Of the following, centrifugal chillers are best described as?

• A. High tonnage, low pressure machines
• B. Low tonnage, high pressure machines
• C. High efficiency, high pressure machines
• D. Medium tonnage, medium pressure machines

Answer: (A)

Centrifugal chillers are designed for very large cooling loads and use a high-volume, low-pressure compressor. They move large amounts of refrigerant with each revolution, which means they operate at relatively low discharge pressures compared to other high-capacity compressors. That combination—high tonnage capability while keeping pressures relatively low—makes centrifugal chillers the go-to choice for big central plants or buildings with substantial cooling demands. The other descriptions don’t fit as well because they imply smaller capacity, higher pressures, or emphasize efficiency in a way that isn’t the defining trait of centrifugal chillers.