You CAN open windows and doors!
Jeff, there is nothing permanently sealed about Passive Houses. Although the envelope is air-tight, in mild weather you can leave your windows open without affecting the temperature all that much. Everyone loves fresh air and it's always an option. In a cold winter, if you do open the windows (not sure why you'd want to) you would simply lose your efficiency. The indoor air quality in a Passive House is much better, however, than the external air quality. Fresh air is constantly introduced from outside, run through the ERV, filtered through a Merv 15 air filter and is warmed or cooled through the heat exchanger with 95% efficiency. Throughout the house there is never more than a 3?? delta in temperature. It's perfect for people with allergies and any PH occupant will tell you it's the freshest air they've ever breathed in a home.
