Below are some of mitigation system pictures some from systems I have installed, and some from the web. All the systems we install (and any good radon mitigation system for that matter), will incorporate proper design, skilled installation and use high quality materials, this combination makes for a safe, long lasting and efficient system that requires almost no maintenance. Aesthetics are also important, including where the system is located and how the pipes are installed.
Some Typical Radon Mitigation Systems
This picture at the right is of a typical exterior mounted radon fan with the vent pipe terminating just above the roof line. The size of this radon fan is a little larger than average, the vent pipe is 4 inch. This installation used white rubber couplings at top and bottom of fan to attach to the vent pipe. This exterior mounted radon mitigation system could have been painted to match the house. The two smaller 2 inch PVC pipes near the radon fan are vents for the furnace and not part of the radon system.
Pictured left is another exterior mounted radon fan with the vent pipe extending above the roof line. This installation used black rubber coupling to attach the fan. Most contractors use black rubber couplings because the white ones must be special ordered.
This is an average sized radon fan and a 4 inch vent pipe. You can see the electrical cut off and waterproof conduit for the electrical supply for the fan and two brackets securing the pipe to the wall.
When the radon system is installed on the side of a house at the gable end of the roof, it is common to have a small jut out near the roof. When the pipe is installed close to the wall it has to jut out around the soffit and rake trim to get up past the drip edge of the roof.
But in snow country, you don’t want the vent pipe to extend above a roof eve if there is a possibility of a snow slide that could break the pipe. This is even more of a concern if there is a steep roof, a metal roof and or if the vent pipe is the thin wall, weaker 20 gauge PVC pipe that most contractors use. Even with the use of heavy duty schedule 40 PVC pipe, a snow slide could easily pull or break the brackets loose causing the whole system to crash to the ground. This blue house’s radon system may survive but it would have been wise to install an additional bracket on the pipe at the roofs edge for extra support.
In this picture on the right, the house had a large overhanging soffit (about 3 feet). We suggested to go through the soffit for a better looking job verses the alternative which would have been the vent pipe going out and around the soffit and the gutter then extending above the roof line about 12 inches. Going through the soffit and roof adds about $100 to the cost of the system verses the alternative, but is well worth the cost.
Going through the soffit and roof is a tricky task, many radon contractors will not offer this option, as it requires significant amount of additional labor and skill to end up with a clean well fitting installation. I’ve heard of one local radon contractor that will not do any roof penetrations at all. It is good at least to know one’s limitations.
Left picture: This is an example of a radon vent going around the soffit, using vinyl down spout material. Aluminum or vinyl downspout material can be used for radon venting in many situations.
The more common smaller size downspouts do limit and restrict the flow of radon gas. The larger sizes can cost a bit more than PVC pipe but is available in matching trim colors.
We strive to make every installation as cosmetically acceptable as possible with in the given budget. When possible we try to install the system behind a chimney so it is not visible from the front of the house.
Here the radon fan is enclose in a shroud or cover. This cover and vent pipe material can be painted to match the color of the house and can look quite nice. But sometimes the fan cover almost looks worse than the fan by itself, especially if the color does not match. Decide for yourself, the cover is about 3 to 4 times the size of the fan so it can be more of an eye sore than the fan alone and the cost for a cover installed with system is bout $100 extra.
Here is a dirt crawl space area that has be nicely sealed with a radon barrier sheeting. Sometimes it just needs to be sealed air tight around all pillars etc. and sealed to the walls all the way around. Also if needed a suction point can be placed under the tarp and tied into a radon fan mitigation system, to suck radon away.
Some dangerous radon mitigation systems and stuff we’ve seen)
In this radon mitigation picture the radon vent is in an unsafe location right above a deck where people could be standing. Any radon vent should always be at least 10 feet above ground and never where people could be sitting or standing.
The air exhausted from this vent pipe may have extremely high radon levels many times that of what the indoor radon level was prior to system installation. Also the noisiest point of the radon system is at the termination of the vent from the turbulent air flow escaping the pipe. The higher the pipe, the quieter.
The fan in the radon mitigation picture seen on the left is mounted inside the living area of the home, specifically, in the basement. This is not safe because if the fan or any fitting inside the house:
1. develops a leak,
2. comes apart or
3. is damaged, this fan could pump extremely high levels of radon into the house.
