Radon Mitigation Methods
We use several proven methods to reduce the radon levels in your home. The two most common methods are Active Soil Depressurization (ASD) and Sub-Membrane Depressurization (SMD). We will design and install a system for you based on unique factors, including foundation size, design, and soil type.
Your system includes specially designed radon fans for Active Soil Depressurization, which are both quiet and efficient. In most cases, the fan uses less power than a standard 100-watt light bulb.
We also have other methods available if neither ASD nor SMD effectively lowers your radon levels. Statistically, ASD and SMD are successful in addressing radon issues in 99% of homes in the Midwest.
Active Soil Depressurization (ASD)
Active Soil Depressurization (ASD) is the most widely used method to reduce radon levels in homes. The process begins by sealing the basement concrete floor, which involves caulking cracks, sealing the sump pump hole (if present), and filling any holes in the concrete. Next, a 3.5-inch diameter hole is drilled into the slab, and the material beneath is removed to create a suction pit. A 3-inch PVC pipe is then inserted through the slab and caulked to secure the pipe in place.
The PVC pipe is routed upwards and exhausted at least 12 inches above the roofline. A specially designed in-line fan is installed either outside the house, in the attic, or in another unconditioned space. This fan creates a slight vacuum in the suction pit below the slab, capturing radon gas before it can enter your home. The radon gas is then safely discharged into the air above the roofline, where it dissipates harmlessly.
While the PVC pipe can be routed along the exterior of the home, we typically route it through the interior using existing walls, closets, and other areas. Additionally, a U-tube manometer is installed to allow homeowners to easily monitor the system and ensure it’s functioning correctly. We also install an audible failure warning device to alert you to low system pressure.
Sub-Membrane Depressurization (SMD)
Sub-Membrane Depressurization (SMD) operates similarly to ASD but is used in areas without a slab, such as crawl spaces. In an SMD system, an airtight poly vapor barrier is placed over the area and sealed around the edges. A vacuum is then created using a specially designed in-line fan, drawing air from below the poly to create suction on the material beneath. The exhausted air is routed outside the structure, much like in an ASD system. In some cases, a combination of both systems may be used together.
Air to Air Exchangers
An air-to-air exchanger works with two fans and ducts that move air through the system, with one fan extracting radon-contaminated air from indoor areas and the other bringing in fresh air from outside.
This type of system can be used when areas are inaccessible for proper SMD installation. While this method has been proven effective, its installation cost, maintenance requirements, and energy efficiency make it less practical in most cases.