Some of the following guidelines are condensed from the most recent U.S. EPA radon testing protocols.
You may want to do more than one test if:
- Your home’s foundation is over 2,000 square feet
- You have a basement and a crawl space – test in the basement and in the room above the crawl space
- Your home is a 4 level split – test each floor that is in contact with the ground
You may use this test during any season, as long as closed building conditions can be maintained. All external doors, windows, and vents should be kept closed for 12 hours before starting the test until the end of the test. You don’t need to change your normal entry and exit routines, just make sure you close the door behind you. If the building has a permanently installed radon mitigation system, air to air heat exchanger, and/or combustion air supplies for furnaces, etc., they should be operated normally. However, do not operate any whole house or window fans during the test. This test should not be started if severe weather is predicted. For example, a major storm system with winds exceeding 30 miles per hour.
We recommend starting the test on a Thursday and ending/ mailing the test back to the lab on a Monday. This allows for a 4 day test, which is ideal. If you mail it on a Monday, the kit will typically be processed by Friday and not sitting in the mail or at the lab over the weekend. The faster the kit gets to the lab, the more accurate the results will be.
This sampler is designed to be exposed 72 to 168 hours (three to seven days). This means you must leave it in place for at least 3 days. You may expose it up to 7 days if you are not testing in a humid environment (over 55% relative humidity). Either way, your test result will be an average of approximately the last 4 days of the exposure period.
Test the lowest area of the building that is used on a regular basis. This is especially important if only one test is being conducted, or if this is a follow-up test to confirm the need to mitigate for radon. Place it where it will not be disturbed. The preferred method is to hang the kit centrally in the room. Use one sampler for every 2000 square feet of floor space being tested. It should be within the normal breathing zone (2 to 6 feet from the floor). The test may be hung from an interior, non-masonry wall as long as the opening is not blocked (at least 4 inches clearance) and it is facing toward an open area of the room. String may be useful to hang the kit from the ceiling or light fixture. DO NOT place it in a draft. Keep it 3 feet or more from doorways, hallways, windows, exterior walls, and heating or air-conditioning vents. Do not place it in the same room with any type of operating fan or blower. Air blowing on or near an activated charcoal sampler may increase its sensitivity to radon. DO NOT place it near any heat source such as a stove, fireplace, or baseboard heater. Keep it out of direct sunlight. Heat may reduce the sensitivity of some radon measurement devices. DO NOT test areas of high humidity, such as bathrooms, kitchens, laundry rooms, closets, or damp basements. If you must test a damp or humid room (over 55% RH), then test only for the shortest recommended period. Moisture may reduce the sensitivity of some radon measurement devices. DO NOT place this sampler within 3 feet of another activated charcoal device. (Exception: you may place two of the same type and model of test device within 12 inches of each other when conducting a Quality Control audit or when testing for a real estate transaction).
A short note from the Airchek’s director: Our laboratory has processed over two million radon tests and we have seen almost everything that can happen to a radon test sample. We have thousands of nonreturnable test results stored in our computer, because of missing or unreadable information. Send the sample to the lab A.S.A.P. Radon does not last forever. If the sampler takes more than a week to get to our lab your test result will not be as accurate as one that arrived within three or four days. Over 8 days to get to our lab and you get only an estimated result. Over 11 days, no result can be provided.
Test results can be expected within 4 days of the lab receiving your test kit.