Radon Fan Load- Does a timer make sense?

I just measured my Radon fan load, and it looks to be about 60-70W of constant energy use. That’s ~$75/yr.

I’m not overly concerned about Radon, as we had it tested when we moved into the house, and the readings were negligible. I’m sure the fan has something to do with this, but I’m questioning the need to run the thing 24/7. I live in a neighborhood where all houses got fans when they were built.

Is this something that you’d consider putting on a timer and running maybe 12 hours a day? I wouldn’t want to risk real radon exposure, but I feel the risk is minimal.

I feel like there could be a safety / functionality concern I’m missing here, but I’d like to know what it is.

In new commercial applications I install the radon fan to run when the HVAC runs.

I’m sure you could do something similar with a smart plug.


Measuring radon levels with the mitigation system active is like measuring how much it’s raining from under your umbrella. You’d need to turn the system off for an extended period of time and then take measurements. Given that radon fan timers are not commercially deployed, I’d imagine that some testing has been done to conclude that the fan needs to be running 24/7. If you were to do testing, I’d think that running the fan for 30 minutes every hour, or 5 minutes of every 10, would be a better plan than cycling at 12 hour intervals. 12 hours is a long time for radon to build up.

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I install a radon monitor in my basement and i look at sometimes, the long term number is not something which i am concerned about, i am more curious about a day or week’s averages and max, when I got the system installed the average was fine but the raw data from the monitor did show me few minutes of spike beyond 5, I think spending $75 an year is not bad when it comes with some benefits, I run dehumidifier a lot less in my basement now since a lot of moisture is driven out by the radon fan, that itself make it worth running 24/7 for me.

Good to know. I live in Denver, so humidity isn’t an issue here.