Bard WA121 Duct Work, Filters, Fresh AIR Intake, Condensate Drain, Fresh AIR Damper

DUCT WORK

All duct work, supply and return must be properly sized for the design air flow requirement of the equipment. Air Conditioning Contractors of America (ACCA) is an excellent guide to proper sizing. All duct work or portions thereof not in the conditioned space should be properly insulated in order to both conserve energy and prevent condensation or moisture damage.

Refer to Table 9 for maximum static pressure available for duct design.

Design the duct work according to methods given by the Air Conditioning Contractors of America (ACCA). When duct runs through unheated spaces, it should be insulated with a minimum of one inch of insulation. Use insulation with a vapor barrier on the outside of the insulation. Flexible joints should be used to connect the duct work to the equipment in order to keep the noise transmission to a minimum.

Ducts through the walls must be insulated and all joints taped or sealed to prevent air or moisture entering the wall cavity.

Some installations may not require any return air duct. It is recommended that on this type of installation that a filter grille be located in the wall. Filters must be of sufficient size to allow a maximum velocity of 400 FPM.

NOTE: If no return air duct is used, applicable installation codes may limit this cabinet to installation only in a single story structure.

FILTERS

A one inch throwaway filter is supplied with each unit. The filter slides into position making it easy to service. This filter can be serviced from the outside by removing the service door. A 2-inch pleated filter is also available as an optional accessory. The internal filter brackets are adjustable to accommodate the 2-inch filter by bending the metal tabs holding the 1-inch filter down. There are two tabs on each side of the filter.

FRESH AIR INTAKE

All units are built with fresh air inlet slots punched in the service panel.

If the unit is equipped with a fresh air damper assembly, the assembly is shipped already attached to the unit. The damper blade is locked in the closed position. To allow the damper to operate, the maximum and minimum blade position stops must be installed. See Figure 2.

All capacity, efficiency and cost of operation information as required for Department of Energy “Energyguide” Fact Sheets is based upon the fresh air blank-off plate in place and is recommended for maximum energy efficiency.

The blank-off plate is available upon request from the factory and is installed in place of the fresh air damper shipped with each unit.

CONDENSATE DRAIN

This unit employs an automatic condensate disposal system consisting of a base drain pan, drain valve and fan blade with slinger ring. A plastic drain hose extends from the evaporator drain pain at the top of the unit to the base drain pan at the bottom. At temperatures above 40°, the drain valve located between the condenser coil and fan shroud is closed allowing water to build up in the base to a height of 5/8" to 3/4". The fan blade with slinger then rotates in this water and throws the water onto the condenser coil. This disposes of the water by evaporating it on the hot condenser.

At temperatures below 40°, the drain valve opens draining the base pan and preventing freeze ups that could damage the coil or fan blade.

FIGURE 2

FRESH AIR DAMPER

Manual 2100-234I

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