Convert BTU per Hour to Calories per Hour

Convert BTU per Hour (BTU/h) to Calories per Hour (cal/h) instantly and accurately.

Conversion Formula

cal/h = BTU/h × 251.9957611

About BTU per Hour

One BTU per hour (BTU/h) ≈ 0.2931 W - the dominant HVAC capacity unit in the US and Canada. Room air conditioners are universally rated in BTU/h: 12,000 BTU/h = 1 ton of refrigeration = 3,517 W. Home furnaces range from 40,000-150,000 BTU/h. Office building cooling demand is calculated in BTU/h per ft². Engineers convert: BTU/h × 0.2931 = W; or W × 3.412 = BTU/h. 1 BTU/h = 0.29307 W.

About Calories per Hour

One calorie per hour (cal/h) equals exactly 0.001163 W - the rate of transferring one thermochemical calorie (4.1868 J) per hour. A resting adult generates ~70-80 W ≈ 60,000-70,000 cal/h of heat. The unit appears in European and Asian HVAC standards for small-appliance heat loads and in laboratory calorimetry reporting metabolic activity of small organisms. Calorimetric enzyme assays also express catalytic heat in cal/h per unit enzyme. 1 cal/h = 0.001163 W.

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