Q. I live in a house with a Radon remediation system we hope keeps the radon level at an acceptable level. In the summer we rarely use the air conditioning and love to let in the fresh air. I would like to install a whole house fan to create a cooling breeze and increase air circulation. Someone had mentioned that a whole house fan would create a draw that would pull more radon up through the foundation into the home. Is this true? Is a whole house fan not recommended for a house with a radon problem?
A. On the face of it that might seem to pose a problem but letís look a bit closer to see if we can reach a conclusion. Years ago, and Iím talking about 25 years, when the Radon issue first came to the attention of home owners and building professionals many looked a bit askance at the whole issue regarding a danger from Radon as some form of invisible snake oil. The hype was deafening. It took on the flavor of the disease du jour and on one side there was a stampede of what looked like opportunists who see dollar signs where perceived danger lies and on the other were those who doubted. I was a doubter. I needed lots of corroborating evidence and data from those who both know what they are talking about and who donít have a dog in the fight. Studies were conducted world wide and I watched as the evidence piled up pointing to the presence of radon in dwellings to be a potential lung cancer cause. It does. For me that revelation came some years ago.Radon comes into the house from the soils upon which the house is built. It is called a gas and I wont quibble with that definition but the particles are so tiny as to be measured in atomic parts. Itís radioactive and what happens when one inhales a Radon particle it becomes lodged in the recesses of the lungs and the body canít readily expel it. It then fires off an electron-- part of its atomic decay process-- and if that flying electron hits a DNA strand in a lung cell and damages it that sets up a precancerous condition that can devolve into full blown lung cancer. Some areas have more Radon occurring naturally in the ground than others so at some point your house was tested and the result apparently was high enough-- above a number of 4.0 picoCurries per liter of air in the house-- to warrant installing an active Radon mitigation system. Installing a mitigation system like yours is simple and straightforward. First the perimeter of the basement floor where it meets the foundation wall is sealed tight with caulk. The installer, utilizing your already present sump pit, seals the sump pit while installing a PVC vent pipe that looks just like a plumbing stack that runs out of the house to a point just above the roof line. The installer places a low amperage in-line fan on the pipe that is attached to a power source and the low amperage fan, running constantly, depressurizes the area under the houseís basement slab, intercepting the Radon and venting it to the exterior. I have gone into homes with this sort of a system installed and operating and retested for Radon and I have never seen this system fail-- it does the job. Now, you want to place a whole house fan-- the type that fits flat on the ceiling and while running pulls air into the house from open windows aiding in house cooling and propels this air up into the attic where it leaves the house through the attic vents. Whole house fans are great and can buy you a lot of comfort without having to resort to air-conditioning. I grew up in house with no central air but we had a big old whole house fan the sound of which put me nicely to sleep many hot summer nights. But the whole house fan is only run with the windows open. Turn it on with the windows and doors closed and ashes in the fireplace will fly out into the room and you'll only do that once. Since the Radon mitigation system is sealed and works on the underside of the basement slab, my sense is that the whole house fan canít compete with it. You could prove the point by installing a home Radon test kit that you can buy from a home center or online to check it. Iíll bet you wonít get any radon while using the whole house fan.