Why is my radon fan so noisy?

Have you wondered why your radon fan is so loud?  There are quite a few possibilities for that, which I’ll explain here, starting with the most common culprit: age.

First, how old is your system?  When did you last perform a radon test?  The US EPA recommends all US homes be tested at least once every five years.  Homes with existing mitigation systems should actually be tested more often: once every two years.  If you read my article on maintaining your radon system, you’ll know that radon testing is the number one maintenance task.

All the radon fans we sell have five-year warranties.  Actual radon fans typically last eight years on average.  I say “actual” because if you search “radon fan” on Amazon you’ll be confronted with many, many duct fans that are not moisture rated and even some fans made for gaming computers–WTF??  Give your money to a local charity before buying one of these because then it’ll at least do some good.  

Actual radon fans have higher moisture resistance than a traditional inline duct fan–this comes into play with noise later.  Soil gas is very high in moisture content.  Experts have estimated that a radon fan can move up to 15 gallons of water vapor per day!  Many homeowners note musty basement smells leaving and sump pump wells sitting barren after a radon system is installed.  Cheap fans will short out and die within weeks in these grueling conditions, which is why a $40 savings online is really just a timebomb for your health.


High suction radon fan with low durometer couplers

Radon fan motors have self-lubricating bearings, which is why it’s recommended you never turn them off, even in vacation homes.  If you turn your fan on and off, rainwater and soil vapor will rust out the bearings far faster than eight years.  I’ve seen radon fans last over two and a half decades when run continuously.  When the bearings start to fail, you often hear a high-pitched whine.  Homeowners–and neighbors–notice it immediately.  A loud whine is a clear indication that your fan is in need of replacement.  Since radon fans are sealed, repair is not cost effective.  You have to destroy the housing to get to the motor.  Once inside 90% of the fan’s moving parts usually need replacement.  Some in the industry hope to build repairable radon fans, but none have hit the market yet.

If high-pitched whir isn’t the noise you’re hearing, then perhaps it’s an over-sized radon fan.  If you’ve read my articles on fan sizing, you’ll know that “poking and hoping” is the norm and that most radon fans in America are oversized due to market pressure on contractors to be in-and-out quickly and cheaply.  Oftentimes a loud radon fan is just a fan that’s way too big for the home (Imagine if you knew nothing about cars and a salesman sold you a 2500 RAM Diesel truck just to go buy groceries with–you’d probably complain about the noise too!).  Ask a licensed radon mitigator to come perform PFE testing and efficiently size your fan.

Is your radon fan keeping you awake at night?  Poor radon system design can lead to fan vibrations reverberating throughout your home and making it difficult to sleep.  A radon fan that can be heard indoors is typically the result of pipe vibrations.  Can you move the fan to a different side of the home?  Licensed pros often try to avoid bedroom areas for this reason.  Have you installed noise reducing couplers?

These couplers isolate vibrations from the rest of the home and can lower interior noise levels dramatically.

As you can see, there are many factors at play when it comes to radon fan noise.  The best way to ensure your system is quiet and working is to use a licensed radon professional.  Don’t assume just because they’re licensed that they know how to size a fan.  Check Google reviews, look at photos and ask questions like: “Do you perform PFE testing?” “What steps do you take to size the fan properly?”.  These questions will quickly weed out the inexperienced pros and get you closer to the service you want.