Manual 2100-723
Page
5 of 39
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 the Maximum External Static Pressure (ESP)
of Operation – Electric Heat Only table on page 35.
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" 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.
All model series require a 1/4" clearance to
combustible material for the first 3' of duct attached to
the outlet air frame. See instructions on page 10 and
Figures 13 − 17 (pages 13 – 16) 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 a 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
Kits RG5 or 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
The filters can be serviced from the outside by
removing the front control panel cover (see Figure 1).
Two (2) 20" x 20" x 2" disposable filters come standard
with each unit.
Filter Removal/Installation
1. Remove left filter first by pulling on filter removal
slide (see Figure 2).
2. Slide second filter to the left around the wires and
pull the filter out (see Figure 3).
3. Reverse the order for new filter installation.
NOTE:
When installing new filters, make sure that
airflow arrows on filters point up.
FIGURE 1
Front Control Panel Cover
Front
Control Panel
Cover
FIGURE 3
Removing Second Filter
Switching Filter Sizes
1. To switch from 2" to 1" filters, start by removing
the filter slide and bend the tabs up (see Figures 4
and 5 on page 6).
2. Locate the filter support brackets and remove the
four (4) screws holding them to the top of the
control panel (see Figure 6 on page 6).
Filter
Removal Slide
FIGURE 2
Removing Left Filter
