passive houses. Ventilation system is required as no air enters and exits the house as it is air tight. Moisture, dust mites etc. will need to be removed from the house. How does it work?