MAH_2019

Protocol for Conducting Measurements of ANSI/AARST MAH 2019 Radon and Radon Decay Products in Homes 8 5.4.3 Shared heating and cooling systems Where heating and cooling systems add outdoor air ventilation to a residential building or where a single air handler distributes air to multiple dwellings, testing is to be conducted in accordance with: a) ANSI/AARST MAMF “ Protocol for Conducting Measurements of Radon and Radon Decay Products in Multifamily Buildings ” or, as applicable b) ANSI/AARST MALB “ Protocol for Conducting Measurements of Radon and Radon Decay Products in Schools and Large Buildings ” in addition to, or as otherwise required by, local statutes. Note—Section C of the attached MAH Companion Guidance provides descriptions of HVAC ventilation systems. 6.0 CONDUCTING THE TEST 6.1 Verify Compliance with Required Test Conditions 6.1.1 Where closed-building conditions cannot be maintained during the test Short-term tests are not to be conducted if closed building conditions in accordance with Section 4 cannot be maintained across the test period. 6.1.2 Where closed-building conditions did not occur prior to the test If closed-building conditions were not maintained for 12 hours prior to deployment, the radon test is to be conducted with one of the following options: a) The radon test is postponed until at least 12 hours of closed-building conditions have been maintained prior to initiating the test; or b) The test period is extended to 4 days or more after closed-building conditions are initiated; or c) The test period is extended, if testing with a continuous monitor. For this option, device features or other methods are to be employed to obtain an average reading that represents no less than 46 hours of contiguous data collected after 12 hours of closed-building conditions have been maintained. 6.1.3 Where closed-building conditions might pose a health hazard to occupants If closed conditions are observed to pose a health hazard, occupants shall not be placed in harm’s way. Informative advisory —If closed conditions are observed to pose a health hazard, radon testing should not be conducted and should be rescheduled for a time when conditions are safe. For example, hot weather can pose a health hazard for buildings that have no cooling systems. For these buildings, safe conditions may require outdoor air ventilation including window fans or evaporative cooling systems. Test results from measurements conducted when needs for seasonal comfort caused ventilation with outdoor air do not provide reliable information for deciding whether or not mitigation is needed. 6.1.4 Extenuating Circumstances Informative advisory —When temporary or unexpected conditions are encountered that might adversely influence test results, it is recommended to take action to circumvent adverse influences on the test result. Sections 8.5.4 , 8.5.5 and 8.5.9.3 include descriptions of such concerns that, if not resolvable when conducting the test, are required to be noted with test reports. For example: For homes where return air ducts from forced air heating/cooling systems are under concrete floors, a test should be conducted during a time or season when the heating/cooling system fan is operating. This is a situation where radon concentrations might be far more hazardous during months when the heating/cooling system fan is consistently active.