Radon Systems in a Fargo Winter

Why winter is radon season

In cold weather, the furnace heats the house and warm air rises and leaks out near the top. That pulls replacement air in low down, including soil gas through the basement floor, the sump and any gaps. This stack effect, plus windows staying shut for months, is why Fargo-area radon readings are often highest in winter. It's also why winter is a good time to test: the result shows close to a worst case.

Condensation inside the pipe

Soil gas under a slab is damp and relatively warm. As it rises through the pipe into a cold attic or outside air, moisture condenses on the inside of the pipe. A well-designed system:

• slopes all horizontal runs back toward the suction point, so water drains under the slab instead of pooling,
• keeps the fan above any low spots where water could collect,
• may include a condensate bypass at the fan in some designs.

A gurgling sound or water dripping near the fan means the pipe isn't draining properly. Call your installer.

Frost at the exhaust

When moist air leaves the top of the pipe on a very cold day, frost and ice can form around the opening. In most systems, airflow keeps the opening clear. Problems happen when ice builds up enough to narrow the outlet, or when ice forms and then falls onto a walkway or deck. Installers reduce this by:

• routing the pipe inside the house or garage and exhausting through the roof rather than up an outside wall,
• insulating any exterior section,
• using a larger pipe diameter on exterior runs,
• keeping the exhaust away from doors, walkways and eaves.

Where the fan should go

Radon fans must be outside the living space: in an attic, a garage attic, or outdoors. In this climate, attic and garage-attic locations shelter the fan and keep most of the pipe in warmer space. Exterior fans work if rated for the conditions, but the exterior pipe is the part most likely to freeze.

Winter checks for homeowners

• After a deep cold snap, look at the manometer. Liquid levels that have gone flat, or a reading far above normal, can signal a blockage or a stopped fan.
• From the ground, check that the exhaust isn't capped with ice.
• Never cover the exhaust or wrap the fan in anything that blocks airflow.
• If you lose power, the system stops. It will restart on its own when power returns.

Does a radon system make my house colder?

A sub-slab system pulls soil gas from under the floor, not air from your rooms, so its effect on heating is usually small. Sealing the sump and floor cracks can even reduce drafts. Crawl space systems with a sealed membrane can make floors above feel warmer by covering damp soil.

Want a system designed for our winters? Request a quote and ask the installer to explain their cold-weather details.

Common questions