Raypak X94 Installation & Operating Instructions Manual - page 18
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Support of Vent Stack
The weight of the vent stack or chimney must not rest
on the heater vent connection. Support must be pro-
vided in compliance with applicable codes. The vent
should also be installed to maintain proper clearances
from combustible materials. Use insulated vent pipe
spacers where the vent passes through combustible
roofs and walls.
Vent Terminal Location
1. Condensate can freeze on the vent cap. Frozen
condensate on the vent cap can result in a blocked
flue condition.
2. Give special attention to the location of the vent
termination to avoid possibility of property dam-
age or personal injury.
3. Gases may form a white vapor plume in winter.
The plume could obstruct a window view if the ter-
mination is installed near windows.
4. Prevailing winds, in combination with below-freez-
ing temperatures, can cause freezing of conden-
sate and water/ice build-up on buildings, plants or
roofs.
5. The bottom of the vent terminal and the air intake
shall be located at least 12” (304.8 mm). above
grade, including normal snow line.
6. Un-insulated single-wall metal vent pipe shall not
be used outdoors in cold climates for venting gas-
fired equipment.
7. Through-the-wall vents for Category IV appliances
shall not terminate over public walkways or over
an area where condensate or vapor could create a
nuisance or hazard or could be detrimental to the
operation of regulators, relief valves, or other
equipment.
8. Locate and guard vent termination to prevent acci-
dental contact by people or pets.
9. DO NOT terminate vent in window well, stairwell,
alcove, courtyard or other recessed area.
10. DO NOT terminate above any door, window, or
gravity air intake. Condensate can freeze, causing
ice formations.
11. Locate or guard vent to prevent condensate from
NOTE: During winter months check the vent cap
and make sure no blockage occurs from build-up of
snow or ice.
damaging exterior finishes. Use a rust-resistant
sheet metal backing plate against brick or mason-
ry surfaces.
12. DO NOT extend exposed vent pipe outside of
building beyond the minimum distance required
for the vent termination. Condensate could freeze
and block the vent pipe.
U.S. Installations
Refer to the latest edition of the National Fuel Gas
Code.
Vent termination requirements are as follows:
1. Vent must terminate at least 4’ (1.22 m) below, 4’
(1.22 m) horizontally from or 1’ (0.3 m) above any
door, window or gravity air inlet to the building.
2. The vent must not be less than 7’ (2.13 m) above
grade when located adjacent to public walkways.
3. Terminate vent at least 3’ (0.91 m) above any
forced air inlet located within 10’ (3.05 m).
4. Vent must terminate at least 4’ (1.22 m) horizon-
tally, and in no case above or below unless 4’
(1.22 m) horizontal distance is maintained, from
electric meters, gas meters, regulators, and relief
equipment.
5. Terminate vent at least 6’ (1.8 m) away from adja-
cent walls.
6. DO NOT terminate vent closer than 5’ (1.52 m)
below roof overhang.
7. The vent terminal requires a 12” (304.8 mm) vent
terminal clearance from the wall.
8. Terminate vent at least 1’ (0.3 m) above grade,
including normal snow line.
9. Multiple direct vent installations require a 4’
(1.22 m) clearance between the ends of vent caps
located on the same horizontal plane.
Canadian Installations
Refer to latest edition of the B149 Installation code.
WARNING: The Commonwealth of Massachusetts
requires that sidewall vented heaters, installed in
every dwelling, building or structure used in whole or
in part for residential purposes, be installed using
special provisions as outlined on page 50 of this
manual.