MALB_2014 with 1-21 Revisions

Conducting Measurements of Radon and Radon ANSI/AARST MALB-2014 with 1/21 Revisions Decay Products in Schools and Large Buildings 14 5.0 TESTING PROCEDURES AND OPTIONS 5.1 Test Deployment Periods 5.1.1 Test phase All measurement locations in each building shall be tested on the same days for: a) all locations required in Section 3 within each building; and b) all locations identified within each building for follow-up test procedures . 5.1.2 Minimum deployment periods While deployment periods should optimally collect at least 48 hours of valid sampling time, tests shall be conducted continuously for durations that are: a) not less than 46 hours under closed-building conditions that comply with Section 4 ; and b) not less than the minimum exposure time recommended by the manufacturer of the device. Note—For tests extended an additional day or more, it is best to terminate the test at a similar time of day as when the test was started to more evenly account for day-to-night fluctuations of radon entry. 5.1.3 Non-residential deployment periods Where the building or portion of the building is not significantly occupied 24 hours a day, such as a school or office building, testing shall only be conducted, in accordance with Section 5.1.2 , during portions of a week when the building is significantly occupied. Exception —Where HVAC systems are not operated differently during nights, weekends and holidays compared to when occupied by the majority of workers or students. 5.1.4 Longer test periods When longer test periods are chosen with intent to more closely evaluate the annual average radon concentration before deciding if mitigation is warranted, the test period shall include heating season conditions that are not less than the percentage of year when heating systems are active. Exception: Where heating season conditions are not the normal occupied building operating condition as defined in Normative Appendix A . 5.2 Evaluation of Occupied Versus Unoccupied Concentrations For non-residential buildings or portions of a building that are not significantly occupied day and night most the year, an evaluation of occupied versus unoccupied radon concentrations is recommended and shall be permitted as an additional line of evidence relative to mitigation decisions. When conducting such evaluation, the test devices, procedures and reporting shall comply with Normative Appendix B . 5.2.1 When to conduct the evaluation An evaluation of occupied versus unoccupied radon concentrations is permitted during initial testing, follow-up testing , post-mitigation testing, or in a series of sequential tests. An evaluation that simulates various building operating conditions is also permitted in accordance with Normative Appendix B-2 5.2.2 Where to conduct the evaluation Informative advisories: During initial testing, the evaluation is recommended for each unique sector at locations where airflow from HVAC systems is most representative of occupied rooms within the unique sector . For follow-up testing , the evaluation is recommended for at least the location of the highest radon concentration found during previous measurements within each unique sector .