Horizontal terminations should be as shown in the following fig- ure. Refer to Section IX, Vent/Flue Pipe and Combustion Pipe - Termination Location for location restrictions. A 2 3/8 inch diameter wall penetration is required for 2” diameter pipe while a 3 1/2 inch diameter hole is required for 3” diameter pipe. To secure the pipe passing through the wall and prohibit damage to piping connec- tions, a coupling should be installed on either side of the wall and solvent cemented to a pipe connecting the two couplings. The pipe length should be the wall thickness plus the depth of the socket fittings to be installed on the inside and outside of the wall. The wall penetration should be sealed with silicone caulking ma- terial.
12" MIN
3" MIN 24" MAX
3" MIN
24" MAX
Standard Horizontal Terminations (Dual Pipe)
90°
MEDIUM
RADIUS 
ELBOW
24" MAX
24" MAX | 3" | MIN |
|
|
|
AIR 
INTAKE
Alternate Horizontal Vent Termination (Dual Pipe)
| 12" MIN |
| 3" MIN. |
| 24" MAX. |
| VENT/FLUE |
SUPPORT | TEE |
STRAPS |
|
COMBUSTION | 12" MIN. ABOVE |
HIGHEST ANTICIPATED | |
AIR INTAKE. | SNOW LEVEL |
SCREEN | 12" MIN. ABOVE |
90° | HIGHEST ANTICIPATED |
MEDIUM | SNOW LEVEL |
RADIUS |
|
ELBOWS |
|
Standard Horizontal Terminations Above Anticipated Snow
Level (Dual Pipe)
Alternate Vent Termination Above Anticipated Snow Level
(Dual Pipe)
In a basement installation, the pipes may be run between the joist spaces. If the pipes must go below the joist and then up into the last joist space to penetrate the header, two 45° elbows should be used to reach the header rather than two 90° elbows.
VENT/INTAKE TERMINATIONS FOR INSTALLATION OF MULTIPLE DIRECT VENT FURNACES
If more than one direct vent furnace is to be installed vertically through a common roof top, maintain the same minimum clear- ances between the exhaust vent and air intake terminations of adjacent units as with the exhaust vent and air intake terminations of a single unit.
If more than one direct vent furnace is to be installed horizontally through a common side wall, maintain the clearances as in the following figure. Always terminate all exhaust vent outlets at the same elevation and always terminate all air intakes at the same elevation.
90° | Vents |
Medium |
|
Radius |
|
Elbows |
|
3" Min. 24" Max.
3" Min.
24" Max. | 24" Max. | |
3" Min. | ||
|
Screen
12" Min.
Horizontal Venting Of Multiple Units
CONCENTRIC VENT TERMINATION
Refer to the directions provided with the Concentric Vent Kit (DCVK) for installation specifications.
X. CONDENSATE DRAIN LINES & DRAIN TRAP
GENERAL
A condensing gas furnace achieves its high level of efficiency by extracting almost all of the heat from the products of combustion and cooling them to the point where condensation takes place. The condensate which is generated must be piped to an appropri- ate drain location.
In upright installations, the furnace’s drain hoses may exit either the right or left side of the furnace. NOTE: If the alternate vent/flue outlet is utilized in an upright installation, the drain trap and drain connections must be located on the same side as the alternate vent/flue outlet.
In horizontal installations, the drain hoses will exit through the bottom (down side) of the unit with the drain trap suspended be- neath the furnace. The
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