Convert Electrical Horsepower to Ton of Refrigeration
Convert Electrical Horsepower (hp(E)) to Ton of Refrigeration (RT) instantly and accurately.
Conversion Formula
RT = hp(E) × 0.2121214715
About Electrical Horsepower
The electrical horsepower (hp(E)) is defined as exactly 746 W - the US NEMA rounding used on electric motor nameplates. It differs from mechanical hp (745.7 W) by only 0.04%. Every NEMA-rated motor in the US carries a horsepower nameplate: a '5 hp motor' delivers 5 × 746 = 3,730 W. NEC motor branch-circuit sizing tables, overload relay selection, and starter ratings are all based on hp(E). Despite global kW adoption, US industrial motor infrastructure remains standardised in electrical horsepower. 1 hp(E) = 746 W.
About Ton of Refrigeration
One ton of refrigeration (RT) = 12,000 BTU/h ≈ 3,517 W - the cooling rate to freeze 1 short ton (2,000 lb) of water in 24 hours. This follows from water's latent heat: 144 BTU/lb × 2,000 lb ÷ 24 h = 12,000 BTU/h. US residential AC is 1.5-5 tons; a large commercial building 500-2,000 tons; a hyperscale data centre 50,000-100,000 tons. The RT is deeply embedded in North American HVAC catalogs, load calculation software, and contractor pricing. 1 RT = 3,516.85 W.
Quick Reference Table
| Electrical Horsepower (hp(E)) | Ton of Refrigeration (RT) |
|---|---|
| 1 hp(E) | 0.212121 RT |
| 2 hp(E) | 0.424243 RT |
| 5 hp(E) | 1.06061 RT |
| 10 hp(E) | 2.12121 RT |
| 25 hp(E) | 5.30304 RT |
| 50 hp(E) | 10.6061 RT |
| 100 hp(E) | 21.2121 RT |