Horsepower describes the compressor in a chiller, not the cooling delivered. Common sizes run from 1/10 HP to 1 HP. Because efficiency varies with the heat exchanger, refrigerant and coil design, two chillers of the same nominal horsepower can differ by a thousand BTU per hour or more.
Why it matters when you are comparing products
Horsepower is a rough size class, not a performance figure. A 1/2 HP unit rated at 5,750 BTU/h genuinely outperforms a 1/2 HP unit rated at 5,000, despite the identical label.
Where this comes up
- Chillers — Where the same horsepower class covers different real capacities.
Reviewed 2026-08-15