What Is an Air-Cooled Chiller?
An air-cooled chiller cools water or a suitable water-glycol mixture for a process or HVAC system and rejects condenser heat to outdoor air. “Air-cooled” describes the condenser cooling method; it does not mean that the system has no water on the load side.
How the Refrigeration Cycle Works
In the evaporator, refrigerant absorbs heat from the circulating water. The compressor raises refrigerant pressure, while airflow provided by condenser fans removes heat at the condenser coil. The expansion device lowers the pressure and the cycle repeats. Chilled water reaches the loads through the distribution pipework.
Unlike a water-cooled chiller, it does not need a separate condenser-water circuit and, in most applications, a cooling tower. The process-water circuit, pump, filtration and water-quality management remain essential parts of the system.
Where Is It Used?
Applications include plastics, food production, machinery and building air conditioning. It can be suitable where condenser-water infrastructure is unavailable. Outdoor installation capability does not mean that the unit can be placed anywhere without checking its requirements.
Air intake and discharge paths must remain clear, with hot discharge air prevented from recirculating into the condenser. Clearances to walls, roofs, other units and service areas must follow manufacturer instructions. Noise, structural support and vibration also require assessment.
What Determines Required Capacity?
Cooling capacity depends on leaving-water temperature, flow rate, fluid properties and outdoor air temperature. Ratings at different catalogue conditions should not be compared directly. Capacity at the hottest design conditions needs specific verification.
Operation at low ambient temperature does not automatically mean that a unit provides free cooling. Free cooling requires suitable heat exchangers, hydraulics and controls. Any necessary low-ambient operating equipment must also be checked in the product documentation.
Efficient and Reliable Operation
Clean condenser coils, functioning fans and adequate water flow support operating performance. Closing unused branches or adjusting pump speed must not take evaporator flow outside its permitted range.
Evaluate capacity, water-temperature conditions, installation space and operating hours with CEMS Chiller. Correct selection depends on the complete installed system, not simply the unit’s nominal capacity.
This article provides general information. Product selection and operating limits must be based on the relevant model’s technical documentation and project-specific calculations.
