Are Radon Levels Higher in Winter? You’ll Want to Know

radon-winter-home

Many people are familiar with the importance of testing for radon, a gas that forms from the radioactive decay of naturally occurring uranium in soil. It is released by seeping through the soil into the atmosphere.

We can’t see, smell or taste radon, and if we don’t test for it, we can breathe it for years without being aware. Because radon is a Type A carcinogen, if it’s present in high enough concentrations for a long enough time, it can cause lung cancer.

Those of us who live or work in Oswego, Yorkville, Naperville, Aurora or Plainfield (IL) may have tested for radon more recently, or we may have done so a while ago. Either way, if we received a good result, we may have moved on and forgotten about it, not realizing that radon levels can continue to change during different seasons.

Here at Trinity, people will sometimes ask us whether radon levels are higher in winter than in summer. The answer is they often can be.

Here’s why.

The Stack (Chimney) Effect

When the snow and brittle air bear down, we seal in and bundle up. That’s good for keeping us warm, but it can also develop a radon risk.

The warmer air we generate indoors rises because it is less dense than cold air. It will then escape to the colder air outside by any means possible, such as through the top of the house, an open door or a cracked window. This creates a vacuum. To balance the air pressure, the house will need to replace the air that escaped.

The house can gain some of that air from the earth. Because many modern homes are built with airtight seals around doors and windows, the air will enter through any area that touches the soil, such as foundational concrete, protruding plumbing pipes, sump pump pits, crawlspaces and floor drains. That air can carry with it radon gas that has formed.

Trapped Radon

Radon levels can be higher in winter because of how seasonal factors can secure the gas.

Winter’s combination of precipitation and biting cold can freeze the ground. This forms a sealing layer that blocks the release of radon from the soil. Instead, the gas will concentrate more underground and potentially seek release through homes.

Our closed and sealed houses can likewise contribute to higher radon levels in winter. In summer, we’ll often open windows and doors, which helps to dilute radon gas in the air. In winter, on the other hand, we’ll keep the windows and doors tightly shut.

Like the frozen ground layer outside, an enclosed house will help radon collect instead of escape. In addition, rather than solving the issue, opening doors and windows in winter can add to the home’s stack effect by introducing more cold air to push up on warm air.

Why Testing in Winter Is Wise

Testing in winter is a good idea because in most cases we’re measuring radon’s highest potential concentration in the home. We don’t want to rest easy on a low measurement taken in summer. We do want to know how much gas is present under winter conditions that can create higher levels of radon.

This becomes all the more important when we consider we typically spend much more time indoors in winter. The good news is that even if a higher radon level is detected, it can be corrected with a properly installed radon mitigation system that is more affordable than many might think.

If you already have a radon mitigation system, winter also is a good time for a radon test simply to ensure the system is working, especially if you haven’t tested it in a few years. Mitigation systems can fail during winter because of frozen condensation in pipes, snow capping the vent stack or even a tripped GFCI outlet caused by a space heater.

Restrict Radon Gas Starting Today

Trinity Electrical and Radon Mitigation helps you ensure your home is safe from radon while you’re focused on keeping it warm. If you have questions or concerns about higher radon levels in winter, we will be glad to speak with you. Contact us at (630) 499-1492 to speak with a professional serving Oswego, Yorkville, Naperville, Aurora and Plainfield.


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