Longer Vent Runs; Exhaust Vent And Intake Pipe Installation - Westinghouse WGR-076 Series Installation, Start-Up, Maintenance, Parts, Warranty

2. The total equivalent length of exhaust vent and intake pipe
should not exceed 150 feet.
a. The equivalent length of elbows, tees, and other fittings
are listed in the Friction Loss Table.
Friction Loss Equivalent in Piping and Fittings
Fittings or Piping
90 Degree Elbow*
45 Degree Elbow
Coupling
Air Inlet Tee
Straight Pipe
Concentric Kit
V500 2" Kit
V1000 3" Kit
V2000 4" Kit
Table 6 - *Friction loss for long radius elbow is 1 foot less. NOTE:
Consult Polypropylene venting instructions for friction loss and
pressure drop equivalents.
b. For example: If the exhaust vent has two 90
10 feet of PVC pipe we will calculate:
Exhaust Vent Equivalent Length = (2x5) + 10 = 20 feet.
Further, if the intake pipe has two 90
elbow, and 10 feet of PVC pipe, the following calculation
applies:
Intake Pipe Equivalent Length = (2x5) + 3 + 10 = 23 feet.
Finally, if a concentric kit is used we find:
Total Equivalent Length = 20 + 23 + 3 = 46 feet.
The total equivalent length is 46 feet, well below the
maximum of 150 feet.
c. Effort should be made to keep a minimum difference in
equivalent length between the exhaust vent and intake
pipe.
3. The minimum total equivalent length is 16 feet.
Do not exceed the maximum lengths for vent pipes. Excessive
length could result in heater shutdown and property damage.
Failure to provide a minimum total vent length of 16
equivalent feet could result in property damage and improper
product operation.
F. Longer Vent Runs
The maximum total equivalent length can be extended by
increasing the diameter of both the exhaust vent and intake
pipes. However, the transitions should begin a minimum of 15
equivalent feet from the water heater.
a. The maximum total equivalent length for increased
diameter vent pipes is 200 feet.
b. Transitions should always be made in vertical sections
of pipe to prevent the condensate from pooling in the vent
pipe.
Vent Connection Reducing Coupling
2"
Table 7 - Vent Run Transition
Equivalent Feet
2" 3"
5' 5'
3' 3'
0' 0'
0' 0'
1' 1'
3' 3'
1' N/A
N/A 1'
N/A 1'
o
elbows and
o
elbows, one 45
Vent Transition
3" x 2" 3"
c. Transition from 2" to 3" pipe should be made at the water
heater.
G. Exhaust Vent and Intake Pipe Installation
All joints of positive pressure vent systems must be sealed
completely to prevent leakage of flue products into the living
space. Failure to do so could result in property damage, serious
injury, or death.
1. Use only solid PVC or CPVC pipe or a Polypropylene vent
system approved for use with Category IV appliances.
FOAM CORE PIPING IS NOT APPROVED FOR EXHAUST VENT
APPLICATIONS. Foam core piping may be used on air inlet
piping only.
2. Remove all burrs and debris from joints and fittings.
3. When using PVC or CPVC pipe, all joints must be properly
cleaned, primed, and cemented. Use only cement and primer
approved for use with the pipe material. Cement must conform
to ASTM D2564 for PVC and ASTM F493 for CPVC pipe. NOTE:
DO NOT CEMENT POLYPROPYLENE PIPE.
4. Ensure the vent is located where it will not be exposed to
prevailing winds.
5. In all roof venting applications, exhaust discharge must point
away from the pitch of the roof.
6. To prevent water leakage, install adequate roof flashing where
o
the pipe enters the roof.
7. Do not locate vent over public walkways, driveways, or parking
lots. Condensate could drip and freeze, resulting in a slip hazard
or damage to vehicles and machinery.
8. Due to potential moisture build-up, sidewall venting may not
be the preferred venting option. To save time and cost, carefully
consider venting installation and location.
9. Horizontal lengths of exhaust vent must slope back towards
the water heater not less than ¼" per foot to allow condensate
to drain from the vent pipe.
10. The exhaust vent must terminate where vapors cannot make
accidental contact with people or pets, or damage shrubs or
plants.
11. In vacant chimney applications, install and seal a rain cap
over existing chimney openings.
12. All piping must be fully supported. Use pipe hangers at a
minimum of 4 foot intervals to prevent sagging of the pipe
where condensate may form.
13. Do not use the heater to support any piping.
14. A screened straight coupling is provided with the heater for
use as an outside exhaust termination.
15. A screened inlet air tee is provided with the heater to be
used as an outside intake termination.
The following table lists optional exhaust/intake terminations
available from Westinghouse:
Description
2" PVC Concentric Termination Kit
3" PVC Concentric Termination Kit
2" Stainless Steel Termination Kit
3" Stainless Steel Termination Kit
3" Polypro Vent Kit
Table 8 - Optional Vent Kits
19
Stock Code
KGAVT0501CVT
KGAVT0601CVT
V500
V1000
8400P-001
WHL-001 Rev. 3.16.15