10 APC NetworkAIR AFX Series: Standard Features
Each refrigeration system includes:
•Thermal expansion valve with equalizer
•High and low pressure switches
•Sight glass with moisture indicator
•Filter drier
•Liquid line solenoid valve
Cooling coil The AFX utilizes dual distributors on one circuit of the refrigeration system.
During dehumidification the smaller distributor is turned off effectively
reducing the active circuits of the evaporator coil. During this mode of
operation the evaporating temperature is decreased, resulting in a lower coil
surface temperature. This reduction of the coil temperature decreases the
sensible heat ratio of the coil allowing a greater percentage of moisture
removal. Additionally the warmer air leaving the inactive circuits of the
evaporator coil blends with the near saturated air from the active circuits
raising the dry bulb temperature of the blended air well above saturation.
Condenser Water-and glycol-cooled systems employ a brazed plate condenser that uses
the latest heat transfer technology. Type 316L stainless plates are brazed
together in a vacuum furnace and comply with ASME pressure vessel code.
Pressure rating is 450 psi (3100 kPa).
Air filter The filtration of conditioned air is extremely vital to maintaini ng the clean,
particle-free environment required by electrical equipment. The AFX Series
uses 30% efficient (ASHRAE 52.1–92), 4" (102 mm) deep filters, with full
depth filter pleats. In addition to high filtration properties, these filters
produce a lower pressure drop than standard filters so less energy is required
during normal operation. Filters are easily replaced from the top on
downflow units and from the front on upflow units.
Water-regulating valves
The water-and glycol-cooled systems maintain proper performance by
sensing refrigerant discharge pressure and regulating the amount of water or
glycol supplied to the condenser. Two-way and three-way valves are
available. The standard valve pressure rating is 150 psi (1030 kPa).
Airflow sensor The air proving switch is continuously monitored by the microprocessor.
Upon detection of a loss of air flow the microprocessor will deactivate:
cooling, heating, humidification and dehumidification. After the air flow has
been restored for a predetermined period of time the microprocessor will
reactivate the functions as needed.
Clogged filter alarm An adjustable air pressure differently switch senses the pressure drop across
the filters. Upon sensing an excessive pressure drop, the switch activates the
alarm circuit of the microprocessor and displays a clogged filter message
simultaneously with an audible signal.