Reznor UDBP Option - Installation - Power Venting - Manual (Page 4)

Form I-UD-V-PV, Page 4
Residential Installation
Only Model UDAP Sizes 30, 45, 60, 75, 100, 125
TABLE 3 - Horizontal Vent
Terminal Clearances
A Reznor ® Option CC1 vent cap is
required. Maintain a clearance of 6 to
12 inches (152-305mm) from the wall
to the vent terminal cap for stability
under wind conditions.
Products of combustion can cause
discoloration of some building
finishes and deterioration of
masonry materials. Applying a clear
silicone sealant that is normally
used to protect concrete driveways
can protect masonry materials. If
discoloration is an esthetic problem,
relocate the vent or install a vertical
vent.
2.7 Vent Terminal
(Type of Pipe
and Vent Cap)
The vent terminal pipe must be UL Std1738 approved Category III vent pipe. Terminate
the vent with a Reznor ® Option CC1 vent cap. A different style vent cap could cause
nuisance problems or unsafe conditions. The vent cap must be the same size as the
vent pipe.
See
TABLE 3 and FIGURE 1 for requirements of a horizontal vent terminal. See FIG-
URE 2, for requirements of vertical vent termination.
Structure
Minimum Clearances for Vent
Termination Location (all
directions unless specified)
Forced air inlet within 10 ft (3.1M) 3 ft (0.9M) above
Combustion air inlet of another
appliance
6 ft (1.8M)
Door, window, or gravity air inlet
(any building opening)
4 ft (1.2M) horizontally
4 ft (1.2M) below
1 ft (305mm) above
Electric meter, gas meter*, gas
regulator*,
U.S. - 4 ft (1.2M) horizontally
Gas regulator * U.S. - 3 ft (0.9M)
Adjoining building or parapet 6 ft (1.8M)
Adjacent public walkways 7 ft (2.1M) above
Grade (ground level) 1 ft (305mm) above**
*Do not terminate the vent directly above a gas meter or service
regulator.
** Consider local snow depth conditions. The vent must be at least 6”
(152mm) higher than anticipated snow depth.
On units with long vent runs (over 50% of maximum vent length allowed) or
installed in low ambient conditions (below 50°F), it is recommended that vent
pipes be fitted with a tee, a drip leg, and a clean out cap to prevent any moisture
in the vent pipe from entering the unit. The drip leg should be inspected and
cleaned out periodically during the heating season.
Any length of single-wall vent pipe exposed to cold air or run through an unheated area
or an area with an ambient temperature of 50°F or less, must be insulated along its
entire length with a minimum of 1/2” foil-faced fiberglass, 1-1/2# density insulation.
On horizontal vent runs, the flue pipe must be pitched down toward the terminal
end 1/4” per foot for condensate drainage. Slope applies to the entire length of the
horizontal vent run. Failure to pitch the vent run properly may damage the heater due
to condensate running back into the unit.
CAUTION: Exceeding the specified vent pipe diameter and
length may result in condensate forming in the vent pipe.
2.6 Condensation
2.0 Venting Requirements and Instructions - Residential Installation (cont’d)
Support horizontal runs every six feet (1.8M). Support vertical runs of Category III vent
pipe in accordance with the requirements of the pipe manufacturer.
Do not rely on the heater for support of either horizontal or vertical pipes. Use non-
combustible supports on vent pipe.
2.5 Vent System
Support