CC-1000_2018

Soil Gas Control Systems ANSI/AARST CC-1000 2018 in New Construction of Buildings 9 5.7 Soil gas Inlets and airflow capacity 5.7.1 Individual inlet minimum capacity (gravel) For gravel or crushed stone classified by ASTM C33 as sizes #1 through #6, the combined total area for unobstructed openings between stones that adjoin an open void within a suction pit or perforations in perforated pipe shall be not less than twice the equivalent cross-sectional diameter of the duct pipe size applicable to the size of the plenum as specified in Section 4.3 . See Table 5.7.1 and the CC-1000 Companion Guidance for examples and calculations for meeting inlet requirements. 5.7.2 Inlets under soil gas retarders in crawl spaces The configuration shall be constructed to ensure the air transfer openings extend under all portions of the soil gas retarder(s) . In addition: a) Inlet openings shall be no less than 12 inches (30 cm) away from the sides of the plenum ; b) The combined total area of inlet openings for perforations and open ends of pipe shall be not less than twice the equivalent cross-sectional diameter of the duct pipe size applicable to the size of the plenum as specified in Table 4.3 . c) At a minimum, perforated pipe or equivalent material not less than 10 feet (3 m) in length and 3 inch (7.6 cm) nominal diameter shall be provided for each connection to trunk or branch piping. 5.7.3 Whole system minimum inlet capacity The combined total area of all unobstructed inlet air transfer openings on the face of aggregate or soil shall be not less than twice the equivalent cross-sectional pipe diameter required in Section 4.3 , “Soil gas vent systems per plenum size.” Exceptions: Inlets adjoining layers of sand, fine gravel and soils shall be in accordance with Section 5.5.3 . Void space constructed without obstruction under concrete shall have inlet openings n ot less than the equivalent size required in Table 4.3 . Table 5.7.1 Examples of minimum inlet air transfer capacity Minimum surface-face for gravel size numbers 5, 56, 57 or 6 to achieve required air transfer openings between stones. Common Examples Duct pipe size Minimum surface face of the gravel Open face of gravel for pits with a 4" (10 cm) layer gravel . Equivalent openings per length of perforated pipe Minimum for ASTM F705, F758, D2729, AASHTO 252: 1.0 in 2 /ft (21 cm 2 /m) Other product examples 3" (7.6 cm) 214 sq in (1,383 cm 2 ) = 4" x 12" diameter pit (10 cm x 30 cm) 3" x 18 ft (5.4 m) 4" (10.2 cm) 381 sq in (2,458 cm 2 ) = 4" x 16" diameter pit (10 cm x 33 cm) 4" x 32 ft (10 m) 4" x 7 ft (2.3 m) 2.0 in 2 /ft (42 cm 2 /m) 6" (15.2 cm) 857 sq in (5,531 cm 2 ) = 4" x 24" diameter pit (10 cm x 61 cm) 6" x 71 ft (22 m) 6" x 40 ft (12 m) 2.0 in 2 /ft (42 cm 2 /m) "#$%&'(!)(*+(#+,'(!-$+!.*/0,123$+,*/!