bridges vol. 11, September 2006 / Green Buildings Focus
by Guido Wimmers

Living in a passive house can be described as a 365-day stay in a climatic spa. Fresh air flows in constantly, but traffic noise, insects, dust, soot, and pollen remain outside while no heat is lost. No cold building surfaces generate asymmetrical radiation temperatures. All surface areas are equally warm - even the windows. The result is simply a healthy and comfortable indoor environment.

Although occupants of passive houses may open windows whenever they want, they won't have to. A passive house is continuously supplied with fresh air via the ventilating system and, because of the heat recovery, it always has a comfortable temperature. This has several advantages: unlike window ventilation, fine filters in the ventilating system keep out dirt and pollen; and air quality within the house is always excellent, even when occupants are away and/or windows are never opened.

The ventilation system with heat recovery in a passive house is not an air conditioning system that recirculates inside air. Bacterial growth can be a problem in recirculation air systems with cooling, but only if they are poorly maintained. Fan and valve noises are almost completely eliminated by sound control measures like vibration isolation mounts and low air speed. Jet nozzles guide incoming air along the ceiling, from which it uniformly diffuses throughout the room at barely perceptible velocities.

Does this sound like a house you'd like to live in? Welcome to the building of tomorrow!