SGM-SF_2017with 12/20 Revisions

Non-ASD Methods 50 ANSI/AARST SGM-SF 2017 (with 1220 revisions) Soil Gas Mitigation Standards for Existing Homes 12.13.3 Passive soil air or indoor air dilution Foundation vents shall be non-closeable when installed specifically to increase the natural ventilation of a crawlspace or other interior space for mitigation purposes. Vents to outside air that are not associated with economizer setback systems shall be non-closeable when installed to increase the natural ventilation of a crawlspace, soil or interior spaces for mitigation purposes. Informative advisory —In areas subject to subfreezing conditions, the need to insulate, isolate or apply heat-tape to water supply and distribution pipes in the crawl space should be considered when installing foundation vents. 12.13.4 Passive mechanical systems Note—Such methods have included wind-driven turbines, solar-powered fans and piping configurations that seek to enhance the effect of wind for generating negative pressure within ASD piping. Informative advisory —A wide variety of mechanisms or configurations have been tried and studied for countering the natural energy forces that drive soil gas into a building. Such technologies have not yet demonstrated reliability for consistent and sustainable mitigation . Therefore, such technology is beyond the scope of this document.