Raypak 88AR-398A, Installation & Operating Instructions Manual

Page: 30 / 68

11. DO NOT extend exposed vent pipe outside of
building beyond the minimum distance required
for the vent termination. Condensate could freeze
and block 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 ft below, 4 ft hori-
zontally from or 1 ft above any door, window or
gravity air inlet to the building.
2. The vent must not be less than 7 ft above grade
when located adjacent to public walkways.
3. Terminate vent at least 3 ft above any forced air
inlet located within 10 ft.
4. Vent must terminate at least 4 ft horizontally, and
in no case above or below unless 4 ft horizontal
distance is maintained, from electric meters, gas.
5. Terminate vent at least 6 ft away from adjacent
walls.
6. DO NOT terminate vent closer than 5 ft below roof
overhang.
7. The vent terminal requires a 12 in. vent terminal
clearance from the wall.
8. Terminate vent at least 1 ft above grade, including
normal snow line.
9. Multiple direct vent installations require a 4 ft
clearance between the ends of vent caps located
on the same horizontal plane.
Installations in Canada
Refer to latest edition of the B149 Installation Code.
A vent shall not terminate:
1. Directly above a paved sidewalk or driveway
which is located between two single-family dwell-
ings and serves both dwellings.
2. Less than 7 ft (2.13 m) above a paved sidewalk or
paved driveway located on public property.
3. Within 6 ft (1.8 m) of a mechanical air supply inlet
to any building.
4. Above a meter/regulator assembly within 3 ft (915
mm) horizontally of the vertical centerline of the
regulator.
5. Within 6 ft (1.8 m) of any gas service regulator
vent outlet.
6. Less than 1 ft (305 mm) above grade level.
7. Within 3 ft (915 mm) of a window or door which
can be opened in any building, any non-mechani-
cal air supply inlet to any building or the
combustion air inlet of any other appliance.
8. Underneath a verandah, porch or deck, unless the
verandah, porch or deck is fully open on a mini-
mum of two sides beneath the floor, and the
distance between the top of the vent termination
and the underside of the verandah, porch or deck
is greater than 1 ft (305 mm).
30
VENT CAPS STACKED VERTICALLY
FLUE GASES MOVING IN PARALLEL
VENT CAPS ALL AT SAME ELEVATION
FLUE GASES MOVING TOWARD EACH OTHER
VENT CAPS AT STAGGERED ELEVATIONS
FLUE GASES MOVING TOWARD EACH OTHER
1” MINIMUM (TYP)
2” MINIMUM (TYP)
1” MINIMUM (TYP)
DISCHARGE
4’-0” MIN.
(TYP)
4’-0” MIN.
(TYP)
DISCHARGE
Fig. 26: Vent Cap Configurations
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 62 of this
manual.