Manual 2100-515B
Page
5 of 23
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.
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.
For model series W48, W60 and W70, 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 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.
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. 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.
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.
FILTERS
W48A12, W48L12 & W60A12, W60L12 ONLY
A 1-inch throw away 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 the metal tabs
holding the 1-inch filter down. There are two tabs on
each side of the filter.
NOTE:
W48A13, W48L13, W60A13, W60L13 and
W70A13, W70L13 models require the use of a
return air filter grille.
