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V
ERTICAL VENT THROUGH THE ROOF
It is the sole responsibility of the installer to adhere
to all current local codes and/or ANSI Z223.1 /
CSA.B149.1 latest editions for all venting require-
ments, and practices.
Use an approved 'B-vent' termination cap as
supplied by the manufacturer of the approved
'B-vent'.
When vent and combustion air are taken
through the roof, the exhaust vent should al-
ways terminate higher than the combustion air
intake, to prevent recycling the products of
combustion back into the heater.
Maximum allowable 4" [100 mm] diameter vent length equivalent to 20 feet [6 m]
A maximum of three 90° elbows (each equivalent 5 ft) can be installed in a vertical vent
10. COMBUSTION AIR DUCTING
Whenever possible, locate the air intake and vent terminals in a common pressure area. For ex-
ample on a common wall, or commonly through the roof. Depending upon wind conditions, termi-
nations located in uncommon pressure areas can create intermittent operation problems.
Combustion Air Duct can be 4", or 5" diameter (reduce to 4" only at connection to blower collar).
4" Dia. Air Duct: Maximum combined total length of flue vent plus combustion air duct
equivalent to 35 feet, and neither the 4" diameter vent or duct component can exceed 20 feet.
5" Dia. Air Duct: Maximum combined total length of flue vent plus combustion air duct
equivalent to 50 feet. The 4" diameter vent cannot exceed 20 feet; the 5" diameter air duct can-
not exceed 35 feet.
Total vent and duct length is reduced by five feet for every 90° elbow installed in the vent
and/or duct system
Exceeding the allowable lengths noted above may cause unreliable operation, create con-
densation or soot conditions, and will void CSA Certification and the heater warranty.
An opening is located on the top surface of the burner housing for combustion air . Ensure ade-
quate clearance around this opening to allow sufficient combustion air supply to the heater.
Combustion air duct must be constructed of noncombustible material.
When a tube heater is operated in a negative air condition, or air-born dust or contaminants are
present as in woodworking and welding shops, air for combustion must be ducted from outside
the negative or contaminated area to the 4 inch (10 cm) diameter intake collar supplied on the
blower. See notes above for maximum combined equivalent vent and duct length.
The air intake will not be located less than:
Three feet above grade
Twelve inches from flue vent terminal of any heater with input up to 100,000 Btu/hr
Three feet from flue vent terminal of any heater over 100,000 Btu/hr
Do not install filters on the combustion air intake. Ensure adequate clearance around the
air intake to allow sufficient combustion air supply to the heater.
P40U-F / P40U-IF I&O Manual
IM101220
RD: MAR 2014
RL: 4B
FIGURE 11
:
Approved
Cap
Approved
'B' Vent
20
24"
Up
60 cm
9
to
12
If roof slope exceeds 9:12
consult NFPA-54 ANSI
Z223.1 or CSA-B149.1
continued ...
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