The GuardianPlus Air System delivers whole-house HEPA filtration and fresh air ventilation at a price point that rivals single-room equipment. Eight beta sites have been set up around the United States where people suffering from respiratory ailments such as asthma or allergies are testing the system. It cleans and conditions the air for an area up to 2,500 sq. ft., compared with a single-room filtration system that treats up to 400 sq. ft.