14
COMBUSTION AIR SUPPLY
As with all gas-fired appliances, careful
consideration must be given in regard to the
provision of sufficient free air for combustion and
venting. The rules for such are found in the
National Fuel Gas Code, NFPA Standard 54.
The code supersedes anything found in print here
or in any other Yazaki documentation. Provided
here are guidelines to help toward proper
installation of the equipment.
When installed outdoors, no special
provisions are usually needed in regard to
combustion air. However, if the unit is in a
confined area outside, some issues could arise if
external forces cause a negative pressure area
around the unit. An example of such would be
having the unit installed in an alcove, yet a
strong, sustained wind blows by along the edge
of the building. Such occurrences are rare, but
should be considered.
Of greater concern are indoor installations,
especially in areas with more than one gas-fired
appliance. Keep in mind that whatever
combustion air supply is present, it must be
capable of supporting every gas-fired appliance
in the space while all of them operate at full
capacity. Combustion air openings are also often
the source for dilution air for Category I
appliances, so it is recommended to consult the
manuals on all appliance in the area in order to
ensure all requirements are being considered.
Never install a gas-fired appliance in an
unventilated space.
CH-K100
Upper Opening Lower Opening
Direct to
Outdoor
294
(1897)
x FAM 294
(1897)
x FAM
Ducted to
Outdoor
588
(3794)
x FAM 588
(3794
) x FAM
Direct to
Outdoor One
Opening
392
(2529)
x FAM n.a.
(Consult Louver Manufacturer for FAM value)
Dimensions are Inches²
(cm²)
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