Will the radon system make my basement cold or noisy?
How loud the fan actually is
Modern inline radon fans (the standard Fantech, RadonAway, or AMG units we use) run at roughly 45 to 55 decibels at the fan housing. For comparison, a quiet refrigerator runs around 40 dB, a refrigerator humming in a quiet kitchen around 50 dB, and a normal conversation around 60 dB.
When the fan is mounted in the attic above an unfinished bedroom, you can usually hear it if you stand under it and listen. From down in the bedroom with the door closed, most homeowners do not notice it at all. When the fan sits on the exterior wall outside the house, inside readings drop close to ambient.
We never put the fan in the basement living space. That is part of the AARST and EPA installation standard. Code requires the fan to be on the conditioned-air side of the home only if a switch is installed, and only above the lowest level of occupancy. In practice, that means attic or outside.
Why the basement stays at the same temperature
A radon mitigation system pulls air from under the slab, not from inside the home. The fan pulls on a sealed PVC pipe that draws air out of the gravel layer beneath the concrete. None of that air comes out of your living space.
The system actually creates a small negative pressure under the slab that reverses the natural flow of soil gas into the home. Indoor air movement does not change. Indoor temperature does not change. Indoor humidity in the basement often goes down a little because the system also pulls humid soil air out as it pulls radon out.
Power use and operating cost
A typical inline radon fan draws 50 to 90 watts. The bigger fans we use on stubborn houses or large slabs might pull 110 to 150 watts. At Rochester Public Utilities electric rates, that works out to:
- Small fan (50 W): roughly $5 to $6 per month, $60 to $75 per year.
- Standard fan (90 W): roughly $10 to $12 per month, $120 to $145 per year.
- Larger fan (150 W): roughly $16 to $20 per month, $200 to $240 per year.
The fan runs continuously, so the monthly number is real and recurring. It is the closest thing the system has to an ongoing cost.
What changes the answer
- Where the fan is mounted. Exterior wall mount is the quietest from inside the house. Attic mount is slightly louder but cleaner-looking from the curb. Interior fan placement is rare, code-restricted, and not something we do.
- Pipe routing. A pipe that runs through a finished ceiling cavity can transmit some sound. We route around bedrooms wherever possible.
- Fan size. A bigger fan moves more air and runs a little louder. We size the fan to the home and the slab. Bigger is not always better.
- Age of the system. Bearings on an inline fan last about 8 to 12 years. An aging fan can start to whine before it fails. That is a normal swap, not a problem with the design.
Sources
- AARST/ANSI standards SGM-SF and RMS-MF (residential radon mitigation).
- Manufacturer specifications for Fantech RN, RadonAway RP, and AMG IF series inline radon fans.
- Rochester Public Utilities residential electric rate schedules.