During a short-term Radon test, close windows, and doors to the outside and keep them closed, except for normal entry and exit. If you are taking a short-term test lasting 2 – 7 days,
The Environmental Protection Agency (EPA), has set forth the following conditions which must be met prior to and during the test period until the testing equipment is retrieved to help ensure an accurate reading:

1) All windows, doors, and crawlspace vents must be closed 12 hours before the start and during the entire test period. Normal entry and exit through doors is acceptable except for lower level walkout doors and windows and any sealed with anti-tamper tape.

2) Internal-external air exchange systems (e.g. whole-house fans, window fans, window air conditioners with outside damper open, etc.) must not be used 12 hours before the start and during the entire period of the test.

3. Occupants should avoid excessive operation of clothes dryers, range hoods, bathroom fans and other mechanical devices that draw air out of or into the building.

4. Radon test devices must not be moved or tampered with in any way during the test period.

5. Normal operation of heating and air conditioning systems as well as fireplaces or wood burning stoves used for heating purposes is permissible, although fireplaces and/or wood burners can only be used if no other source of heat is available.

EPA 402-R-92-003