Radon Mitigation by Mechanical Ventilation without Unintended Adverse Consequences

Common Practices vs Best Practices

  1. Install a fan to deliver outdoor air into the breathing zone
  2. 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.
  3. Install a table lamp timer to turn system on and off several times a day
  4. Install a light switch to turn system on and off.
  5. Install a blue oil-filled U-tube manometer to indicate
    1. That the fan is running
    2. That the fan is running, but the filter is clogged

Best Practices

  1. 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.
  2. 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.
  3. Look for and if found, seal “Radon Fountains” with self leveling urethane sealant, not canned foam.