11
Circulation Airflow Adjustments
The controls include a variable speed motor interface board. The
ADJUST tap can be used to raise (+) or lower (-) the airflow by
15%.
Heating and Cooling Airflows
The packaged units are factory set for the correct heating and
cooling airflows. However, airflow changes can be made by
moving the position of the HEAT and COOL taps. See Blower
Speed Chart (Variable Speed Motor) for Heat Pump and Cooling
Only Models.
Continuous Blower
The comfort level of the living space can be enhanced when
using this feature by allowing continuous circulation of air
between calls for cooling or heating. The continuous circulation
of air occurs at half the full cooling airflow rate. To use this
feature, place the thermostat fan switch into the ON position.
Cooling Airflow Ramp Up
At the beginning of a call for cooling, the blower will run at 80%
of full airflow for 7
¹⁄₂
minutes. This improves the system’s
moisture removal and saves blower power during cooling start.
Reduced Airflow Operation (Dehumidification)
For situations where humidity control is an issue, the variable
speed motor can be connected to operate at a 25% reduction in
the normal airflow rate. The variable speed motor interface board
provides a connection for a humidistat on the HUM terminal.
When a humidistat is connected, the dehumidifier resistor on the
interface must be cut. The humidistat should be wired to open
during high humidity, which will reduce blower airflow.
ADJUST, HEAT, and COOL Taps and Dehumidify Resistor
SYSTEM MAINTENANCE
■
Leaves and other large obstructions should be removed from
the heat pump surfaces without damaging the fin surface of
the coil.
■
Routinely clean or change the indoor air filter. Should the
indoor coil become dirty, thus restricting airflow, call a
qualified service person to clean the coil surface.
■
An annual inspection by a qualified person should be
performed to ensure continued quality performance.
A. Dehumidify LED
B. Dehumidify resistor
DEHUMIDIFY
CUT TO ENABLE
COOL
HEAT
ADJUST
NORM
A
B
C
D
A
B
C
D
(+)
(–)
TEST
D1
A
B
Blower Speed Chart (Variable Speed Motor) for Heat Pump and Cooling Only Models
Model
Nominal
Cooling
kBtu
Heating
Size kW
Motor HP
ADJUST
Setting
HEAT
Setting
COOL
Setting
CFM A
CFM B
CFM C
CFM D
24
5-10
¹⁄₃
NORM
B
B
1,000
800
600
900
30
5-10
¹⁄₃
NORM
A
A
1,000
800
600
900
36
5-15
¹⁄₂
NORM
A
A
1,200
1,000
800
1,100
42
5-20
³⁄₄
NORM
C
C
1,800
1,600
1,400
1,200
48
5-20
³⁄₄
NORM
B
B
1,800
1,600
1,400
1,200
60
5-20
³⁄₄
NORM
A
A
1,800
1,600
1,400
1,200
