Air-Cooled Chiller Units

An air-cooled chiller rejects condenser heat directly to the outdoor air through fans, so it needs no cooling tower, condenser water circuit or plant room. That makes it the most straightforward way to add process cooling to an existing facility, and the usual choice where water is scarce or a cooling-water circuit would be costly to build.

Carnot's air-cooled range spans 2 to 2,000 kW in three series and includes configurations for laser cooling and low-temperature processes.

If the refrigerant strategy is open, Thule offers the widest capacity range; Chemic and ZERO are the options when the F-gas phase-down and low-GWP refrigerants drive the decision.

Air-cooled units are installed outdoors, at ground level or on the roof. Condenser performance depends directly on the ambient temperature, so units are selected for the site's summer design conditions; Thule is designed for stable operation at high ambient temperatures.

Inverter (EC) fans adjust airflow to the actual load and condensing pressure instead of running at full speed. At part load and in cooler weather this reduces fan energy and operating noise.

For outdoor operation in winter, freeze protection for the water circuit — glycol or a heated circuit — is defined at the design stage.

Where process water is needed all year, cold outdoor air can carry part of the load. In winter and the transitional seasons a free-cooling coil pre-cools the return water before it reaches the chiller, and when it is cold enough the compressors can stop entirely. Carnot's free cooling solutions are covered under Dry Cooler and Free Cooling Units.