506271-01
Page 5 of 14
Issue 0921
The supply and return air duct systems should be designed
for the CFM and static requirements of the job.
They should
not be sized by matching the dimensions of the duct
connections on the unit.
Filters
Filters are not supplied with the unit. Filters must always be
installed ahead of the evaporator coil and must be kept clean
or replaced. Dirty filters will reduce the airflow of the unit.
Filters should be sized in accordance with Table 3.
This unit is equipped with an internal filter clip which is located
in the indoor coil compartment attached to the side of the
unit drain pan.
Gas Piping
Proper sizing of a gas piping depends on the cubic feet per
hour of gas flow required, specific gravity of the gas, and
length of run. National Fuel Gas Code Z223.1 latest edition
should be followed in all cases unless superseded by local
codes or gas company requirements. In Canada, refer to
CAN/CGA B.149.1 & .2 (latest edition).
The heating value of the gas may differ with locality. The
value should be checked with the local gas utility. For
temperature rise of unit, see unit rating plate.
Condensate Drain
This package unit is equipped with a 3/4" FPT coupling for
condensate line connection. Plumbing must conform to local
codes. Use a sealing compound on male pipe threads.
The condensate drain line must be properly trapped and
routed to a suitable drain.
See Figure 3 for proper drain
arrangement. The drain line must pitch to an open drain or
pump to prevent clogging of the line. Seal around the drain
connection with suitable material to prevent air leakage into
the return air system.
Ductwork
Ductwork should be designed and sized according to the
methods in Manual Q of the Air Conditioning Contractors of
America (ACCA).
A closed return duct system shall be used. This shall not
preclude use of economizers or outdoor fresh air intake. It
is recommended that supply and return duct connections at
the unit be made with flexible joints.
When fastening ductwork to the side duct flanges on unit,
insert screws through duct flanges only. Do not insert
screws through the casing. Outdoor ductwork must be
insulated and waterproofed.
CAUTION
Table 2
Minimum Required Surface Area
for Disposable Filters
Typical Condensate Drain Connection
Figure 3
