Closed Loop Cooler/Boiler Systems - WaterFurnace AT022C/D Installation And Maintenance Manual

PREMIER 2 SINGLE-SPEED INSTALLATION AND MAINTENANCE MANUAL
FREEZE PROTECTION
Set the freeze protection switch SW2-2 on the printed circuit board for applications using a
closed loop antifreeze solution to "LOOP". On applications using an open loop/groundwater
system, set to "WELL" (the factory setting).
CONDENSATE DRAIN
On vertical units, the internal
condensate drain assembly consists of a
drain tube which is connected to the
drain pan, a 3/4" PVC female adapter
and a flexible connecting hose. The
female adapter may exit either the front
or the side of the cabinet. The adapter
should be glued to the field-installed
PVC condensate piping. On vertical
units, a condensate hose is inside all
cabinets as a trapping loop; therefore,
an external trap is not necessary. On
horizontal units, a copper stub is
provided for condensate drain piping
connection. An external trap is required
(see Figure 5B). If a vent is necessary,
an open stand pipe may be applied to a
tee in the field-installed condensate
piping.
AIR COIL
To obtain maximum performance, the air coil should be cleaned before start-up. A 10 percent
solution of dishwasher detergent and water is recommended for both sides of the coil; a thorough
water rinse should follow.
COOLER/BOILER
CAUTION:
Water piping exposed to outside temperatures may be subject to freezing
The water loop is usually maintained between 60°F and 90°F (Premier 2 units allow 25°F -
110°F EWT) for proper heating and cooling operation. This is accomplished with a cooling tower
and a boiler (see Figure 6). To reject excess heat from the water loop, use a closed circuit
evaporative cooler or an open type cooling tower with a secondary heat exchanger between the
tower and the water loop. If an open type cooling tower is used without a secondary heat
exchanger, continuous chemical treatment and filtering of the water must be performed to ensure
the water is free from damaging materials. The water lines should be routed so as not to interfere
with access to the unit. Flexible hose connections should be used to minimize vibration transmis-
sion.
Before final connection to the unit, the supply and return hose kits must be connected
together and the system flushed to remove dirt, piping chips and other foreign material. Normally,
a combination balancing and close-off (ball) valve is installed at the return and a rated gate or
ball valve is installed at the supply. The return valve can be adjusted to obtain the proper water
flow. The valves allow the unit to be removed for servicing.
Figure 5A - Unit Pitch for Drain
Figure 5B - Horizontal Drain Connection
Clear PVC Hose *
Copper Tube Stub
Plastic Hose Clamp *
*Included with unit
1/4'' Pitch
Drain
Vent (if needed)
3/4" Barb to
Glue Adapter *
3/4" PVC
1/8" per foot
1.5"
1.5"
.
Closed Loop
Cooler/Boiler
Systems
5