This would cause radon gas levels to be many times higher than before the system was even installed. For that reason radon fans should not be installed in the living area of a home or any where beneath the living area. All radon fans should be installed in non-living areas, such as attics or on the exterior of the home.
If you look closely, in the photo on the left you can see black mildew growing on the wall above the vent pipe. This is due to the moist air blown on it from the pipe. The air pulled from under the basement floor by the radon fan can have high amounts of moisture (up to several gallons a day).
This vent should have either a 45 degree fitting to direct the air away from the home or it should extend above the roof line. We shortened the pipe and put a 45 degree fitting on to direct the air flow out away from the wall and soffit.
HOW THE ABOVE VENT SHOULD HAVE BEEN INSTALLED… see the radon mitigation picture on the left and notice the 45 degree angle on the top of the pipe to direct the air out away from the wall and soffit to prevent mildew, peeling paint etc.
Sometimes clients do not want the pipe to go all the way up a large high wall. Since there were no windows above and none within 10 feet to the sides, this is an acceptable application.
It looks better than extending up around the soffit. It will also make it much easier to service, to change the fan at a future date, with a shorter, lighter weight pipe above the fan.
NOT SURE WHAT THIS EVEN IS?
1. Most radon fans should be mounted vertically, not sideways, otherwise the bottom portion of the fan will fill with water from condensation.
2. This fan is mounted to the duct pipe with electrical tape! (They could have at least used duct tape.)
3. They used flimsy, plastic, flexible duct pipe, totally unsuitable.
4. Worst of all, this fan is mounted in a living area of the home. Look below to the the hazard this posed to the family.
In this radon mitigation picture you can see the condition of the plastic vent that was removed from the radon fan mentioned above. This vent will not hold the radon gas very well and is not a suitable or safe vent material even if it was not torn.
The EPA and other agencies specify that the vent pipe to be used in radon mitigation systems is to be strong, PVC pipe. The same type of pipe uses for plumbing waste drains.
Here a furnace, heat duct, booster fan was used to vent radon gas using a dryer vent. This fan housing is not designed for radon and is not air tight in any way. This dryer duct material is very thin and flimsy, similar to that above. It is not safe or in any way suitable for radon mitigation. I can only surmise that it was used because it’s price was a fraction of the cost of a real radon fan, (about 1/5).
Also in this bad excuse for a radon system, the fan is open and the blades are exposed. Vermin could get in or a child could stick a hand in and result in injury.
Here is a sub-membrane suction vent. Do you see all that caulk holding it together. This installer must have run out of the proper fittings and decided to make his own rather than come back and do it right. You don’t want to see this on your job.
You can see the 2 homemade fittings on the left and the factory fitting on the right.
Here is a photo that was taken of a radon fan with ice hanging off of it. The fans can pull up to several gallons of moisture from the ground and when the air outside is cold the warm air condensates and drips back down the pipe. All the fittings and connections should be air tight, which means water tight. Here the fitting was not water or air tight and water dripped out and formed ice as if froze.
The warm air in the pipe will usually prevent or defrost most ice on the inside of the pipe.
Some of these radon mitigation pictures are illustrative of how the current radon mitigation landscape is a lot like the wild west centuries ago. Lawlessness and every man out for himself; you never know what you might come across. In the early days of radon mitigation (1980′s and early 1990′s) there were no real standards. In December 1991, EPA published “Interim Radon Mitigation Standards” as initial guidelines for evaluating the performance of radon mitigation contractors and serves as the basis for the more detailed and final Mitigation Standards that have been developed subsequently. Even today however, most states have no specific regulation or oversight for proper installation of radon mitigation systems. Hence, “Buyer be-ware”.
As with any job that needs to be done, it helps to have the right tools and experience or a knowledgeable guide and instruction to help get you through. Feel free to email me with any questions via the contact form on this site and/or feel free to purchase any of our helpful products. Over the years I have received help and instruction from many people in many places. This web site is under construction in an ongoing effort to try and put as much information and help in one place to make it easier for others looking for radon instruction, radon information or radon resources to help with all needs radon related.
For more detailed information on the proper installation of a radon mitigation system, see the EPA Radon Mitigation Standards, no longer in print. It was the basis for all of the current radon mitigation standards put out by various agencies.