Lochinvar CW 745, CW 645 manual Venting, Contaminants, Lochinvar, General

Lochinvar

Btu (22 cm2 per kW) of input, but not less than 100 square inches (645 cm2).

VENTING

General

Copper-Fin II Water Heaters are classified as Category I appliances when tested to the latest ANSI Standard. This classification requires all conventionally vented combustion products to be vented using Category I listed vent pipe.

CAUTION!

EXHAUST FANS:

Any fan or equipment which exhausts air from the equipment room may deplete the combustion air supply and/or cause a down draft in the venting system. If a fan is used to supply combustion air to the equipment room, it must by sized such to make sure that it does not cause drafts which could lead to nuisance operational problems with the water heater.

(FIG. 6) COMBUSTION AIR FROM OUTSIDE,

SINGLE OPENING

4.If a single combustion air opening is provided to bring combustion air in directly from the outdoors, the opening must be sized based on a minimum free area of one square inch per 3000 Btu input (7 cm2 per kW). This opening must be located within 12” (30 cm) of the top of the enclosure.

CONTAMINANTS

Combustion air drawn from an interior or exterior space must be free of any chemical fumes which could be corrosive to the water heater.

Burning chemical fumes results in the formation of corrosive acids which attack the water heater, cause improper combustion and premature failure of the water heater and vent.

These fumes are often present in areas where refrigerants, salts, and solvents are used. Therefore, be aware of swimming pool equipment, water softening, and cooling system placement.

Additionally, it is recommended that this vent material be double wall construction or insulated in the field. A Category I appliance operates with a non-positive static vent pressure and with flue loss greater than 17 percent.

Vent installations for connection to gas vents or chimneys must be in accordance with Part 7, “Venting of Equipment,” of the latest edition of the National Fuel Gas Code, ANSI Z223.1, or applicable provisions of the local building codes.

The connection from the appliance vent to the stack must be as direct as possible and sized correctly. The horizontal breeching of a vent must have at least 1/4” rise per linear foot. The horizontal portions should also be supported for the design and weight of the material employed to maintain clearances, prevent physical damage and separation of joints.

The connection from the appliance vent to the stack or vent termination outside the building must be made with listed

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