RMS-LB 2018 with 12/20 Revisions

ASD (revised 12/20) 29 ANSI/AARST RMS-LB 2018 (with 1220 revisions) Radon Mitigation Standards for Schools and Large Buildings 6.5.2 Safe locations required To circumvent accidents that can result in systems leaking radon and soil gas into occupied spaces due to a failed pipe joint or other sealed connection: a) ASD fans shall not be installed in the conditioned (heated/cooled) or otherwise occupiable space of a building; and b) ASD fans shall not be installed in any location directly beneath the conditioned or otherwise occupiable space of a building, such as a fan installation within a basement, crawl space or enclosed garage beneath occupiable space. 6.5.3 Approved locations Where compliant with requirements in Section 6.5.2 : a) ASD fans are to be installed in attics, on the exteriors of buildings, or in garages that are not beneath conditioned or otherwise occupiable spaces. Note—Ventilated attics or the exterior of the building are preferred locations. Considerations also include locations that avoid objectionable noise from fan vibration and exhaust air; and b) ASD fans shall not be installed below ground. Exception: Locations that are created or exist below grade that are not beneath conditioned or otherwise occupiable space of a building, such as outside the building shall be permitted if configured to protect the fan and electrical components from damage and degradation. Such locations or any enclosures created shall include reasonable access for maintenance and adequate groundwater control such as drainage and, as applicable, sump pump systems. As applicable, all electrical components, including wiring and service switch configurations, shall be rated for use in wet or damp environments. 6.5.4 Fan Installation Installation of ASD fans shall comply with the following requirements: a) ASD fans shall be sized to provide the pressure difference and airflow capacity necessary to achieve the mitigation goals; b) ASD fans shall be installed in a configuration that avoids condensation buildup in the fan housing. To achieve this requirement, ASD fans shall be installed on vertical runs of ASD piping or in accordance with the manufacturer’s specifications; c) ASD fans shall be mounted to piping using flexible couplings that comply with ASTM D5926 or ASTM C1173 or using an alternative method specified by the manufacturer that achieves a watertight connection; and d) ASD fans subject to extreme climate conditions shall be protected with thermal insulation, as needed, in accordance with Section 6.2.10.