Manual 2100-461
Page
5
FILTERS
A 1-inch throw away filter is suppled 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 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 the 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
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.
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 11 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 1-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
3 feet 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.
Any grille that meets the 5/8 inch louver criteria may be
used. It is recommended that Bard Return Air Grille Kit
RG-2 through RG-5 or RFG-2 through RFG-5 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.
CAUTION
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 inches.
FIGURE 2
FRESH AIR DAMPER ASSEMBLY
MIS-938
