36
and PVC is the only acceptable means of cleaning
the evaporative condenser. A proper water
treatment program should reduce cleaning needs.
EVAPORATIVE CONDENSER -
WATER QUALITY
Recirculating Water Quality Guidelines:
Table 6 - Water Quality
Cycles of concentration (the ratio of dissolved
solids in recirculated water to dissolved solids in
make-up), must be determined and monitored
frequently by a competent water treatment expert.
To limit cycles of concentration to maintain the
above guideline, it is necessary to “bleed” a
certain portion of the recirculated water. This is
achieved automatically with a solenoid valve
actuated by a conductivity meter set at the desired
conductivity corresponding to the desired cycles
of concentration. These are guidelines and even
though these individual values are met, under
certain conditions the water quality can be
aggressive. For example, water with very low
alkalinity and levels of chlorides and sulfates
approaching maximum recommended levels can
be corrosive.
Mechanical Cleaning:
Do not attempt to mechanically clean the copper
tubing in the evaporative condenser. Do not use
wire brushes or any other mechanical device on
the copper tubing. Severe damage may result.
Contact your water treatment expert for
recommendations
on
chemical
cleaning
procedures.
Parts:
Contact your local AAON Representative for
factory authorized parts. Orders must include the
Serial Number from the product nameplate OR
visit
www.aaonparts.com
for more information.
AIR-COOLED CONDENSER
The air-cooled condenser section rejects heat by
passing outdoor air over the fin tube coils for
cooling of the hot refrigerant gas from the
compressors. The heated air will discharge from
the top of the section through the axial flow fans.
Inspect the condenser coils annually to ensure
unrestricted airflow. If the installation has a large
amount of airborne dust or other material, clean
the condenser coils with a water spray in a
direction opposite to airflow. Care must be taken
to prevent bending of the aluminum fins on the
copper tube.
E-Coated Coil Cleaning
Documented routine cleaning of e-coated coils is
required to maintain coating warranty coverage
for fin and tube and microchannel coils. See the
AAON E-Coated Coil Maintenance Record
sheet.
Surface loaded fibers or dirt must be removed
prior to water rinse to prevent restriction of
airflow. If unable to back wash the side of the coil
opposite of the coils entering air side, then
surface loaded fibers or dirt must be removed
with a vacuum cleaner. If a vacuum cleaner is not
available, a
soft non-metallic
bristle brush may
be used. In either case, the tool must be applied
in the direction of the fins. Coil surfaces can be
easily damaged (fin edges bent over) if the tool is
applied across the fins.
Use of a water stream, such as a garden hose,
against a surface loaded coil will drive the fibers
Electric shock hazard. Shut off all
electrical power to the unit to avoid
shock hazard or injury from rotating
parts.
WARNING
