Lochinvar 495, 065 Combustion Air Options, One Opening, Outside Combustion Air - Two Openings

Installation and Service Manual

Combustion Air Options

￿CAUTION: Under no circumstances should the mechanical room ever be under a negative pressure. Particular care should be taken where exhaust fans, attic fans, clothes dryers, compressors, air handling units, etc., take away air from the unit.

1.Outside Combustion Air, No Ducts You can direct outside combustion air to this unit using either one or two permanent openings.

One Opening

The opening must have a minimum free area of one square inch per 3000 Btu input (7cm2 per kW). You must locate this opening within 12" (30cm) of the top of the enclosure.

Figure 6 - Outside Combustion Air - Single Opening

Figure 7 - Outside Combustion Air - Two Openings

2. Outside Combustion Air, Using Ducts

You can direct outside combustion air to this unit using two air ducts to deliver the air to the boiler room.

Each of the two openings must have a minimum free area of one square inch per 2000 Btu input (11cm2 per kW).

Two Openings

The combustion air opening must have a minimum free area of one square inch per 4000 Btu input (5.5cm2 per kW). You must locate this opening within 12" (30cm) of the bottom of the enclosure.

The ventilation air opening must have a minimum free area of one square inch per 4000 Btu input (5.5cm2 per kW). You must locate this opening within 12" (30cm) of the top of the enclosure.

Figure 8 - Outside Combustion Air Through Ducts

3. Combustion Air from Interior Space

You can direct combustion air to this unit using air from an adjoining interior space. You must provide two openings from the boiler room to the adjoining room.

Each of the two openings must have a net free area of one square inch per 1000 Btu input (22cm2 per kW), but not less than 100 square inches (645cm2).

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