Radon Mitigation Effectiveness
Radon Mitigation Effectiveness
Radon is the second leading cause of lung cancer next to cigarette smoking. The US Surgeon General and the Environmental Protection Agency (EPA) recommend testing for radon and reducing the high levels of the harmful substance found in homes and buildings. Authorities recommend radon mitigation if the radon level in your home or building is confirmed to be 4 picocuries per liter (pCi/L) or higher. Although radon levels that are less than 4 pCi/L still pose a risk, they can still be reduced to ensure air quality in your premises. Therefore, if your home has not been tested for radon, then you should do so immediately. If elevated levels are found in your home, then radon mitigation should be performed to keep your premises safe.
Radon Mitigation Techniques and Their Effectiveness
When radon levels reach the abovementioned threshold or higher, then radon mitigation techniques must be adopted. There are different methods for reducing the amounts of radon levels in homes or building. They are the following.
Passive Mitigation Systems
This method involves the use of radon-resistant new construction materials and techniques that can be employed to prevent radon gas entry in new construction homes or buildings. Radon-resistant designs involve a layer of gravel that is gas-permeable found under the concrete slab and a pipe for gas collection buried in the soil within the gravel layer. A suction pipe is then extended through the interior wall and an exhaust on the roof of the home. The system also involves the sealing of cracks and sumps in the concrete slabs and foundation. What this does is that it directs the flow of radon from the soil to the pipe and through the roof and away from the internal structure of a home. Therefore, its effectiveness depends on the quality of the installation of the mitigation system.
This system involves sucking the radon gas from the soil below a concrete slab. First, a hole is made through the concrete slab to reach the soil below it. Second, a radon gas collection chamber is made by removing the soil from this area to produce a wider surface area to depressurize the soil from radon gas. Radon suction pipes are installed in the collection chamber and extend to the radon vent fan. In effect, radon is pulled from beneath the house and is vented outside. Generally, indoor radon can be mitigated by sub-slab depressurization and by exhausting such radon-filled air to the outdoors, away from windows and other building openings.
The use of sub-slab depressurization to mitigate homes with elevated radon gas levels is well established. Performance data in the radon literature indicate that this mitigation process is typically able to reduce radon concentrations by 90% to 95% or from 40 pCi/L or 80 pCi/L to 4 pCi/L, respectively.
This mitigation process involves suctioning the radon gas by creating a vacuum within the existing draintile network of a sump or drainage system. This technique allows the radon mitigation system to be more easily adaptable to the soil surrounding the drain-tile system. In addition, this method can work with either partial or complete drain tile loops and offers 50% to 99% radon reduction effectiveness.
This radon mitigation method is similar to the sub-slab system, but it is used in structures with crawlspaces, where no slab or a partial slab exists. A gas-impermeable vapor barrier or membrane is installed under the floor or directly on the soil, and one or more suction pits are set underneath the membrane. Similar to the sub-slab system, sub-membrane depressurization creates a negative pressure under the building so vapors do not get sucked up into the building with lower pressures than the subsurface. It also results in less heat loss than natural ventilation in cold winter climates. It has a radon reduction effectiveness of 50% to 90%.
Other Radon Mitigation Techniques
Other methods used for radon mitigation include block wall depressurization, which depressurizes the hollow parts in block walls, and heat recovery ventilation (HRV), whose effectiveness depends on the radon concentration or the amount of ventilation air available for dilution by the method. HRV is best applied in areas with limited spaces areas such as basements. Natural ventilation and home or basement pressurization are other techniques for radon mitigation. There are also radon mitigation methods in water sources such as aeration and GAC (Granular Activated Carbon).
Reliable Radon Inspection Services
Radon is deadly if not treated. Therefore, if you require radon inspection services, then Callaway and Associates, Inc. is a company that can help. Once we find elevated radon levels in your premises, we recommend the best method from the abovementioned techniques so that normal air conditions can return to your home or place of business.
Get in touch with us today for more information about our services.