Piping must be mechanically supported so that its weight does not bear on the furnace. Sup- ports must be at intervals no greater than five feet, and at smaller intervals if necessary to ensure that there are no sagging sections to trap water. (See Figures 14 and 15.)
Figure 16 illustrates vent and combustion air pipe sizes exiting the furnace. Transition to the correct pipe size must be done close to the furnace so that the full length of pipe is of proper size.
Straight neoprene couplings are supplied with the downflow furnaces only. These couplings are to be installed in the combustion air inlet (if present) and exhaust vent piping at the furnace as shown in Figures 13 and 14. For an upflow furnace installation, if breakable connections are required in the combustion air inlet (if present) and exhaust vent piping, then straight neoprene couplings for 2” or 3” piping with hose clamps can be used. These couplings can be ordered through your local furnace distributor.
To install a coupling, slide the rubber coupling over the end of the pipe that is attached to the furnace and secure it with one of the hose clamps. Then slide the other end of the rubber coupling onto the other pipe from the vent and secure the coupling with the second hose clamp. Ensure that the connection is tight and leak free.
NORDYNE condensing furnaces have been certified for installation with zero clearance be-
tween vent piping and combustible surfaces. However, it is good practice to allow space for convenience in installation and service.
Location of Outdoor Terminations
Vent and combustion air intake terminations must be located to ensure proper furnace opera- tion and to conform to applicable codes. Figure
16illustrates necessary distances from the vent termination to windows and building air intakes.
In Canada, the Canadian Fuel Gas Code takes precedence over these instructions. Specifically, all minimum distance require- ments with respect to termination of the vent piping listed below (items 1 through 8).
The following list is a summary of vent terminal location requirements:
1.The termination must be 12 inches above snow level or grade level whichever is higher. See Figure 18 for alternate method to achieve 12" above snow level.
2.The minimum distance for a
3.The minimum distance for a direct vent (2- pipe) installation) from any door, (openable) window, or air gravity inlet is 1 ft. below, 1 ft. horizontally, or 1 ft. above.
4.For
Direct vent terminal 50,000 Btuh or less
9 in.
12 | in. | 4 ft. min |
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| ft. |
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| min |
| 4 | min | |
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| Mechanical | 12 | in. | ||
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| draft vent |
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| min |
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terminal
Mechanical |
| Mechanical | |
| draft vent | ||
draft vent |
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| terminal | ||
terminal |
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| Less |
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| than 10 ft. |
| .min |
| 3 ft. min. |
in |
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12 |
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| Grade |
.min |
| Forced | |
in |
| Air Inlet | |
12 | .min | ||
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12 | in | Direct vent | |
| terminal - | ||
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more than 50,000 Btuh
Figure 17. Vent Termination Clearances
18