What is kilocalorie per hour?
Kilocalorie per hour is a unit of power expressing energy transfer as dietary calories per hour. It is used in nutrition and exercise physiology to express the rate of energy expenditure during physical activity.
Real-world uses
Kilocalories per hour (kcal/h) are used in exercise physiology to express metabolic power output (a brisk walk burns about 300 kcal/h, cycling about 500–800 kcal/h), and in HVAC engineering in Asia and Latin America to rate heating and cooling equipment, where it bridges nutritional and thermal engineering contexts.
History
The kilocalorie per hour emerged as a natural unit at the intersection of nutritional science and physiology, where metabolic rates had long been expressed in food energy per unit time. In HVAC contexts, it provided a familiar scale for countries where kilocalories were the customary energy unit before SI adoption.
Common mistakes
Confusing kcal/h (power) with kcal (energy). A person burning 300 kcal/h for 2 hours has expended 600 kcal, not 300 kcal. Also, mixing up kcal/h with kJ/h: 1 kcal/h = 4.184 kJ/h ≈ 1.163 W.
What is ton of refrigeration?
A ton of refrigeration is a power unit measuring the heat removal capacity of cooling systems, equal to 12,000 BTU per hour. It is the standard capacity rating for commercial and industrial air conditioning units in the United States.
Real-world uses
The ton of refrigeration (TR) is used for rating commercial and industrial cooling systems, chillers, and large-scale HVAC equipment. A small commercial building might need a 20–100 TR chiller. Data centres measure cooling capacity in TR. One TR = 12,000 BTU/h = approximately 3.517 kW.
History
The ton of refrigeration originated in the 19th century ice trade, when mechanical refrigeration systems were judged by their ability to replace ice delivery. One ton was defined as the cooling equivalent of melting one ton of ice per day. As mechanical refrigeration displaced natural ice by the early 20th century, TR became a standard industrial cooling unit.
Common mistakes
Confusing refrigeration tons with metric tons of mass—they are completely unrelated. Also, the "ton" in TR originated from the cooling power needed to melt one short ton (2,000 lb) of ice in 24 hours, not from any mass being cooled.
When is this conversion used?
Converting kilocalorie per hour to ton of refrigeration is useful in the power domain when comparing values across different measurement standards or applying formulas that require a specific unit.
Worked examples
1 kilocalorie per hour = 0.00033069 ton of refrigeration
1 ton of refrigeration = 3,516.85284 watt
How to convert kilocalorie per hour to ton of refrigeration
To convert kilocalorie per hour to ton of refrigeration, multiply the value by 0.00033069.
To convert ton of refrigeration back to kilocalorie per hour, multiply by 3,023.94913156.
Measurement standards
The watt is the SI derived unit of power, defined as one joule per second (kg·m²/s³). Horsepower remains in widespread informal use, particularly in the automotive industry, but has no single universal definition across regions.
Did you know?
The human body at rest produces about 80 watts of power — roughly enough to keep an incandescent light bulb glowing. During intense exercise, a trained cyclist can sustain over 400 watts, and elite sprinters briefly exceed 2,000 watts.
Quick reference: kilocalorie per hour to ton of refrigeration
| kilocalorie per hour | ton of refrigeration |
|---|---|
| 0.1 | 0.00003307 |
| 0.5 | 0.00016535 |
| 1 | 0.00033069 |
| 2 | 0.00066139 |
| 5 | 0.00165347 |
| 10 | 0.00330693 |
| 25 | 0.00826733 |
| 50 | 0.01653467 |
| 100 | 0.03306934 |
| 250 | 0.08267335 |
| 500 | 0.1653467 |
| 1,000 | 0.33069339 |
Common values
| kilocalorie per hour | ton of refrigeration | |
|---|---|---|
| LED light bulb | 8.59845228 kilocalorie per hour | 0.00284345 ton of refrigeration |
| Desktop computer | 257.95356836 kilocalorie per hour | 0.08530354 ton of refrigeration |
| Microwave oven | 859.84522786 kilocalorie per hour | 0.28434514 ton of refrigeration |
| Small car engine | 64,488.39208942 kilocalorie per hour | 21.32588522 ton of refrigeration |
| Wind turbine (large) | 2,579,535.68357696 kilocalorie per hour | 853.03540878 ton of refrigeration |
Available Power units
More kilocalorie per hour conversions
- Convert kilocalorie per hour to watt
- Convert kilocalorie per hour to kilowatt
- Convert kilocalorie per hour to horsepower (mechanical)
- Convert kilocalorie per hour to megawatt
- Convert kilocalorie per hour to gigawatt
- Convert kilocalorie per hour to milliwatt
- Convert kilocalorie per hour to microwatt
- Convert kilocalorie per hour to BTU per hour
- Convert kilocalorie per hour to ton of refrigeration
Assumption: horsepower values use mechanical horsepower.