Detroit Radiant Products Company UH Series - Manual (Page 31)

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UH Series
Vent Locations and Clearances:
• Category III venting systems may NOT be common vented, and no other gas units are
allowed to be vented into it.
• Vent must terminate a minimum of 4 feet below, 4 feet horizontally from, or 1 foot above any
window or door that may be opened or gravity air inlet into the building.
• Vent must terminate a minimum of 3 feet above any forced air inlet that is located within 10
feet.
• Horizontal venting sections of the vent pipe on a Category III termination must be installed
with a downward slope from the appliance at a pitch of 1/4 inch per foot.
• The bottom of the vent terminate must be located a minimum of 12 inches above grade level
and must extend beyond any combustible overhang. Vents adjacent to public walkways
must terminate a minimum of 7 feet above grade level.
• The vent terminal must be installed to prevent blockage by snow and protect building
materials from degradation by flue gasses.
• The vent cap must be a minimum of 6 inches from the sidewall of the building.
• Vent must be a minimum of 36 inches below or extend beyond any combustible overhang.
• Vents must terminate a minimum of 3 feet from a window or door that may be opened, and a
non-mechanical air supply inlet or combustion air inlet into the building.
• Vents must terminate a minimum of 6 feet from a mechanical air supply inlet.
Never join two sections of double wall vent pipe within one horizontal vent system, as it is
impossible to verify that inner pipes are completely sealed.
Figure 3.10 • Sidewall Venting Requirements
Building **
Overhang**
Sidewall
Double-Wall
B-Vent
Single
Wall Vent
Wall Thimble
Sidewall
Vent Cap
6 in.
min.**
B to C Adapter
Heater
1/4 in. downward
pitch per foot
36 in.
min.**
3.0 Installation • Vent Locations and Clearances • Sidewall Venting Requirements
**Vent must extend beyond any combustible overhang if the vent is less than 36 in. below the combustible overhang.