Dodgemen, thanks for the support.The problem with A-A-Xers is that they don't pressurize the home. They take out as much air as they bring in. When the clothes drier, bath fans, kitchen hood, or central vac operate, they cause negative pressure sucking air from ajacnt space. The key controlling the amount of outside air like a constant small amount. Comfort and heating/cooling is reasonable with no more than fifty cubic feet per min per 1,500 square feet of space.