What is in this article?:
Recent technology innovations, combined with advances in manufacturing practices, have resulted in considerable improvements in air-cooled-chiller performance.
The Air-Cooled Advantage
Air-cooled screw chillers offer high performance, particularly at partial load. Their compressors typically are modulating (slide valve or VFDs), rather than stepped, which yields more accurate control. Advantages of air-cooled chillers include:
• Positive-displacement compression with no surge.
• No cooling towers.
• Avoidance of city water costs.
• Avoidance of water waste.
• Avoidance of chemical costs.
• In the event of a natural disaster, no water issues.
• No condenser pumps and piping.
• Reasonable maintenance costs.
• Saved mechanical-room space.
• Simpler control (no tower bypass) and operation (no tower freezing) in cold climates.
Table 1 compares two air-cooled chillers: one based on 1998 efficiency levels, the other one of today’s most efficient models. Modern air-cooled chillers can perform at full-load efficiencies up to 17-percent higher and part-load efficiencies up to 37-percent higher.