When testing for radon it depends on the type of equipment and the test you’re performing as to determine the length of time needed to perform a NRPP compliant radon test. There are many different types of testing equipment available to the general public. The same radon testing equipment is used by professional testing facilities. Some facilities use more sophisticated equipment.
When testing a home for radon during a sales or rental transactions a standard time has been created. When testing for radon for a sales transaction the testing equipment must be deployed for a minimum of 48 hours. These tests can be extended in cases of severe weather or temperature changes or an adverse event to the property. Other reasons which would require a 48-hour test to be extended would be closed house conditions were not met.
Closed house conditions must be maintained during the entire testing period. Some common things included in the definition of closes house conditions are keeping doors and windows closed while not in use. Turning off ceiling fans or not using equipment such as window mounted air conditioning units which exchange outside with inside air. In some cased the equipment may have been moved voiding the test. There are strict regulations as to how to deploy radon testing equipment. It is best to consult a home inspector who is certified and or licensed to provide this test for a deeper understanding of restrictions and causes for extended testing.
