What is a Radon Mitigation Fan?

Radon is a radioactive, cancer-causing gas found in soil and rocks that can make its way through a home's foundation into the home's inside air. A radon mitigation fan is part of an overall radon mitigation system installed in residential homes and other buildings to reduce or eliminate detectable levels of radon in the air. Understanding what a radon mitigation fan is requires understanding radon, the danger it brings into a home, and the role a radon mitigation system plays in reducing that danger.

Radon gas is undetectable to the human eye and nose and requires a special test to determine the levels in your home. It is widely accepted that no radon levels are safe for ongoing exposure and, if the radon levels are found to be 4 picocuries per liter (pCi/L) or higher, you should take immediate steps to get rid of the radon in your home. Even at lower levels, many experts recommend taking steps to reduce the amount. Reliable tests to determine radon levels can be found in most hardware and home improvement stores for a nominal fee. Radon detectors are also available for purchase online.

Radon enters the air you breathe through the natural breakdown of uranium in soil, rocks, and water. It is estimated to cause many thousands of deaths each year, because breathing air containing radon can cause lung cancer. Radon can be found all over the world and can get into any type of building — including homes, offices, and schools — and result in high indoor radon levels. Your greatest risk for exposure is most likely at home, where you spend most of your time.

There are several methods to reduce indoor radon levels, but the system primarily used in homes consists of a vent pipe and a radon mitigation fan. Called a soil suction system, it pulls radon from beneath the house and vents it to the outside, away from windows and other openings. By venting above and away from the home with the aid of a radon mitigation fan, the radon never enters the home and is diluted in the outside air. Also known as sub-slab depressurization or active soil depressurization, this radon reduction system does not require major changes to your home, because the vent pipe often runs outside. Sealing foundation cracks and other openings can make the system more effective and efficient.

A similar method to reduce radon levels in homes with crawlspaces involves covering the earth floor with a high-density plastic sheet. A vent pipe and radon mitigation fan are used to draw the radon from under the sheet and vent it to the outdoors. Called submembrane suction, this system — when properly applied — is highly effective at reducing radon levels in homes with crawl spaces.

Choosing the right radon mitigation fan and system depends on the design of your home and other factors. When installing a radon mitigation system, you must be aware of potential moisture issues. Mechanical ventilation can cause too much moisture to build up inside the home, leading to harmful mold and mildew. Lowering radon levels requires technical knowledge and skills and, whenever possible, you should use a contractor specifically trained to fix radon problems. Testing for radon and installing radon mitigation systems has become a specialized industry, including private certification programs for radon mitigation professionals.