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Manual 2100-581D
Page
5 of 26
DUCT WORK
All duct work, supply and return, must be properly sized
for the design airflow 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 Maximum ESP of operation Electric Heat Table 7.
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.
Models W17 – W24 are approved for 0" clearance to the
supply duct. For model series W30, W36, W42, W48,
W60 and W70, a 1/4" clearance to combustible material
for the first 3' of duct attached to the outlet air frame is
required. See Wall Mounting Instructions and Figures 3
and 4 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".
Any grille that meets with 5/8" 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. 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.
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 1" throwaway filter is standard with each unit. The
filter slides into position making it easy to service. This
filter can be serviced from the outside by removing the
filter access panel. A 1" washable filter and 2" pleated
filter are also available as optional accessories. The
internal filter brackets are adjustable to accommodate
the 2" filter by bending two (2) tabs down on each side
of the filter support bracket.
FRESH AIR INTAKE
All units are built with fresh air inlet slots punched in
the service door.
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 1).
All capacity, efficiency and cost of operation
information 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
A plastic drain hose extends from the drain pan at
the top of the unit down to the unit base. There are
openings in the unit base for the drain hose to pass
through. In the event the drain hose is connected to
a drain system of some type, it must be an open or
vented type system to assure proper drainage.
FIGURE 1
Fresh Air Damper Assembly