Radon is a colorless, odorless gas that forms naturally in rock and soil, moving upward through the ground and entering homes through gaps in the foundation. In New York and Connecticut, local geology creates elevated radon risks in many residential areas. Routine radon testing helps homeowners evaluate gas levels in lower living spaces, and testing is the first step toward managing indoor air quality and keeping your household safe.
How Radon Enters NY and CT Homes
Radon builds up beneath concrete slabs and foundation walls. According to the U.S. Environmental Protection Agency (EPA), soil gas enters buildings through pressure differences: your home acts like a vacuum, drawing gas inside from the surrounding soil.
Common entry points for soil gas include:
- Cracks in poured concrete floors and basement walls
- Unsealed openings around sump pits
- Gaps in foundation slab joints and plumbing penetrations
- Openings around basement floor drains
Regional Soil Conditions in New York and Connecticut
Data from the New York State Department of Health and the Connecticut Department of Public Health show high radon potential across both states. Granite bedrock and glacial till in Westchester County and Fairfield County release radon gas as uranium decays. Indoor gas levels vary significantly between neighboring homes because local soil composition and foundation tightness both influence how gas moves.
Radon Testing Options and EPA Guidelines
You cannot see or smell radon gas, so accurate testing is the only way to measure its presence. Radon is measured in picocuries per liter of air (pCi/L), which quantifies radioactive decay per liter. The EPA recommends taking action to lower radon levels when test results show 4.0 pCi/L or higher, and it suggests considering mitigation if levels fall between 2.0 and 4.0 pCi/L.
Test Duration Ranges and Methods
Homeowners can choose between short-term and long-term testing methods depending on their needs:
- Short-term test (2 to 90 days): Best for quick initial screening during real estate transactions or routine spot checks.
- Long-term test (91 to 365 days): Best for measuring average year-round exposure and accounting for seasonal fluctuations.
- Continuous monitor (48 hours to ongoing): Best for tracking real-time radon fluctuations alongside changes in weather or ventilation.
Short-term tests use charcoal canisters or electret ion chambers to capture quick data, while long-term tests use alpha track detectors to record exposure over multiple seasons. Cold winter months often show higher indoor readings because homes stay more tightly sealed.
Mitigation Systems and HVAC Ventilation Effects
When radon testing reveals levels above 4.0 pCi/L, dedicated active radon mitigation is the primary solution. Active soil depressurization systems use a specialized vent pipe and fan to pull radon gas from under the foundation and vent it safely outside. General mechanical ventilation alone cannot replace a dedicated mitigation system when soil gas levels are high.
How HVAC Systems Support Overall Indoor Air Quality
While active mitigation fixes soil gas entry, balanced HVAC operation helps maintain overall indoor air quality. Pressure imbalances caused by heating or cooling equipment can affect airflow in lower living spaces. Proper air distribution, energy recovery ventilators, and clean ductwork prevent stagnant air pockets and reduce overall indoor pollutant levels.
Protect Your Home Air Quality
Regular testing helps homeowners monitor soil gas levels and maintain a healthy indoor environment. Factors like seasonal weather, soil moisture, and house settling change how gas enters a building over time, so re-testing every two years helps ensure your living space stays safe.
By combining accurate testing, active mitigation when needed, and professional indoor air quality solutions, homeowners in Westchester County and Fairfield County can maintain balanced, fresh indoor air.
Schedule an Indoor Air Quality Assessment
Sila has served homeowners in Westchester County and Fairfield County since 1989. Our experienced team helps evaluate home ventilation, inspect ductwork, and install solutions to balance indoor airflow. Contact our White Plains, NY office today to speak with a technician and request an indoor air quality assessment.