Noise Is Not Your Friend

Posted by Erika Carroll on
What a homeowner had to do to make our competitor's system quieter

So, you thought all radon systems are quiet? Take a look at what one homeowner had to do to try to fix the excessive noise that was coming from one of our competitor’s systems.

This system was so loud, it could be heard inside the house, making the homeowner wrap the fan up as seen in the photo. We were called after the installer of the system could not fix the issue.

The following items are what is wrong with this system:

  1. Metal downspout is used as the exhaust. PVC pipe as the exterior exhaust will always be the quietest system.
  2. Exhaust is attached to the house using minimum standards. The fastener that supports the pipe on the house should be insulated with rubber.
  3. The suction point is located too close to the groundwater sump pit. This creates a potential scenario where too much air gets introduced into the system via exterior drain tiles. Extra, unnecessary air creates more noise.

There are two noises that are generated by the radon system: air flow and vibration. To minimize the noise, the following must be taken into consideration:

  • The amount of CFM (cubic feet of air per minute)
  • The size of the pipe determines how much airflow can be pushed through the system. The best standard would that the air velocity should not be greater than 700 FPM (feet per minute).
  • Excessive noise and back pressure is created when too much air is moved through the pipe. According to the best standard, a 3” pipe should move no more than 34 CFM before the system is too noisy and loses efficiency. A 4” pipe should move no more than 61 CFM, before it too becomes too noisy. The proper sizing of the pipe is important to avoid excessive noise and reduced radon reduction.

Two ways to reduce vibration transfer back to the building is the install a total of four anti-vibration reducing rubber couplings instead of only two. Also, wrap each fastener that supports the exhaust with rubber to reduce the amount of vibration transfer back to the building.

Cleaning the fan blades will also help to keep the fan balanced so that increase vibration does not occur. This should be performed by a licensed radon professional.

The takeaway: Larger diameter pipe and a carefully installed system is best for a good night’s sleep!