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RADON REDUCTION TECHNIQUES FOR EXISTING DETACHED HOUSES - TECHNICAL GUIDANCE (THIRD EDITION) FOR ACTIVE SOIL DEPRESSURIZATION SYSTEMS
HENSCHEL, D. RADON REDUCTION TECHNIQUES FOR EXISTING DETACHED HOUSES - TECHNICAL GUIDANCE (THIRD EDITION) FOR ACTIVE SOIL DEPRESSURIZATION SYSTEMS. U.S. Environmental Protection Agency, Washington, DC, EPA/625/R-93/011 (NTIS PB2000-106361), 1993.
This technical guidance document is designed to aid in the selection, design, installation and operation of indoor radon reduction techniques using soil depressurization in existing houses. Its emphasis is on active soil depressurization; i.e., on systems that use a fan to depressurize the soil. However, it also discusses active soil pressurization, where the system fan is reversed to blow outdoor air into the soil. Passive soil depressurization is also addressed, with passive systems, natural phenomena (including the indoor vs. outdoor temperatures and the flow of winds over the roofline) relied upon to provide depressurization instead of a fan. The document focuses on the retrofit of radon reduction methods into existing houses as distinguished from the incorporation of radon-resistant features into new houses during construction. The document focuses on detached houses, as distinguished from multifamily dwellings (apartments, condominiums) and from large buildings such as schools and commercial buildings. The document addresses all variations of the soil depressurization approach, including sub-slab depressurization, drain-tile depressurization, block-wall depressurization, and sub-membrane depressurization in crawl spaces. Soil depressurization techniques can treat only that radon entering the house as a component of soil gas; i.e., only where the radon problem is due to naturally occurring uranium/radium.