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1.8 Vent Requirements and Details
1.8.1 Unvented units
Heaters maybe installed without a vent
providing the governing building codes are met
and consideration is properly given to
possibilities of condensation on cold surfaces.
Installation shall meet the following
requirements when unvented:
•
Internal volume of the heated room must
be greater than 214cu.ft. per 100 BTU/
HR of heaters installed.
OR
•
Natural or mechanical means shall be
provided to supply and exhaust at least 4
CFM per 1000 BTU per hour input of
installed heaters.
•
Combustion gasses shall not impinge on
combustible materials with a temperature
in excess of 150°F.
1.8.2 Vertical venting
The heater can be installed with a vertical vent.
All vent piping should be adequately supported
from the building structure and terminated with
an approved terminal. All connections should
be properly sealed. refer fig 8a & 8c
1.8.3 Horizontal venting
Individual units can be vented horizontally
through side walls. Recommended terminals
are AmbiRad V0700 for 4” and V0800 for 6”.
Distances from adjacent public walkways,
adjacent buildings, openable windows and
building openings, consistent with the
National
Fuel Gas Code, ANSI Z223.1/NFPA 54.
Maximum length of vent is 25ft with 2 - 90° long
radius elbows.
Runs of 12ft or shorter can use 4” dia vent.
Runs over 12ft should use 6” vent pipe.
Any portion of vent that passes through a
combustible wall must be insulated, or use an
approved insulating thimble.
Standard vent terminals must extend at least 6”
from the wall and at least 24” from any
combustible overhang. Protect the building
material from degradation by the vent gasses.
Vent joints should be sealed and secured using
at least 3 sheet metal screws. Should
condensation occur the vent should be
shortened or insulated.
The terminal should be at least 3ft away from
any air intake to the building
If the heater is equipped with ducted combustion
air, the vent terminal must be at least 3ft away
from the air inlet and located higher than the
inlet.
The vent terminal must be protected from
blockage by snow.
1.8.4 Fresh Air Intake
Whenever the heater is installed in locations
where airbourne dust or other pollutants are
present, a fresh air supply should be ducted to
the burner.
A fresh air duct of 4” dia. Should be installed
from the fresh air to the air intake connection on
the fan housing.
A flexible jointing piece should be installed at
the fan connection with hose clamps to facilitate
expansion and contraction.
The maximum recommended length air duct is
25ft and the maximum number of bends is 2.
The minimum length is 18”.
The location of the fresh air duct inlet must be
where it will receive dust free clean air.
An inlet cap with bird screen must be fitted at
the inlet of the duct.
If the duct inlet is located above the roof the
underside of the inlet terminal must be at least
2ft above roof level and at least 10” above any
projection on the roof within 7ft of the inlet.
Intake pipe, fittings and sealant are not
furnished by the manufacturer. Refer fig 8a and
8b.