Radon Control Professionals South
Why is there no Raincap on my System?
One of the things that people invaribly want to do is to put discharge on the piping system to prevent rain from falling in. Rain does not present a concern for two reasons. First the air coming out the pipe blows the rain away. Secondly, the cross section area of the pipe is only 12 square inches. Even if the rain fell straight down and the air stream did not eject it, only 1 gallon of water would be collected if your average rainfall is 20 inches per year. So there really is no need to utilize rain caps and, in fact, they could cause problems with the system.
If you put a rain cap on or install some type of rain diverter on the dicharge you will:
* Cause the exhaust gas to be blown down towards the home. This will increase the potential for the exhausted gas to re-enter the home. If this happens you will not be able to recognize it. The above figure illustrates the direction of air flow of three different discharge configurations. (Note that for the purposes of the illustration an exhaust stream is shown, in reality you cannot see the exhaust.)
* Increase the likelihood of condensate fro the system to freeze and form an ice ball on the end of the pipe, thus causing the system to malfunction.
* Decrease the operating vacuum of the fan and effect your system's ability to reduce radon.
Just put a rodent/bird screen in the end, and point it away from the home.