Unloaders are used to control capacity on commercial compressors.

• A. True
• B. False
• C. Not commonly used
• D. Only in residential

Answer: (A)

Unloaders control capacity by reducing the number of cylinders (or the amount of displacement) that actively compress in a multi-cylinder commercial compressor. When demand is lighter, some cylinders are unloaded, so only the remaining cylinders work, allowing the compressor to meet partial loads without running at full capacity. This improves efficiency, reduces energy use, and minimizes cycling wear. While other compressors may use different modulation methods, unloaders are a common and valid way to control capacity in commercial units, making the statement true.