Closed House Conditions

All windows in the house (including upstairs) should be kept closed during the whole radon measurement. Tamper-evident stickers may be placed on the windows, and must be intact upon retrieval or the test will be invalid.

All exterior doors need to be kept closed. Normal entry and exit is permitted. (Shut door behind you). HVAC systems should be used with the fan in AUTO mode. System should be between 67 - 77 degrees F.

Whole house fans are not to be used. Ceiling fans, dehumidifiers, and air filters that are not built-in equipment to the house should not be operated within 20 feet of the radon testing devices.

Fireplaces are not to be used during the test period. The flu should be kept closed. Clothes dryers, range hoods and bathroom fans should be used in moderation. 2-3 loads of laundry per day is fine.