Instructions / Assembly

LP-387 Rev. 011 Rel. 006 Date 6.28.19
31
Friction Loss Equivalent in Piping and Fittings
Fittings or Piping
Equivalent Feet
3” 4” 6”
90 Degree Elbow* 5’ 3’ 3’
45 Degree Elbow 3’ 3’ 2’
Coupling 0’ 0’ 0’
Air Inlet Tee 0’ 0’ 0’
Straight Pipe 1’ 1’ 1’
Concentric Kit 3’ N/A N/A
V Series Vent Kit 1’ 1’ 1’
AL20 4c Vent Terminal 1’ 1’ 1’
Table 11 - *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 is 3” in diameter, has two 90
o
elbows, and 10 feet of PVC pipe we will calculate:
Exhaust Vent Equivalent Length = (2x5) + 10 = 20 feet.
Further, if the 3” intake pipe has two 90
o
elbows, one 45
o
elbow,
and 10 feet of PVC pipe, the following calculation applies:
Intake Pipe Equivalent Length = (2x5) + 3 + 10 = 23 feet.
The total equivalent length is 43 feet, well below the maximum.
c. Eort should be made to keep a minimum dierence in
equivalent length between the exhaust vent and intake pipe.
3. The minimum total equivalent length is 16 feet.
F. Longer Vent Runs
The maximum total equivalent length can be extended by increasing
the diameter of both the exhaust vent and intake pipes equally.
However, the transitions should begin a minimum of 16 equivalent
feet from the boiler. Transitions should always be made in vertical
sections of pipe to prevent the condensate from pooling in the vent
pipe.
On all models EXCEPT the 285 model, the maximum equivalent length
for increased diameter vent pipes is 275 ft, which includes 16 ft from
with boiler with a transition total of 259 ft upsize piping for longer vent
runs. On the 285 model, the maximum equivalent length for increased
diameter vent pipes is 250 ft., which includes the 16 ft from the boiler
with a transition total of 234 ft upsize piping for longer vent runs.
Standard
Vent Connection
Reducing
Coupling
Increased Vent Size
3” 4” x 3” 4”
4” 6” x 4” 6”
6” 8” x 6” 8”
Table 12 - Vent Run Transition
Do not exceed the maximum lengths for vent pipes. Excessive length
could result in boiler shutdown and property damage.
G. Exhaust Vent and Intake Pipe Installation
All joints of positive pressure vent systems must be sealed
completely to prevent leakage of ue products into the living
space. Failure to do so could result in property damage, serious
injury, or death.
1. Use only solid PVC, CPVC, or stainless steel pipe or a Polypropylene
vent system approved for use with Category IV appliances.
ABS pipe material may be used on air inlet piping only.
2. Remove all burrs and debris from joints and ttings.
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. If the exhaust vent is to be terminated in a walled o area (such
as a roof with a parapet wall), ensure the exhaust vent terminates
a minimum of 10’ from nearest wall and extends level with or
above the top of the wall. This will ensure ue gas does does not
get trapped and possibly recirculated into the intake air pipe, which
could contaminate the combustion air.
7. To prevent water leakage, install adequate roof ashing where the
pipe enters the roof.
8. 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.
9. 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.
10. Horizontal lengths of exhaust vent must slope back towards the
boiler not less than ¼” per foot to allow condensate to drain from
the vent pipe.
11. The exhaust vent must terminate where vapors cannot make
accidental contact with people or pets, or damage shrubs or plants.
12. In vacant chimney applications, install and seal a rain cap over
existing chimney openings.
13. 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.
14. Do not use the boiler to support any piping.
15. Ensure the outdoor exhaust vent termination is screened to
prevent blockage caused by debris or birds.
16. Ensure the outdoor intake pipe termination is screened to
prevent blockage caused by debris or birds.
17. Maximum Snow Level Determination: These installation
Failure to provide a minimum total vent length of 16 equivalent feet
could result in property damage and improper product operation.
E. Exhaust Vent and Intake Pipe Sizing
1. The exhaust vent and intake pipe size is 3” for 55 - 285 models and
4” for the 399 model.
2. The maximum total equivalent length of exhaust vent and intake
pipe should not exceed 200 feet for all models EXCEPT the 285
model. Total equivalent length for the 285 model should not
exceed 150 feet.
a. The equivalent length of elbows, tees, and other ttings are
listed in the Friction Loss Table.
Total maximum equivalent length of increased diameter exhaust
vent and intake pipe must not exceed the lengths dened in this
manual. Failure to keep the total equivalent length below the
maximum lengths determined in this manual will result in faulty
boiler operation, substantial property damage, serious personal
injury, or death.
Figure 16 - Extended Vent Runs