RMS-LB 2018 with 12/20 Revisions

Building Investigations Prior to Design 10 ANSI/AARST RMS-LB 2018 (with 1220 revisions) Radon Mitigation Standards for Schools and Large Buildings b) Clear characterization of a radon hazard Identify testing periods that reasonably represent when the operating conditions are most likely to emphasize a clear characterization of a radon hazard. This would primarily include time periods when the difference between indoor and outdoor temperatures cause: 1. some degree of regularity in the activity of heating or cooling system blowers. This blower activity can cause negative pressure within the building; and/or 2. some degree of regularity for natural negative air pressure inside the building as compared to outside of the building (e.g. stack effect). Temporary conditions that inhibit clear characterization of a radon hazard include periods when the volume of outdoor air introduced into the building exceeds the amounts required to maintain occupant comfort and health. 5.4.8 Evaluation for design capacity For estimating mitigation design needs, compare available test data (e.g., indoor air measurements and diagnostic testing) to: a) the normal occupied operating condition for each unique sector of the building; and b) the operating conditions that are most likely to emphasize a clear characterization of a radon hazard. Informative advisory —The evaluation should comply with Table 5.4.7. It is recommended that a written evaluation of testing conditions as compared to significantly occupied conditions be available for proposals, planning and subsequent to testing. This information will aid evaluation of existing test data relative to capacity needs when designing the mitigation system(s) and for planning post- mitigation testing. 5.4.9 Investigative actions Informative advisory —The contractor should take investigative actions if, in the contractor’s judgment, the visual inspection cannot sufficiently gauge the relative magnitude of forces that could enhance or inhibit the success of a mitigation system design, to include: a) Extreme Pressures Extreme pressure differentials can exist due to: 1. tall height or large size of the building; 2. large air handlers or multiple midsized air handlers, including conditions of disrepair, that could result in the capacity to induce significant air pressure differentials; 3. large or multiple exhaust fans and 4. large boiler systems or other component capable of generating large volumes of heat. Note—Investigative actions can include measurements to identify pressure differences between the inside and outside of the building shell or between rooms. Investigative actions also might include asking from the client if documentation exists regarding pressure and airflow measurements. b) Severely Inadequate Ventilation Inadequate ventilation can exist due to: 1. design, disrepair or operation of outdoor air intake ducts; or 2. balance, design, disrepair or operation of internal air ducting and vent systems. Informative Table 5.4.7 Evaluation of testing conditions compared to “Normal Occupied Operating Conditions” (See Companion Guidance Appendix E ) Building Operating Conditions To Report: Report 1.a Operating conditions that represent the greatest amount of significantly occupied time A technical description 1.b If the building operating condition represents the greatest amount of significantly occupied time “Yes” or “No” description 2.a Operating conditions that emphasize when clear characterization of radon hazard is most likely A technical description 2.b If operating conditions emphasize when clear characterization of radon hazard is most likely “Yes” or “No” description 3. Any additional considerations Optional 4. Descriptions of conditions and possible effects that might warrant repeating the test and recommended timetable for repeating the test Conditions and recommended retest timing.