Radon sump and pump systems work to reduce indoor radon levels to the lowest amounts that are reasonably achievable. There is no safe amount of radon gas because long-term exposure causes a potential risk to your respiratory health. The best way to know if you have a radon problem is to test your home as it is an odorless and colorless gas that can’t be detected by the human eye. Radon mitigation systems work by extracting air from the soil underneath your home’s foundation before venting it outside to minimize radon exposure inside your home. In today’s article, we will be sharing with you the process of how to design and install radon sump and pump systems.
How Radon sumps and pumps are designed
A radon sump refers to a cavity or an underfloor space where you insert the pipe used to extract radon. The sump can be set up inside or outside by digging a hole in an exterior wall that can fit a 110 mm pipe in a space below the floor slab. The entire mitigation system is designed with a radon fan, a U-tube manometer, an active notification monitor, and a suction pit.
The radon fan can be positioned in an unconditioned space like the garage, attic, or outside your home. A U-tube manometer is a useful device that signals the radon fan is working efficiently. The active notification monitor is meant to create an alarm if your radon fan isn’t working correctly. The suction pit refers to a carved-out space dug below the basement slab floor. It is where the radon pipe is connected to extract radon from the soil beneath your home’s foundation.
- Externally constructed radon sump and pump
First, you need to check whether the ground floor construction of your home is suspended timber with a concrete capping to the soil or only made up of solid concrete. A single radon sump and pump can cover a radius of up to 9 meters around the sump. However, it can cover more than a 15-meter radius if the subsoil is permeable. You must install the sump and pump in a location that is far away from drains, windows, doors, and ventilation grills.
Drill a hole through the external wall that is 120 mm wide just below the floor slab. Create a sump by excavating the soil or a bucketful of material under the floor slab. Install a 110mm diameter pipe into the sump before you seal it to minimize air suction from within the wall. If you are mounting the fan or pump vertically, then use a short-length vertical pipe with a short radius bend of about 87.5 degrees. Use a rubber reducer coupling to install an in-line centrifugal duct from the sump to the pipe. Use a bracket fixed back to support the fan to the building. Wire the fan inside the house to a fused spur and seal the joint between the wall and floor close to the sump to reduce air suction from the room.
- Internally constructed radon sump and pump
The location where you install a radon sump and pump from inside the house should be far away from drains, preferably in the corner of a room. To create a sump, you need to drill a hole through the basement or underground floor that is about 120 mm wide and remove a bucketful of material under the floor slab. Install a short piece of 110mm pipe to the concrete floor slab to minimize air suction from the house. The pipe should continue to run into the roof space and out of the house. Use a rubber reducer coupling to connect an in-line centrifugal duct fan to the pipe.
Use a bracket fixed back to support the fan to the building. Another rubber reducer coupling can be attached on top of the fan before the pipework can be extended further through the roof. The pipe needs to be sealed properly where it exits the roof. Lastly, wire the fan back inside the house to a fused spur. The main benefit of installing a radon sump and pump internally is that you can direct it to extract radon from the center of the house. The only downside to doing this is that it can cause more disruption during installation.
Most houses only require a single pump installation to minimize the risk of radon exposure as it covers a radius of about 9 to 15 meters around the sump. However, older or larger houses may need more than one sump to cover a wider area. Installing a radon sump and pump helps keep you and your family safe by minimizing radon exposure inside your home.