Catalogue

12 CG-PRC017H-EN
Application Considerations
Unit Location
General
Unobstructed flow of condenser air is essential to maintain chiller capacity and operating
efficiency. When determining unit placement, careful consideration must be given to assure a
sufficient flow of air across the condenser heat transfer surface.Two detrimental conditions are
possible and must be avoided: warm air recirculation and coil starvation. Air recirculation occurs
when discharge air from the condenser fans is recycled back to the condenser coil inlet. Coil
starvation occurs when free airflow to the condenser is restricted.
Condenser coils and fan discharge must be kept free of snow or other obstructions to permit
adequate airflow for satisfactory unit operation. Debris, trash, supplies, etc., should not be allowed
to accumulate in the vicinity of the air-cooled chiller. Supply air movement may draw debris into
the condenser coil, blocking spaces between coil fins and causing coil starvation.
Both warm air recirculation and coil starvation cause reductions in unit efficiency and capacity
because of the higher head pressures associated with them.The air-cooled CGAM chiller offers an
advantage over competitive equipment in these situations. Operation is minimally affected in
many restricted air flow situations due to its advanced Adaptive Control™ microprocessor which
has the ability to understand the operating environment of the chiller and adapt to it by first
optimizing its performance and then staying on line through abnormal conditions. For example,
high ambient temperatures combined with a restricted air flow situation will generally not cause
the air-cooled model CGAM chiller to shut down. Other chillers would typically shut down on a high
pressure nuisance cut-out in these conditions.
Cross winds, those perpendicular to the condenser, tend to aid efficient operation in warmer
ambient conditions. However, they tend to be detrimental to operation in lower ambients due to
the accompanying loss of adequate head pressure. Special consideration should be given to low
ambient units. As a result, it is advisable to protect air-cooled chillers from continuous direct winds
exceeding 10 mph (4.5 m/s) in low ambient conditions.
The recommended lateral clearances are depicted in the close spacing engineering bulletin
available from your local office.
Provide Sufficient Unit-to-Unit Clearance
Units should be separated from each other by sufficient distance to prevent warm air recirculation
or coil starvation. Doubling the recommended single unit air-cooled chiller clearances will
generally prove to be adequate.
Walled Enclosure Installations
When the unit is placed in an enclosure or small depression, the top of the surrounding walls
should be no higher than the top of the fans.The chiller should be completely open above the fan
deck.There should be no roof or structure covering the top of the chiller. Ducting individual fans
is not recommended.