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NOTE
Clearances from combustible construction are noted on the appliance rating plate.
Maintain minimum specified clearances for adequate operation. All installations must allow sufficient space for servicing the vent connections, water pipe connections, integral circulating pump, bypass piping and other auxiliary equipment, as well as the appliance. The clearance labels on each appliance note the same service and combustible clearance requirements as shown in the clearances from combustion construction table.
Multiple appliances may be installed in a modular boiler or water heater installation. Multiple appliances may be installed side by side with no clearance between adjacent appliances because this appliance is approved for zero clearance from combustible surfac- es and no service access is required from the sides.
Consult the venting section of the manual for specific installation instructions for the appropriate type of venting system that you will be using. Direct Vent and
COMBUSTION AND VENTILATION
AIR REQUIREMENTS FOR
APPLIANCES DRAWING AIR FROM
THE EQUIPMENT ROOM
Provisions for combustion and ventilation air must be in accordance with Section 5.3, Air for Combustion and Ventilation, of the latest edition of the National Fuel Gas Code, ANSI Z223.1, in Canada, the latest edition of CAN/CGA Standard B149 Installation Code for Gas Burning Appliances and Equipment, or applicable provisions of the local building codes.
The equipment room MUST be provided with properly sized openings to assure adequate combustion air and proper ventilation when the unit is installed with a basic Category IV venting system.
FIG. 5 Combustion Air Direct from Outside
1. If air is taken directly from outside the building with no duct, provide two permanent openings:
a.Combustion air opening, with a minimum free
area of one square inch per 4000 Btu input (5.5 cm2 per kW). This opening must be located within 12" (30cm) of the bottom of the enclosure.
b. Ventilation air opening, with a minimum free area of one square inch per 4000 Btu input (5.5 cm2 per kW). This opening must be located within 12" (30 cm) of the top of the enclosure.
FIG. 6 Combustion Air Through Ducts
2.If combustion and ventilation air is taken from the outdoors using a duct to deliver the air to the mechanical room, each of the two openings should be sized based on a minimum free area of one square inch per 2000 Btu (11 cm2 per kW) of input.
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