Bradford-White Corp BWCV warranty Internet Version for Reference Only, Intake Combustion Air

Models: BWCV

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2.1.2 Intake Combustion Air

Internet Version for Reference Only

Copper Brute II

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the outdoors through horizontal ducts, each opening shall have a minimum free area of not less than

1 square inch per 2000 Btu/hr (11 square cm/kW) of total input rating of all equipment in the enclosure. Table 3 shows data for this sizing method, for each Copper Brute II model.

Method 2: One permanent opening, commencing within 12 inches (30 cm) of the top of the enclosure, shall be permitted. The opening shall directly communicate with the outdoors or shall communicate through a vertical or horizontal duct to the outdoors or spaces that directly communicate with the outdoors and shall have a minimum free area of 1 square inch per 3000 Btu/hr (7 square cm/kW) of the total input rating of all equipment located in the enclosure. This opening must not be less than the sum of the areas of all vent connectors in the confined space.

Other methods of introducing combustion and ventilation air are acceptable, providing they conform to the requirements in the applicable codes listed above.

In Canada, consult local building and safety

codes or, in absence of such requirements, follow CSA B149.1.

 

Each Opening*

Model

Square inches

Square cm

500

125

807

750

188

1213

1000

250

1613

1250

313

2020

1500

375

2420

1750

438

2826

2000

500

3226

*Net Free Area in Square Inches / Square cm

Area indicated is for one of two openings; one at floor level and one at the ceiling, so the total net free area could be double the figures indicated.

This chart is for use when communicating directly with the outdoors. For special conditions and alternate methods, refer to the latest edition of ANSI Z223.1.

Note: Check with louver manufacturers for net free area of louvers. Correct for screen resistance to the net free area if a screen is installed. Check all local codes applicable to combustion air.

Table 3. Combustion Air Openings.

2.1.2 Intake Combustion Air

The combustion air can be taken through the wall, or through the roof. When taken from the wall, it must be taken from out-of-doors by means of the Bradford White horizontal wall terminal (see Table 1). When taken from the roof, a field-supplied rain cap or an elbow arrangement must be used to prevent entry of rain water (see Figure 2).

Use single-wall galvanized pipe, per Table 4, for the combustion air intake (see Table 1 for appropriate size). Route the intake to the heater as

directly as possible. Seal all joints with tape. Provide adequate hangers. The unit must not support the weight of the combustion air intake pipe. Maximum linear pipe length allowed is 50 feet (15.2m). Three elbows have been calculated into the 50-foot (15.2m) linear run. Subtract 10 allowable linear feet (3.0m) for every additional elbow used (see Table 1). When fewer than 3 elbows are used, the maximum linear pipe length allowed is still 50 feet (15.2m).

Term

Description

Pipe

Single-wall galvanized steel pipe, 24 gauge

minimum (either insulated or non-insulated)

 

Joint

Permanent duct tape or aluminum tape

Sealing

 

 

 

Table 4. Required Combustion Air Piping Material.

The connection for the intake air pipe is on the filter box. The heaters may have venting and combustion air ducting attached to the top or the back. They are shipped with the connections at the top. For attaching either or both pipes to the back, the mounting flanges are reversible by removing the mounting screws and orienting the flanges in the desired position. Replace the screws after positioning flanges. Run a bead of silicone around the collar and slide the pipe over the collar. Secure with sheet metal screws.

In addition to air needed for combustion, air shall also be supplied for ventilation, including all air required for comfort and proper working conditions for personnel. The Copper Brute II loses less than 1 percent of its input rating to the room, but other heat sources may be present.

Figure 2. Combustion Air and Vent Through Roof.

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Bradford-White Corp BWCV warranty Internet Version for Reference Only, Intake Combustion Air