Some degree of radon is present in nearly all soils, and it is present in the air we breathe. When it it seeps into confined spaces, such as into crawl spaces and basements through cracks in building foundations, it can concentrate and become hazardous. Blocked ventilation in those areas can further exacerbate the problem. Elevated levels of radon over a long period of time can cause lung cancer. Clear the air with a radon fan. Our radon mitigation fans vary by housing material, voltage and other considerations. Most fit ducts of 4-1/2” diameter. For more on proper residential ventilation, see our residential exhaust fans and our whole house fans.