Fig. 8: Minimum Clearances from Combustible
Surfaces – Outdoor Installations
Combustion and Ventilation Air
NOTE: Use of the heater in construction areas where fine particulate matter, such as concrete or
Indoor Units
The heater must be supplied with sufficient quantities of
CAUTION: Combustion air must not be contaminated by corrosive chemical fumes which can damage the heater and void the warranty. (See the Appendix.)
NOTE: It is recommended that the intake vent be insulated to minimize sweating.
Reversing Air Filter
Follow these instructions to change the air duct con- nection from the
1.Remove the four screws and the dust cover from the
2.Remove the four screws and the air filter bracket from the
3.Reverse the components and reattach in the new location, making sure that the air filter locking bracket is on the bottom. (The air filter locking bracket is reversible.)
Direct-Ducted Combustion Air
In certain applications it may be desirable to duct the combustion air directly to the heater. This should be done with PVC, CPVC or
Conventional Combustion Air Supply
U.S. Installations
All Air from Inside the Building
The confined space shall be provided with TWO per- manent openings communicating directly with an additional room(s) of sufficient volume so that the com- bined volume of all spaces meets the criteria for a room large in comparison (NFGC). The total input of all gas utilization equipment installed in the combined
CAUTION: This type of installation is recommended if damaging airborne contaminants are or will be present in the heater area. See the Appendix regarding air contamination.
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