Mestek SEPARATED COMBUSTION GAS FIRED PROPELLER UNIT HEATER, Installation Instructions & Parts List

Page: 15 / 32

15
INSTALLATION - VENTING (continued)
Never use pipe of a diameter
other than that specified in Table 1, page 4!
Never use PVC, ABS or any other non-metallic
pipe for venting! To do so may result in serious
damage to the unit and or severe personal injury
or death!
5. Any run of single wall vent pipe passing through an
unheated space must be insulated with an insulation
suitable to 550°F (288°C).
6. The vent system must be installed to prevent
collection of condensate. Pitch horizontal pipes
downward 1/4 inch per foot (21mm/m) toward the
vent cap to facilitate drainage. Vertical vent pipes
should be piped as depicted in Figure 10.
7. The equivalent length of the vent system must not
be less than 5 feet (1.5m) and must not exceed
50 feet (15.2m). Equivalent length equals the total
length of straight pipe plus 10 feet (4.6m) for each
90° elbow and 5 feet (1.5m) for each 45° elbow.
8. Each slip joint must be secured with at least three
corrosion resistant screws. Two full turns of 3M #425
Aluminum Foil tape or its equivalent must then be
used to seal each joint. General Electric RTV-108,
Dow-Corning RTV-732 or an equivalent may be used
instead of the tape.
9. For horizontal vent systems longer than 5 feet
(1.5m), the system must be suppor ted from
overhead building structures at 3 foot (1m) intervals.
10. The exhaust vent system must remain at a minimum
distance of 6 inches (152mm) from all combustible
materials. Any part of the vent system that passes
through a combustible material must be properly
insulated.
NOTICE: Increasing the clearance distances may
be necessary if there is a possibility of distortion or
discoloration of adjacent materials.
For a VERTICAL vent pipe section that passes through
a fl oor or roof, an opening 4 inches (102mm) greater in
diameter is required. The opening must be insulated and
fl ashed in accordance with applicable installation codes.
A HORIZONTAL section of an exhaust vent system that
passes through a combustible wall must be constructed
and insulated as shown in Figure 11A.
11. The top of a VERTICALLY VENTED exhaust system
must extend at least 3 feet (1m) above the roof surface
that it passes through. The point of termination for
a HORIZONTALLY VENTED exhaust system must
be at least 12 inches (305mm) from the exterior of
the wall that it passes through. Refer to Table 5 and
Figures 10A and 11A for additional vent termination
clearance requirements.
Table 5
Vent Systems
Termination Clearance Requirements
Structure/Object
Minimum Clearance
for Termination Locations
USA CANADA
Door, window, or gravity vent
inlet; combustion air inlet for
other appliances 9 inch for 10,000 to
50,000 BTU/Hr
input; 12 inch for
input exceeding
50,000 BTU/Hr. 9 inch (230mm) for
10,000 to 50,000
BTU/Hr input;
12 inch (305mm)
for input exceeding
50,000 BTU/Hr.
Forced air inlet within 10 feet 3 feet above 6 feet (1.8m)
Adjoining Building or parapet 6 feet 6 feet (1.8m)
Adjacent public walkways
7 feet above
grade 7 feet (2.1m) above
grade
Electric, gas meters
& regulators
4 feet horizontal
3 feet (0.9m)
horizontally from
meter/regulator
asembly. 6 feet
(1.8m), any
direction, from
a gas service
regulator vent outlet
Above grade level 1 foot 1 foot (0.3m)