Lochinvar 90, 500 service manual Determine boiler location, 3Combustion Air Direct from Outside

Installation & Service Manual

1Determine boiler location

Combustion and ventilation air requirements for conventionally vented appliances

Provisions for combustion and ventilation air must be in accordance with the latest edition of the National Fuel Gas Code, ANSI Z223.1, in Canada, the latest edition of CGA Standard B149 Installation Code for Gas Burning Appliances and Equipment, or applicable provisions of the local building codes.

The room where the appliance is installed MUST be provided with properly sized openings to assure adequate combustion air and proper ventilation when the appliance is installed with conventional venting.

Figure 1-3_Combustion Air Direct from Outside

1.If air is taken directly from outside the building with no duct, provide two permanent openings (see FIG. 1-3):

(a)Combustion air opening, with a minimum free area of one square inch per 4000 Btu/hr input (5.5 cm2 per kW). This opening must be located within 12" (30 cm) of the floor.

(b)Ventilation air opening, with a minimum free area of one square inch per 4000 Btu/hr input (5.5 cm2 per kW). This opening must be located within 12" (30 cm) of the ceiling.

Figure 1-4_Combustion Air Through Ducts

2.If combustion and ventilation air is taken from the outdoors using a duct to deliver the air to the room where the appliance is installed, each of the two openings should be sized based on a minimum free area of one square inch per 2000 Btu/hr (11cm2 per kW) (see FIG. 1-4).

Figure 1-5_Combustion Air from Interior Space

3.If air is taken from another interior space that is adequately ventilated, each of the two openings specified above should have a net free area of one square inch for each 1000 Btu/hr (22cm2 per kW) of input, but not less than 100 square inches (645cm2) (see FIG. 1-5).

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