Bard WWC2 Wall Curb Instruction Manual

SINCE 1914
Climate Control Solutions

SUPPLEMENTAL INSTRUCTIONS

Wall Curb WWC2

WARNING
For use on non-combustible walls only.
Do not install on combustible walls.
Installation on combustible walls can result in fire.
See INSTALLATION Step 7 on page 3.

Overview

WWC2 wall curb products are an optional accessory that can be installed between the Bard wall mount product and an exterior wall surface to replace equipment on an existing building or new construction projects. The WWC2 wall curb in this manual provides unit upgrade options with minimal wall modifications. Typical unit upgrades  include replacement of older 1.5 to 2 ton units or older HVAC equipment with new Bard 2.5 and 3 ton wall mount products.
Curb Construction
WWC2 curb models are available in Beige (-X), White (-1) and Buckeye Gray (-4). Curb model numbers will be followed by the color code when ordering. Painted cabinet  construction is comprised of 20 gauge zinc coated steel. Parts are cleaned, rinsed, sealed and dried before a polyurethane primer is applied. The cabinet coating is completed  with a baked on textured enamel. The resulting finish is designed to withstand 1000 hours of salt spray tests per ASTM B117-03. All curb models in this manual are shipped  packaged in a flat box and assembly is required before use.

WWC2-* Curb Information Chart

Curb Model| New Unit Model
Using Curb| New Unit Connections| Curb Dimensions| Application
Supply| Return| Supply and
Return| Height| Width| Depth| Downsize Existing Unit*
WWC2-| W18A, W18L,
W24A, W24L,
W18H, W24H| 7.88″
x
19.88°| 11.88′
x 19.88′| 20.56°| 71.00″| 33.13″| 8.07°| WA30, WL30, W30A, W3OL,  WA36, WL36, W36A, W36L,  WH30, W3OH, WH36, W36H,  SH26, SH31

• X = Beige, 1 = White, 4 = Gray
  ** Unit downsizing will require relocation of lower partition

The curb is insulated with an anti-microbial flame/ smoke resistant non- fiberglass cotton material. Middle partitions are used in all curb designs that seal and separate the return and supply air paths. The curb does not include a back panel, and the back of the curb will be open to the wall surface. Sealing the back of the curb to the wall surface is required to avoid water infiltration and air leakage from the supply and return air path.
Fasteners required to attach the Bard wall-mount unit to the curb are supplied from the factory. These include carriage bolts and Keps nuts that will be used to install the unit to the curb. A foam seal is provided between the unit flanges and curb front surface.
Fasteners required to attach the curb to the wall are field supplied and are specific to wall construction. Installation and seismic requirements must follow all national, state and local codes. Review the wall mount installation instructions and all other documentation provided with the wall-mount unit for further guidelines before installing this product.
Basic Curb Use and Pre-Installation Procedures
It is important to calculate the total unit duct static of the installation. If the wall openings or ductwork is for existing equipment, it is important to review the total static pressure the new Bard wall mount will operate at when used. Typical static limitations are .5” WC for standard wall-mount units. In addition, as airflow amounts increase when selecting a new larger cooling capacity unit, duct statics also increase. A professional contractor or engineer must review the duct static of the installation and compare the results with the unit performance data provided in the specifications and user manuals of the new Bard wall mount.
Before installing the wall curb, inspect the site. The supply opening of the new wall-mount unit that will use the wall curb must be aligned with the supply wall opening. A stub duct will be used to transition between the new unit supply opening and the existing wall supply to avoid air leakage and meet any requirements for supply clearances provided in the wall mount installation instructions. Note electrical entrances for the new wall mount product that may require rerouting wiring for power and the thermostat. Review all electrical requirements of the new wall-mount unit including voltage, phasing and wire and breaker sizes. It is important to follow all national, state and local electrical codes. Review the wall surface where the new wall-mount unit is to be installed. The wall surface needs to be flat to allow the curb to be sealed to the wall. Light corrugated surfaces may need to have siding trimmed and framed. Heavy corrugations may require a plate that is sealed to the wall. Verify the wall structure will support the weight of the new wall-mount unit and the curb. Review any obstructions on the wall that may interfere with curb installation, and make sure the unit has adequate ground clearance per the instructions for the new wall mount product.

Installation

Installer Notes

• New Bard wall mount W18 and W24 models are 74″ tall and will overhang the bottom of the WWC2 curb by 4″.
• When using the WWC2 curb to install a new Bard wall mount on an existing wall where a larger W30, W36, SH26 or SH31 wall-mount unit was used, verify the return area  of the sleeve is sealed to avoid outdoor air infiltration. Be sure to caulk unused fastener holes in curb right and left sides and seams that can cause air leakage.

Hardware items included:

• Twelve (12) 1″ Bolts
• Thirty two (32) Screws
• Twenty four (24) Washers
• Twelve (12) Lock Nuts

Field-supplied tools needed for installation:

• Appropriate personal protection equipment, including gloves and safety glasses
• 5/16″ nut driver
• 1/2″ (13mm) wrench or deep well socket
• Safe method of lifting equipment
• Outdoor-rated silicone caulk
• Field-supplied wall fasteners
  See page 9 for a replacement parts breakdown.

Installation Procedure

1. Assemble wall curb per Figure 1 on page 4.

2. Attach curb to wall first (see Figure 2 on page 5).
   The back flanges for attaching to the building wall are formed so they will line up with the mounting pattern of original 2-ton Bard units, and so the weight will bear on  the wall’s original structural design. Ensure the installed assembly is square by measuring corner to corner.

3. Because the new curbs (and air conditioners) are longer than the original units, one or two additional fasteners should be added to the wall near the bottom of the curbs.  Fasteners for attaching the curb to the wall are not included in the kit. 5/16″ diameter fasteners of appropriate length and type for wall construction should be used.

4. When installation requirements are such that the original mounting holes on the wall cannot be used, or the unit(s) must be shifted left or right for some reason, they should be kept as centered as reasonably possible over the supply and return air openings in the wall.

5. Lift unit into position and support while the supplied bolts, washers and nuts are installed fastening the unit to the curb (see Figure 2).

6. Caulk the flanges of the wall curb where they meet the structure. Caulk the top of the unit where it meets the wall curb.

7. WARNING! Supply duct to be field supplied and connected from the unit duct flanges to the building’s wall—maintaining all required clearances for the basic HVAC  unit. Refer to unit instructions and serial plate for required clearances.

FIGURE 1
Assembly of Wall Curb

FIGURE 2
Attaching Wall Curb to Unit
NOTE: Assemble curb and attach to wall before bolting unit to curb.

FIGURE 3
Mark Wall for WWC2 Wall Curb
CENTER UNIT SUPPLY OVER WALL SUPPLY

FIGURE 4
Dimensional Detail of Wall Curb

Dimensions (Inches)

Model| A| B| C| D| E| F
WWC2| 8.| 33.| 71.00| 13.| 33.00| 25.

Replacement Parts

• X = Beige, 1 = White, 4 = Gray

Bard Manufacturing Company, Inc.
Bryan, Ohio 43506
www.bardhvac.com
Manual: 7960-931A
Supersedes: 7960-931
Date: 10-31-22

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