Manual
2100-480
Page
7 of 24
FIGURE 2
FRESH AIR DAMPER
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.
A 1/4 inch clearance to combustible material for the
first three feet of duct attached to the outlet air frame is
required. See Wall Mounting Instructions and Figures
4, 5, 6 and 7 for further details.
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.
A metallic return air grille is required with installations
not requiring a return air duct. The spacing between
louvers on the grille shall not be larger than 5/8 inch.
NOTE: If no return air duct is used, applicable
installation codes may limit this cabinet to
installation only in a single story structure.
Any grille that meets with 5/8 inch louver criteria may
be used. It is recommended that Bard Return Air Grille
Kit RG2 through RG5 or RFG2 through RFG5 be
installed when no return duct is used. (RFG filter is not
included; must order separately.) Contact distributor or
factory for ordering information. If using a return air
filter grille, filters must be of sufficient size to allow a
maximum velocity of 400 fpm.
FILTERS
A 1-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 1-inch washable filter and a 2-inch
pleated filter are also available as optional accessories.
The internal filter brackets are adjustable to
accommodate the 2-inch filter by bending down the two
horizontal tabs on each filter bracket.
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.
