Convert British Thermal Units to Horsepower-Hours
Convert British Thermal Units (BTU) to Horsepower-Hours (hp·h) instantly and accurately.
Conversion Formula
hp·h = BTU × 0.0003930147789
About British Thermal Units
A British Thermal Unit (BTU) - the heat to raise 1 lb of water by 1°F - equals exactly 1,055.05585262 J. It dominates US HVAC: room air conditioners are rated in BTU/h (5,000-24,000 BTU/h = 1.5-7.0 kW); one ton of refrigeration is exactly 12,000 BTU/h. Natural gas is billed in therms (100,000 BTU) in the US. Higher heating values: natural gas ~1,020-1,050 BTU/ft³; No. 2 fuel oil ~138,700 BTU/US gal; propane ~91,500 BTU/US gal. 1 BTU = 1,055.06 J = 252.164 cal = 0.29307 Wh.
About Horsepower-Hours
A horsepower-hour (hp·h) is the energy from one mechanical horsepower (745.6999 W) for one hour - exactly 2,684,519.54 J ≈ 2.685 MJ. James Watt coined the horsepower to compare his steam engines with mine horses; billing in hp·h preceded the kilowatt-hour tariff. The metric horsepower (PS = 75 kgf·m/s = 735.499 W) gives a slightly smaller metric-hp·h = 2,647,795 J, used in European and Japanese engine datasheets. Today the hp·h appears in marine engineering logs, mining energy accounting, and vintage industrial equipment. 1 hp·h = 2.6845 MJ = 0.74570 kWh = 641.19 kcal.
Quick Reference Table
| British Thermal Units (BTU) | Horsepower-Hours (hp·h) |
|---|---|
| 1 BTU | 0.000393015 hp·h |
| 2 BTU | 0.00078603 hp·h |
| 5 BTU | 0.00196507 hp·h |
| 10 BTU | 0.00393015 hp·h |
| 25 BTU | 0.00982537 hp·h |
| 50 BTU | 0.0196507 hp·h |
| 100 BTU | 0.0393015 hp·h |