View all text of Subpart C [§ 77.200 - § 77.217]
§ 77.212 - Draw-off tunnel ventilation fans; installation.
When fans are used to ventilate draw-off tunnels the fans shall be:
(a) Installed on the surface;
(b) Installed in fireproof housings and connected to the tunnel openings with fireproof air ducts; and,
(c) Offset from the tunnel opening.