Reducing Radon in New Construction of ANSI/AARST CCAH 2020 1 & 2 Family Dwellings and Townhouses 14 SECTION 701 PROVISION FOR ACTIVE SOIL DEPRESSURIZATION (ASD) SYSTEM FAN 701.1 Available space for ASD fan. Clearance space at the location where an ASD fan could be installed shall be provided. The clearance provided shall be a cylindrical space having a diameter of not less than 21 inches [53 cm] and minimum vertical height of not less than 36 inches [91cm] that is centered on system piping. This clearance space to accommodate a fan installation shall be located in accordance with ASD fan location requirements in Sections 701.2 and 701.3. 701.2 Fan location. The clearance space provided for locating ASD fans shall be in attics, within an approved enclosure, in garages that are not beneath conditioned spaces or outdoors. 701.2.1 Fan locations prohibited. ASD fans shall not be installed below ground, in conditioned spaces, in occupiable spaces of a building or in any basement, crawl space or other interior location that is directly beneath a conditioned or occupiable space of a building. ASD fans shall not be mounted in any location where pipe positively pressured by the fan is located inside conditioned or occupiable space. 701.2.2 Fan enclosures for conditioned attics. Where an ASD fan is located in an unvented attic space, the fan shall be isolated in an enclosure that does not communicate with the rest of the attic space. The fan enclosure shall be sealed against air leakage, shall be constructed to provide access to the fan and shall be provided with one or more ventilation openings to the outdoors that have a total net free area of not less than 25 square inches (161 cm 2 ). The unconditioned fan enclosure shall meet the requirements of Sections 701.1 and 701.2. The construction of the enclosure shall meet the requirements of the applicable building and energy codes. 701.3 Fan access is to be provided. Access (limited) shall be provided for each ASD fan location to allow installation of ASD fans and replacement of same. Access entry shall be located not greater than 30 feet [9 m] from the ASD fan location. 701.4 Electrical outlet is to be provided Branch circuit conductors shall supply an outlet located within 6 feet [1.8 m] of an ASD fan location. 701.4.1 Label. The over-current device for the branch circuit supplying the ASD fan shall be labeled to indicate that it supplies the radon fan. 701.4.2 Disconnect. Where the fan is not cord and plug connected, a means of electrical disconnect shall be provided for and within sight of the ASD fan . The electrical disconnect shall be labeled as to its purpose.