Radon Mitigation by Mechanical Ventilation without Unintended Adverse Consequences
Common Practices vs Best Practices
- Install a fan to deliver outdoor air into the breathing zone
- Install homemade filter or no filter at all. Do not tell owner of need for filter maintenance every 60-90 days until after full payment is made.
- Install a table lamp timer to turn system on and off several times a day
- Install a light switch to turn system on and off.
- Install a blue oil-filled U-tube manometer to indicate
- That the fan is running
- That the fan is running, but the filter is clogged
- Check Breathing Zone pressurization / depressurization with air conditioner operating. If greater than negative 2 pascals, duct leakage may be causing radon problem. If greater than positive 2 pascals, duct leakage may be masking even higher radon levels.
- Check air conditioner for dehumidification performance. Measure Delta t cooling performance. Air conditioner must cool air more than 17 degrees after 20 minutes of cooling operation.
- Look for and if found, seal “Radon Fountains” with self leveling urethane sealant, not canned foam.