Definitions.

CFR · 2024-01-01 · US · Title 10

(1) All variations of blade pitches of an adjustable-pitch axial fan may be considered a single basic model; and (2) All variations of impeller widths and impeller diameters of a given full-width impeller and full-diameter impeller centrifugal fan may be considered a single basic model. (1) A reversible axial fan in cylindrical housing that is designed and marketed for use in ducted tunnel ventilation that will reverse operation under emergency ventilation conditions; (2) A fan for use in explosive atmospheres tested and marked according to the English version of ISO 80079-36:2016 (incorporated by reference, see § 431.173); (3) An electric-motor-driven-Positive Pressure Ventilator as defined in AMCA 240-15 (incorporated by reference, see § 431.173); (4) A fan bearing a listing for “Power Ventilators for Smoke Control Systems” in compliance with UL 705 (incorporated by reference, see § 431.173); or (5) A laboratory exhaust fan designed and marketed specifically for exhausting contaminated air vertically away from a building using a high-velocity discharge.

official document · source cfr-2024 · id 10:§ 431.172