Manual 2100-738C
Page
15 of 73
Duct Work
Any heat pump is more critical of proper operating
charge and an adequate duct system than a straight air
conditioning unit. All duct work 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. 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.
The QW*S Series heat pump has provisions to attach a
supply air duct to the top of the unit. Duct connection
size is 10" x 25" nominal for QW2S and QW3S models.
Duct connection size is 10" x 30" nominal for QW4S
and QW5S models. The duct work is field supplied
and must be attached in a manner to allow for ease
of removal when it becomes necessary to slide the
unit out from the wall for service. See Figure 9 for
suggested attachment method.
NOTE: Unit cabinet, supply air duct and free blow
plenum are approved for “0” clearance to
combustible material.
The Q-TEC
Series heat pumps are designed for use
with free return (non-ducted) and either free blow
with the
use of QPB Plenum Box or a duct supply air
system.
The QPB plenum box mounts on top of the unit and
has both vertically and horizontally adjustable louvers
on the front discharge grille.
When used with a ducted supply, a QCX cabinet
extension can be used to conceal the duct work above
the unit to the ceiling. This extends 20" above the
unit for a total height above the floor of 10'-7/8". The
unit is equipped with a variable speed indoor blower
motor which increases in speed with an increase in
duct static pressure. The unit will therefore deliver
proper rated airflow up to the Maximum ESP shown in
Table 4 on page 33. However, for quiet operation of
the air system, the duct static should be kept as low as
practical, within the guidelines of good duct design.
Filters
Two 2" pleated filters are supplied with each unit. The
filters fit into a fixed rack.
The filters are serviced from the inside of the building.
To gain access to the filters release the latch on the
circuit breaker door and one 1/4 turn fastener near the
bottom of the door. This door is hinged on the left so it
will swing open.
The internal filter brackets are adjustable to
accommodate 1" filters. The tabs for the 1" filters must
be bent up to allow the 1" filters to slide in place.
Condensate Drain
The condensate drain hose is routed down from the
evaporator drain pan on the right side of the unit into
the compressor compartment. There are three locations
that the drain can exit the cabinet.
If the drain is to be hard plumbed, there is a 3/4" PVC
female adapter located on the cabinet rear panel. In
these installations, the drain tube is to be slipped over
the pipe connection inside of the cabinet; this is how
it is shipped from the factory (see Figure 10C on page
17).
For a stand pipe type of drain, the drain hose can exit
the rear of the cabinet. There is adequate hose length
to reach the floor on the right hand side of the unit
(see Figure 10A on page 16).
NOTE: Whichever type of drain connection is used, a
“P” trap must be formed (see Figure 10A on
page 16).
FIGURE 9
Supply Duct Connections
MODEL
"A"
"B"
QW2S, QW3S
10"
25"
QW4S, QW5S
10"
30"
MIS-2742 A
OF QW UNIT
ROOM SIDE
BE FIELD
SUPPLIED
DUCT FLANGE
"B"
PROVIDED WITH UNIT
"A"
ATTACHMENT
SCREWS TO
SUPPLY DUCT TO
BE FIELD SUPPLIED
