Short-term measurements lasting between two and 90 days should be made under closed-building conditions. Closed-building conditions are necessary for short-term measurements in order to stabilize the radon and radon decay product concentrations and increase the reproducibility of the measurement. Windows on all levels and external doors should be kept closed (except during normal entry and exit) during the measurement period. Normal entry and exit include a brief opening and closing of a door, but--to the extent possible--external doors should not be left open for more than a few minutes. In addition, external-internal air exchange systems (other than a furnace) such as high-volume, whole-house and window fans should not be operating. However, attic fans intended to control attic and not whole building temperature or humidity should continue to operate. Combustion or make-up air supplies must not be closed.
In addition to maintaining closed-building conditions during the measurement, closed-building conditions for 12 hours prior to the initiation of the measurement are a required condition for measurements lasting less than four days, and are recommended prior to measurements lasting up to a week in duration. Normal operation of permanently installed energy recovery ventilators (also known as heat recovery ventilators or air-to-air heat exchangers) may also continue during closed-building conditions. In houses where permanent radon mitigation systems have been installed, these systems should be functioning during the measurement period.
In addition to maintaining closed-building conditions during the measurement, closed-building conditions for 12 hours prior to the initiation of the measurement are a required condition for measurements lasting less than four days, and are recommended prior to measurements lasting up to a week in duration. Normal operation of permanently installed energy recovery ventilators (also known as heat recovery ventilators or air-to-air heat exchangers) may also continue during closed-building conditions. In houses where permanent radon mitigation systems have been installed, these systems should be functioning during the measurement period.
- All windows and external doors to be kept closed except for entry and exit
- Whole house and window fans to be turned off
- Attic fans can continue to operate
- Combustion and air makeup supplies remain open
- Heat recovery systems to operate as normal
- Any permanant radon mitigation system should be running during and at least 12 hours before test
- If less than four day test closed building conditions should begin 12 hours before test begins
Advanced Property Inspections
Phone 262-458-4176
Radon Testing in SE Wisconsin
Radon Testing in SE Wisconsin