Install Instructions

38
APPENDIX B2 – DIRECT VENTING
Planning a Direct Vent System
1. Avoid contact with plumbing or electrical
wires.
2. Horizontal vent pipe must maintain a
minimum ¼ inch per foot slope down
towards boiler.
3. Any condensate forming in the vent will
return to the boiler. Provide for a condensate
trap or siphon near the boiler to remove
condensate from the vent.
4. Support the piping to maintain vent location
and prevent sag. The vent and/or air intake
piping must be adequately supported with
straps or supports with a maximum spacing
of ve (5) feet on horizontal runs.
5. Adhere to the boiler’s maximum and
minimum allowable vent lengths. Vent length
is provided in terms of equivalent length of
straight pipe plus equivalent length of ttings,
including both the vent and the combustion
air piping, but not including vent or intake
terminals.
6. Maintain minimum allowable clearances
between the vent pipe and combustible
materials as specied by the vent pipe
supplier, this manual, and applicable building
codes.
7. Do not install venting system components
on the exterior of the building except as
specically required by these instructions.
8. Locate the vent terminal per these
restrictions and Figure B-2:
(1) Minimum twelve (12) inches above
grade plus normally expected snow
accumulation level, or seven (7) feet
above grade, if located adjacent to
public walkway. Do not install over
public walkway where local experience
indicates appliance ue gas vapor
or condensate creates a nuisance or
hazard.
(2)
Minimum three (3) feet above any
forced draft combustion air intake
located within ten (10) feet.
(3)
Minimum four (4) feet horizontally from
unsheltered electric meters, gas meters
(six (6) feet Canadian Installations), gas
regulators, and gas relief valves.
(4)
Minimum twelve (12) inches from
overhangs or corners of buildings.
(5)
If window and/or air inlet is within four
(4) feet of an inside corner, then vent
terminal must be at least six (6) feet
from adjoining wall of inside corner.
(6)
Minimum one (1) foot below, one (1)
foot horizontally from, or one (1) foot
above any door, window, or gravity air
inlet.
GENERAL WARNINGS FOR DIRECT VENT SYSTEMS
DRAFTHOODS, VENT DAMPERS and other
obstructions or openings in the vent system are
prohibited.
DO NOT REDUCE THE DIAMETER of the vent
pipe.
MOISTURE AND ICE may collect around and
below the vent terminal. Keep the area in good
repair.
IF USING A CHIMNEY AS A CHASE for the vent,
do not vent any other appliance into the space
between the chimney wall and the vent.
ELIMINATE LOW SPOTS in the vent where ue
gas condensate may pool.
DO NOT PENETRATE VENT PIPE with holes or
fasteners.