Builder's radon pipe: does it need a fan?

Does a builder's radon pipe need a fan?

Only if your test comes back at 4 pCi/L or higher. A pipe with no fan is a passive system. PA DEP says to test after you move in, and if the level is still 4 or more, have a certified mitigator add a fan.

What is a builder's radon pipe?

Some new homes are built with radon-resistant features. PA DEP says these make up a passive radon system. DEP says passive suction works like a fan-powered system, but relies on natural pressure differences and air currents instead of a fan to draw radon up from under the house.

DEP also says passive suction is generally not as effective at lowering high radon levels as a system with a fan.

How do you know if you need a fan?

Test. PA DEP says every new home should be tested after you move in, even if it was built radon-resistant. The only way to know if the passive system is doing enough is a test result.

• Under 4 pCi/L: EPA says to consider fixing between 2 and 4. A fan is one way to bring it down further.
• 4 pCi/L or higher: DEP says the passive system should be activated by a certified mitigator adding a vent fan.

What does adding a fan cost?

PA DEP says a qualified mitigator can add a vent fan to an existing passive system for about $300. DEP says fixing a home costs much less when a passive system was put in during construction.

Who can add the fan?

A PA DEP-certified radon mitigation company. Once there's a fan, it's an active system, so DEP's rules apply:

• The fan must not be in or below a livable area. It goes in an unoccupied attic or outside.
• A warning device must be fitted so you know if the system stops working.
• The home must be tested within 30 days of installation, but no sooner than 24 hours after the fan is running.