AAON F-060 - Manual (Page 19)

19
service of the air handling unit with
the placement of the check valve.
b. For horizontal discharge units.
Connect the hot gas line from the
outdoor unit to the upper stub-out
connection of the reheat coil.
Connect the check valve (shipped
loose) to the lower stub-out in a
direction so that the refrigerant is
leaving the bottom side of the reheat
coil. Be sure to not block access for
service of the air handling unit with
the placement of the check valve.
2. After installing the check valve, mount
the receiver (shipped loose). The
receiver tank must be mounted
horizontally for proper operation. The
receiver may be mounted on the air
handling unit or at a convenient location
near the air handling unit. Be sure to not
block access for service of the air
handling unit with the placement of the
receiver.
3. After mounting the receiver, run a liquid
line from the discharge of the check
valve to the receiver tank through a tee
connection. Run a liquid line from the
condenser, through a check valve to the
other side of the tee. Note check valve in
condenser liquid line is not used on heat
pump models. (See Refrigerant Piping
Section to determine acceptable line
size, location of components and to see a
diagram depicting the finished line
piping.)
4. After installing the receiver tank, run a
liquid line from the receiver outlet to the
TXV. (See Refrigerant Piping Section to
determine acceptable line size and to see
a diagram depicting the finished line
piping.)
5. After completing the reheat and liquid
lines, run a Suction line from the
evaporator outlet to the outdoor unit
shutoff valve (See Refrigerant Piping
Section to determine acceptable line
size.)
6. After completing the refrigerant piping
installation, install the supply air
temperature sensor (shipped loose) 18”
from the leaving air outlet from the air
handling unit.
7. After installing the supply air
temperature sensor, check that the reheat
supply air temperature setpoint is
correctly set on the control board. This
temperature should be set to the desired
space temperature when the unit is in
cooling mode. If that temperature is
unknown at the time of installation, set
the setpoint to 72
°F.
The reheat system provides for “neutral”
(neither hot nor cold) air to the space so that
the unit can dehumidify the air without over
cooling or over heating the space. The
desired leaving air temperature is set on the
control board in the unit. The factory
suggests a setpoint of 72
°F for most
applications; however, the setpoint is
adjustable for more specific applications or
differing comfort levels. The setpoint should
be set for the desired temperature in the
space during cooling mode. During
dehumidification mode the cooling coil
operates and the modulating valve in the
reheat system meters the amount of hot
refrigerant being directed to the reheat coil
so that the cooled and dehumidified air is
reheated, to the setpoint provided on the
control board, to a room neutral temperature.
This temperature setpoint and method of
dehumidification allows for the home to be
dehumidified even when there is not a need
for cooling in the space.
Note: Systems with the modulating hot gas
reheat option will require refrigerant to be
field added because of the additional
refrigerant components and piping
associated with the system.