Elbow Dimensions; Equivalent Length Of Fittings; Combustion Air Intake And Vent Connection Size At Furnace (All Models); Dimensions - Johnson Controls YP9C Series Installation Manual

5750151-UIM-G-0423
A
STANDARD ELBOW
Figure 29: Dimensions
Table 7: Elbow dimensions
Elbow "A" Dimension (Illustrated in Figure 29)
2 in. Standard
3 in. Standard
2 in. Sweep
3 in. Sweep
Dimensions are those required in Standard ASTM D-3311.
Table 8: Equivalent length of fittings
Fitting
2 in. 90° sweep elbow
2 in. 45° sweep elbow
2 in. 90° standard elbow
2 in. 45° standard elbow
3 in. 90° sweep elbow
3 in. 45° sweep elbow
3 in. 90° standard elbow
3 in. 45° standard elbow
4 in. 90° elbow (sweep or stan-
dard)
4 in. 45° elbow (sweep or stan-
dard)
Example:
An 80,000 Btu/h furnace requires 32 ft of pipe and five 90º elbows.
Using 2 in. pipe and standard elbows, the total equivalent length will be:
32 ft of 2 in. pipe =
5 - 90º standard 2 in. elbows = (5 x 7) =
Total =
This exceeds the 65 foot maximum equivalent length of 2 in. pipe
allowed for that model and is thus not acceptable.
By using sweep elbows, the total equivalent length will be:
32 ft of 2 in. pipe =
5 - 90º sweep 2 in. elbows = (5 x 5) =
Total =
This is less than the 65 foot maximum equivalent length of 2 in. pipe
allowed for that model and is thus acceptable.
Alternatively, using 3 in. pipe and standard elbows, the total equivalent
length will be:
32 ft of 3 in. pipe =
5 - 90º standard 3 in. elbows = (5 x 7) =
Total =
24
A
LONG (SWEEP) ELBOW
2 5/16 in.
3 1/16 in.
3 1/4 in.
4 1/16 in.
Equivalent Length
5 ft of 2 in. pipe
2 1/2 ft of 2 in. pipe
7 ft of 2 in. pipe
3 1/2 ft of 2 in. pipe
5 ft of 3 in. pipe
2 1/2 ft of 3 in. pipe
7 ft of 3 in. pipe
3 1/2 ft of 3 in. pipe
5 ft of 4 in. pipe
2 1/2 ft of 4 in. pipe
32 equivalent ft
35 equivalent ft
67 equivalent ft of 2 in. pipe
32 equivalent ft
25 equivalent ft
57 equivalent ft of 2 in. pipe
32 equivalent ft
35 equivalent ft
67 equivalent ft of 3 in. pipe
This is less than the 90 ft maximum equivalent length of 3 in. pipe
allowed for that model and is thus acceptable.
Table 9: Combustion air intake and vent connection size at furnace (all
models)
Furnace vent connection sizes
Furnace Input
Intake Pipe Size
Vent Pipe Size
Important: Furnace vent pipe connections are sized for 2 in. (51
mm). pipe. Any pipe size change must be made outside the furnace
casing in a vertical pipe section to allow proper drainage of conden-
sate. An offset using two 45º elbows will be required for plenum clear-
ance when the vent is increased to 3 in. (76 mm).
Important: Accessory concentric vent / intake termination kits
1CT0302 and 1CT0303, and for Canadian applications ICT0302-636
and ICT0303-636 are available and approved for use with these fur-
naces. Horizontal sidewall vent terminations kits 1HT0901 and
1HT0902 are also approved for use with these furnaces. The above
listed termination kits are NOT to be used with CPVC vent piping.
Combustion air and vent piping assembly
The final assembly procedure for the combustion air and vent piping is
as follows:
1. Cut piping to the proper length beginning at the furnace.
2. Deburr the piping inside and outside.
3. Chamfer (bevel) the outer edges of the piping.
4. Dry-fit the vent piping assembly from the furnace to the outside ter-
mination checking for proper fit support and slope.
5. Dry-fit the combustion air piping assembly checking for proper fit,
support and slope on the following systems:
a. Sealed combustion air systems from the furnace to the outside
termination.
b. Ventilated combustion air systems from the furnace to the attic or
crawl space termination.
CAUTION
!
Solvent cements are flammable and must be used in well-ventilated
areas only. Keep them away from heat, sparks and open flames. Do
not breathe vapors and avoid contact with skin and eyes.
6. Disassemble the combustion air and vent piping, apply cement
primer and the cement per the manufactures instructions. Primer
and cement must conform to ASTM D2564 for PVC, ASTM D2235
for ABS piping, or ASTM F493 for CPVC.
7. All joints must provide a permanent airtight and watertight seal.
8. Install the combustion air and vent piping such that it has a 1/4 in.
per foot (21 mm/m) grade so that condensate will flow back towards
the furnace. Piping should be supported with pipe hangers to pre-
vent sagging.
9. Seal around the openings where the combustion air and / or vent
piping pass through the roof or sidewalls.

Combustion air/venting

Important: The vent must be installed with the required clearances,
and must comply with local codes and requirements.
All
2 in. (5.1 cm)
2 in. (5.1 cm)
Johnson Controls Ducted Systems