108.185—Ventilation for enclosed classified locations.
(a)
The ventilation system for each enclosed classified location must be designed to maintain a pressure differential between the enclosed classified location and each non-classified location adjacent to the enclosed classified location, so as to prevent the discharge of ignitable gases into the non-classified adjacent locations.
(c)
Each unit must have alarms that are powered independently of the ventilation motor power and control circuitry and sound at a continuously manned station when—
(d)
Each ventilation system for enclosed classified locations must provide a complete change of air every five minutes.
[CGD 73-251, 43 FR 56808, Dec. 4, 1978, as amended by CGD 94-108, 61 FR 28270, June 4, 1996]