Types of Radon Mitigation Systems
Radon Mitigation Systems are Soil Depressurization Systems. Radon systems come in several forms and are customized for each unique situation.
Exterior Installed Radon Mitigation Systems:
When a radon system is installed on on the exterior of a home or building, the pressurized components of the radon system are located outside while the interior components are under suction. The radon fan is usually installed at knee level opposite of the rim joist. From the fan, the radon vent stack rises above the eave of the home or building. Code states that the vent stack opening must be greater than ten feet from the ground and above the eave. The vent stack opening must also be further than ten feet from a window, door or opening that is not at least two feet below it. The vent stack should rise vertically to exhaust the radon into the atmosphere and prevent re-entrainment. More exterior radon system info....
Attic Installed Radon Mitigation Systems:
Radon Systems installed through the attic space will hide the radon system from view and offer better protection from the freezing and thaw cycle outdoors. In most situations the attic installed radon mitigation system is routed through the garage to the attic space above it. If the garage attic option is unavailable the pipes can, in some cases, be routed through multiple closets or utility chases to rise to the attic space above the home. According to code, the radon fan should always be installed a well ventilated attic space or the exterior of the home. More attic radon system info...
Passive Radon Mitigation Systems:
Radon resistant new construction techniques can be used to prevent radon gas entry in new construction homes or buildings. Most radon resistant designs consist of a gas permeable layer of gravel under the concrete slab, a soil gas collection pipe buried within the gravel layer, a suction pipe that extends through and interior wall and the exhaust point above the roof of the home. A correctly installed passive radon mitigation system should also include the sealing of cracks and sumps in the concrete slabs and foundation. The passive radon systems work by creating a vacuum through natural stack effect in the suction pipes and can be converted to active radon systems by installing a radon vent fan. More passive radon system info...
Radon Mitigation for Crawlspaces:
Crawlspaces can be major radon entry point locations. Radon gas can enter the livable areas above crawlspaces through the floorboards. To properly prevent this radon entry a crawlspace should be sealed using a durable vapor barrier that is sealed air-tight. We at RadoVent® use higher quality plastics and a method of sealing that will help prevent radon entry from the crawlspace. Our radon vapor barriers, when combined with a radon mitigation system will stop radon gas, reduce musty odors and make your crawlspace a cleaner environment for storing items. More crawlspace radon mitigation info...
HOW DO RADON MITIGATION SYSTEMS WORK?
It's called Active Soil Depressurization:
In existing homes or buildings with radon problems, active soil depressurization systems (ASD) are installed to block radon gas. ASD systems vent radon gas by creating a vacuum in the soil below the foundation. A active radon vent fan is installed to create a permanent and consistent negative pressure within the system. The negative pressure draws the radon gas to the suction point(s) where it is sucked through the radon system and vented to a safe elevation above the home or building.
Sub-Slab Depressurization is the means of pulling the radon gas and other soil gas from the soil below a concrete slab. A hole is cored through the concrete slab to reach the soil below it. A radon gas collection chamber is created by removing soil from this area to create greater surface area to suck out the radon gas. Radon suction pipes are installed in the collection chamber and continue to the radon vent fan.
Draintile Depressurization is the means of pulling the radon gas and other soil gas by creating a vacuum within the existing draintile network of a sump or drainage system. This method allows the radon mitigation system to more easily communicate with the soil surrounding the drain-tile system.
Sub-membrane Depressurization is the means of pulling the radon gas and other soil gas from below a vapor barrier. In homes and buildings with exposed dirt or gravel crawlspaces, an air-tight vapor barrier is installed and the radon suction pipes create a vacuum under this membrane.
Block Wall Depressurization is the means of pulling the radon out by depressurizing the hollow voids within a block wall foundation.