Where does the radon fan get installed?
Short answer: Per EPA guidelines, the fan must be installed in an unconditioned space — typically the attic or mounted on an exterior wall. Fans are never installed inside finished living space, in basements, or in crawlspaces.
The radon fan placement is one of the most important — and most often violated — code requirements.
The rule: the fan and any fan-side pipework must be installed in an unconditioned space, never inside the home's living envelope.
Why? Because the fan side of the system is under positive pressure. If a joint or the fan housing develops a tiny leak, that leak pushes radon-laden air *into* whatever space the fan sits in. If the fan is in a basement or closet, that's radon being pumped directly into your living space.
Acceptable fan locations:
- Attic — most common in Iowa City homes, clean look from the exterior
- Exterior wall mount — common when attic access is limited
- Garage (if unconditioned and not connected to HVAC)
Never acceptable:
- Basement (even unfinished)
- Inside any conditioned interior space
- Crawlspace
- Garage with conditioned air or HVAC ducts
If you've inherited a system with the fan in the basement, it should be relocated. We do these retrofits regularly.