from the ground up - The Tyee

thick. Also, the window frames are exceptionally airtight,typically incorporating two ore more rubberizedgaskets. The frames are also quite thin.“The frame is your enemy, because the frame is lessefficient. There’s more thermal conductivity throughthe wood than through the glass and the air,” Dürfeldsaid.The doors are similarly constructed. And all are sealedto the vapour barrier with more specialized tapes.“To my knowledge there are no North American madewooden doors or windows that will meet the Passivhausstandards,” Dürfeld said. “This could be abusiness opportunity for the right company.”Buildings that breathe easyOne of the most common misconceptions about Passihausand other airtight buildings is that they are stuffy.The truth is that because they are actively ventilated,they tend to harbour significantly higher indoor airquality than comparable buildings.The name Passivhaus was selected to describe theintention that such buildings eschew “active” heating(such as a boiler or conventional forced-air furnace)or air conditioning systems. But nearly every Passivhausbuilding does include an active ventilationsystem called a heat recovery ventilator, or HRV.An HRV is a device that draws cold air from theoutside through one side of a series of baffles that actas a low-pressure heat exchanger. Indoor air passedthrough the other side of those baffles as it is expelledfrom the building. Thus the indoor “heat” is “recovered,”as fresh air entering the building is warmed.Heat recovery ventilators typically operate quietly andblow air much more gently than a forced-air furnace.The airflow is barely perceptible, but by runningcontinually. In Austria House, the air is completelyexchanged every 90 minutes.“It’s constant. You can never shut this thing off,” Dürfeldexplained.The final 10 per centSuperinsulation and extreme air-tightness are the coreof the Passivhaus approach, and provide most of theenergy savings. Dürfeld estimated that Austria Houseuses about 10 per cent of the energy of a comparablebuilding.“During construction, we were able to heat the housewith one of those little 1,500-watt ceramic heaters,”he said. “One day I remember, it was about sevenbelow outside. Just really, really cold. But all yourinterior surfaces, floors ceilings windows walls, wereall within about a degree and a half of each other.”Austria House generates much of what little heatingenergy it requires from a low-tech ground-sourcesystem.Dürfeld and his crew buried three long ABS plastichoses beneath a 20-meter-long yard in front of thebuilding. Dürfeld described them is “giant slinkys,”and said they were placed about two meters deep thencovered with gravel.The fluid that runs through these hoses is cooler thanair in summer, and warmer than air in winter. It runsthrough a compressor, thereby creating about fourkilowatts of energy. That’s enough to heat the building’shot water and at times further raise the temperatureof incoming air flowing through the HRV.Lost Lake PassivhausAustria House worked for its builders. As seen onAustrian TV, the 2010 Winter Games looked at timeslike an infomercial for the Austria Passive HouseGroup. When the games were through, they gave thehouse to the municipality of Whistler for use as across-country ski base.The building has since been renamed Lost Lake Passivhaus.Lost Lake Passivhaus -- nee Austria House -- is workingfor Whistler, too.“We always had the vision of trying to leverage somesort of a country house in this location to help supportour cross-country operation,” said the city’s RogerWeetman.46