Radon is a naturally occurring gas with levels in the atmosphere which go up and down. It commonly gets into homes by seeping out of surrounding soil. However, there is evidence that links high levels of radon gas to a variety of health issues, such as lung cancer. Many people are concerned with the results of a radon test when buying or selling a home. However, these tests can be quite inaccurate and results can be manipulated in a variety of ways.

Radon Monitoring System in House Basement
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How to Fool a Radon Detector

What Is a Radon Test?

A radon gas test consists of an activated charcoal or electret ion device typically. This is left in the lowest room of a home that is in regular use. After a few days, usually between two and 10, the device can be mailed off for radon results. There are also continual radon tests, which can be done with a plugin radon detector. This gives a running average of radon levels in the atmosphere day to day. Some companies offer more instantaneous radon readings, but these can be more inaccurate than a reading taken over a period of time.

Will Open Windows Affect a Radon Test?

There are a variety of ways to "fool" a radon detector into passing a home inspection. Opening the windows of the room being tested will usually allow some of the radon to get out and dilute the actual atmosphere of the room with "fresh" air from outside. In this way, radon inspections can be tricked into giving a better reading.

What Can Fool a Radon Inspection?

On top of opening the windows, there are other methods that can trick a radon reading. Opening the door of the room, particularly if it's a basement, will allow trapped radon gas to escape. Circulation is key for passing a radon test, so fan systems or air vents can also affect the result.

Radon tests also tend to come back with lower results after a heavy rainfall or when the ground is frozen, as less radon can seep out of the soil and enter the atmosphere. By planning a radon test around these times, people can ensure a better test result.

For those trying to sell a home, there can be a temptation to try to cheat a radon test in order to make a quicker sale or sell at a higher price. If you're buying a home and are concerned about radon levels, ask if you can perform an independent radon test to gather your own results, which are less likely to be a false positive.