State Industries SBD85 500 - Manual (Page 5)

SBD TANK TYPE HEATERS
SERVICE HANDBOOK
Technical Training Department
Ashland City, TN ©2003
4
EXTERIOR CLEARANCE
This illustrates the exterior roof clearances for SBD units with natural draft venting. The
vent shall extend at least 3 feet above the highest point where it passes through a roof of
a building, and at least 2 feet higher than any portion of a building within a horizontal
distance of 10 feet (for vents of 12" in diameter or less). (NFPA 54 ANSI Z 223.1 SEC
7.5.2a). (Sec 7.6.2a may allow reduction to 8 feet with a “ Listed vent cap”).
"Copyright by the American Gas Association. Used by permission of the copyright holder".