Comfort Bilt HP50S Owner's Manual page 13

Installation
Venting (Continued)
Pro Tip: Installing a clean-out "T" (sold separately), when venting vertically, can save time during
cleaning, and is recommended to aid in the periodic cleaning and maintenance.
Be aware of leak potential when installing an interior Tee.
Do not install flue damper in the exhaust venting system of this unit.
Use an approved wall thimble when passing the vent through walls. Use a ceiling support/fire stop spacer
when passing the vent through ceilings. (Make sure to maintain minimum clearances to combustibles).
If using more than one T-vent or exceeding 180° of elbows, the use of 4" venting pipe is recommended.
The vent must have a support bracket every 5' of pellet vent when on the exterior of the structure.
Horizontal sections of vent pipe should have a 1/4 inch rise per foot. We recommend using the shortest
venting and fewest elbows possible when venting horizontal.
Due to the potential for fly ash accumulation in horizontal venting sections, the maximum permissible
horizontal venting length is 4 ft.
Contact local building or fire officials about restrictions and installation inspection requirements in your
area.
Contact your local authority (such as municipal building department, fire department, fire prevention
bureau, etc.) to determine the need for a permit.
Pro Tip: Use the bottom adjustable leveling feet for vertical movement of the stove up to 3/4".
Outside Air Intake (available separately)
Connection from the intake pipe (2" diameter pipe in rear of stove) to the outside of the house is
REQUIRED for mobile home installation. It is recommended in tightly sealed homes with exhaust fans
such as kitchen or bathroom fans, or in basement installations. This will eliminate poor performance due to
negative pressure.
Only noncombustible pipe 2" (or greater) in diameter is approved for outside air connections (Straight or
flexible). PVC pipe is NOT approved and should NEVER be connected to the stove.
If the air inlet is connected to the outside, it MUST be terminated with a vertical 90° bend down, or with a
wind hood. Failure to do so could result in a burn-back if high winds blow directly into the air inlet during a
power outage.
Blockages, excessive length (more than 8 ft.), or excessive bends in the air intake pipe could lead to
starvation of combustible air to the stove.
To prevent excess moisture from entering the stove, be sure to remove and/or cap this intake during the
off season.
Notice: The operation of exhaust fans, such as bathroom and attic fans, could create a negative pressure
in the room, causing the stove to be starved of combustible air. Be sure to provide adequate ventilation in
the room the pellet stove is located. If not, the vacuum pressure switch may shut off the operation of the
pellet stove.
Equivalent Vent Length: Comfortbilt pellet stoves
depend on a combustion fan to pull air through the
unit for combustion. The venting system restricts the
ability of the combustion fan to move the required
amount of air through the unit. A system with too
much resistance will result in incomplete
combustion, more frequent required cleaning and
poor unit performance. It is always best to choose a
location for the appliance that will result in a venting
system with the shortest equivalent vent length
(EVL).
The following chart shows the equivalent vent length
for common pellet vent components.
Equivalent Vent Length:
90° Elbows or Tee: (Each)
45° elbow: (Each)
Horizontal Pipe or liner: (Per Ft)
Vertical Pipe or Liner: (Per Ft.)
Maximum allowable equivalent vent length:
17 EVL for 3" pellet vent pipe or liner
27 EVL for 4" pellet vent pipe or liner
13
5 EVL Units
3 EVL Units
1 EVL Units
½ EVL Units
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