W415-1007 / A / 07.18.12
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10.0 TeRMInaTIons
10.1 CoMbUsTIon aIR
HORIzONTAL -
The combustion air termination is made up of a
medium or long sweep 90° elbow pointing downward to prevent
rain from readily entering the combustion air intake piping.
If the required clearance to grade cannot be obtained with the
“straight through” configuration, the combustion air intake pipe may
be “periscoped” up to 24” to gain extra height
(Figure 9)
vERTICAL -
The combustion air termination is made up of a pair
of medium or long sweep 90° elbow pointing downward to prevent
rain from entering the combustion air intake piping. The termination
inlet must be positioned within 3” of the companion exhaust piping.
The combustion air inlet must be located a minimum of 12” above
grade, and 12” below the exhaust outlet.
(Figure 11)
10.2 exhaUsT
HORIzONTAL -
The exhaust termination is normally a 45° elbow or a medium or long sweep 90° elbow
pointing within 45° of the downward position, away from the combustion air intake terminal.
If the required clearance to grade cannot be obtained with the “straight through” configuration, the exhaust
pipe may be “periscoped” up to 24” to gain extra height.
(Figure 9)
In this case, the flue gases may be expelled
horizontally. use the same size pipe as the interior run and count the fittings and length as part of the total vent length.
If winter prevailing wind conditions are variable and likely to occasionally blow flue gases back in on the
combustion air intake, the exhaust termination may be raised 18-24” above the combustion air intake terminal
to take advantage of the natural buoyancy of the flue gases to help prevent re-circulation of the exhaust.
(Figure 9)
vERTICAL -
No termination fitting is required if venting vertically through a roof. The end of the exhaust pipe
must be 12” higher than the entrance of the combustion air intake terminal.
(Figure 11)
The exhaust pipe extending through the roof must extend a minimum of 18” above any obstruction within an
18” horizontal distance.
Insulate all venting that extends 24” or more to the outside.
10.3 ConCenTRIC venTInG KIT
Concentric venting terminal kits may be used for this series furnace. They provide a means of obtaining
combustion air and exhausting products of combustion utilizing a single penetration through the exterior
wall. This can be useful when there is limited wall space available. kits are available in 2” and 3” sizes. If
venting the 45k or 60k btu/hr model with 1½” vent material, and a concentric vent kit is necessary, a increase
coupling may be used to connect to the 2” concentric venting kit. Read the instructions supplied with the kit for
additional installation instructions and details.
10.4 ConCenTRIC venT TeRMInaTIon InsTallaTIon InsTRUCTIons
Follow the concentric vent termination manufacturer instructions for installation of the concentric vent
termination kit. These instructions can be found by contacting the furnace manufacture. Furnace
manufacturer contact information is found on the front cover of this installation manual and operating
instructions.
12” MIN.
ROOF TERMINATION
EXHAUST
3” MIN.
18”
MIN.
12” MIN.
FIGURE 11 - STANDARD vERTICAL
vENTING DETAIL
10.5 loCaTIon
Avoid locating the terminals where the flue gas could become stagnant and allow recirculation into the
combustion air intake.
Avoid locating the terminal in locations where dripping condensate may cause problems such as sidewalks,
patios, above planters, near windows where exhaust gases may cause fogging, etc.
