10
Combustion and Ventilation Air
Indoor Units
This heater must be supplied with sufficient quantities
of non-contaminated air to support proper combustion
and equipment ventilation. Combustion air can be
sup-plied via conventional means where combustion
air is drawn from the area immediately surrounding
the heater, or via direct vent, where combustion air
is drawn directly from outside. All installations must
comply with the requirements of the NFGC (U.S.) and
NOTE:
Use of this heater in construction areas
where fine particulate matter, such as concrete or
dry-wall dust, is present may result in damage to
the heater that is not covered by the warranty. If
operated in a construction environment, a clean
source of combustion air must be provided directly
to the heater.
CAUTION:
Combustion air must not be contaminated
by corrosive chemical fumes which can damage the
heater and cause a non-warrantable failure. (See the
Appendix.)
CAUTION:
Do not install where the condensate can
freeze. Take appropriate measures.
NOTE:
It is recommended that the intake vent be
insulated to minimize sweating.
Table D: Clearances – Outdoor Installations
Heater Side
Minimum Clearance
from Combustible
Surfaces
Minimum
Service
Clearance
Rear
12"
36"
Front
Open
30"
Access Side
1"
24"
Opposite
Side
1"
1"
Top
Unobstructed
10"
Vent
Termination
12"
12"
AIR FILTER ACCESS PANEL
(BOTH SIDES)
Fig. 7: Outdoor Air Intake
When installed according to the listed minimum
clear-ances from combustible construction, these
heaters can still be serviced without removing per-
manent structural construction around the heater.
However, for ease of servicing, a clearance of at least
30 in. in front, 24 in. on one side, at least 36 in. on the
rear and 10 in. above the top of the heater is required.
This will allow the heater to be serviced in its installed
location without movement or removal of the heater.
Service clearances less than the minimum may
require removal of the heater to service either the
heat exchanger or the burner components. In either
case, the heater must be installed in a manner that will
enable the heater to be serviced without removing any
structure around the heater.
Outdoor Installation
These units may be installed outdoors when used with
the outdoor air intake hood. The outdoor hood must
be ordered when ordering the unit, and is shipped
loose for field installation.
Heaters must not be installed under an overhang
unless clearances are in accordance with local instal-
lation codes and the requirements of the gas supplier.
Three sides must be open in the area under the over-
hang. Roof water drainage must be diverted away
from heaters installed under overhangs.
