035-20499-001 Rev. B (1004)
12
Unitary Products Group
VENT SYSTEM
This furnace is certified to be installed with one of two possible vent
configurations.
1.
Horizontal vent system. This vent system can be installed com-
pletely horizontal or combinations of horizontal, vertical, or offset
using elbows.
2.
Vertical vent system. This vent system can be installed completely
vertical or a combination of horizontal, vertical, or offset using
elbows.
HORIZONTAL VENT APPLICATIONS AND
TERMINATION
When selecting the location for a horizontal combustion air / vent termi-
nation, the following should be considered:
1.
Observe all clearances listed in vent clearances in these instruc-
tions.
2.
Termination should be positioned where vent vapors will not dam-
age plants or shrubs or air conditioning equipment.
3.
Termination should be located where it will not be affected by wind
gusts, light snow, airborne leaves or allow recirculation of flue
gases.
4.
Termination should be located where it will not be damaged or
exposed to flying stones, balls, etc.
5.
Termination should be positioned where vent vapors are not objec-
tionable.
6.
Horizontal portions of the vent system must slope upwards and be
supported to prevent sagging.
7.
Sealed combustion air systems must be installed so the vent and
the combustion air pipes terminate in the same atmospheric zone.
Refer to Figures 13 or 14.
VERTICAL VENT APPLICATIONS AND
TERMINATION
Roof mounted vertical terminals may be field fabricated. Standard PVC/
SRD fittings may be used. If installing a vertical venting system through
any unconditioned space such as an attic or crawl space it must be
insulated.
1.
Observe all clearances listed in vent clearances in these instruc-
tions.
2.
Termination should be positioned where vent vapors are not objec-
tionable.
3.
Termination should be located where it will not be affected by wind
gusts, light snow, or allow recirculation of flue gases.
4.
Termination should be located where it cannot be damaged,
plugged or restricted by tree limbs, leaves and branches.
5.
Horizontal portions of the vent system must slope upwards and be
supported to prevent sagging.
6.
Sealed combustion air systems must be installed so the vent and
the combustion air pipes terminate in the same atmospheric zone.
Refer to Figures 13 or 14.
VENTING MULTIPLE UNITS
Multiple units can be installed in a space or structure as either a single
pipe configuration or a two-pipe configuration.
The combustion air side of the single pipe configuration shown in Figure
19 is referred to in these instructions as ambient combustion air supply.
Follow the instructions for ambient combustion air installations, paying
particular attention to the section on air source from inside the building.
The vent for a single pipe system must be installed as specified in the
venting section of these instructions with the vent terminating as shown
in Figure 12. Each furnace must have a separate vent pipe. Under NO
circumstances can the two vent pipes be connected together.
The combustion airside of the two-pipe configuration shown in Figure
18 can be installed so the combustion air pipe terminates as described
in outdoor combustion air or ventilated combustion air sections in these
instructions. Follow the instructions for outdoor combustion air or venti-
lated combustion air and the instructions for installing the vent system
with the vent terminating as shown in Figures 15 or 16. The two-pipe
system must have a separate combustion air pipe and a separate vent
pipe for each furnace. Under NO circumstances can the two combus-
tion air or vent pipes be connected together. The combustion air and
vent pipes must terminate in the same atmospheric zone.
FIGURE 12:
Termination Configuration - 1 Pipe
FIGURE 13:
Termination Configuration - 2 Pipe
MAINTAIN 12” MINIMUM CLEARANCE
ABOVE HIGHEST ANTICIPATED SNOW
LEVEL. MAXIMUM 24” ABOVE ROOF.
12” MIN.
12” MIN.
12” VERTICAL SEPARATION
BETWEEN COMBUSTION AIR
AND VENT
MAINTAIN 12”
MINIMUM
CLEARANCE
ABOVE
HIGHEST
ANTICIPATED
SNOW LEVEL
12” MINIMUM
BELOW OVERHANG
12” SEPARATION
BETWEEN BOTTOM
OF COMBUSTION
AIR PIPE AND
BOTTOM OF VENT
MAINTAIN 12”
MINIMUM CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL OR GRADE,
WHICHEVER IS
HIGHER
FIGURE 14:
Termination Configuration - 2 Pipe Basement
12” MIN.
12” MIN.
OVERHANG
12” MINIMUM
BELOW
OVERHANG
12” SEPARATION
BETWEEN BOTTOM
OF COMBUSTION
AIR PIPE AND
BOTTOM OF VENT
MAINTAIN 12”
MINIMUM
CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL OR GRADE,
WHICHEVER IS
HIGHER
