What is BTU per hour?
BTU per hour is a unit of power used to measure the heating or cooling capacity of HVAC equipment. It is the standard rating system for air conditioners, furnaces, and heat pumps in the United States.
Real-world uses
BTU per hour is the standard power unit for rating furnaces, air conditioners, heat pumps, and boilers in the United States. A residential central air conditioner might be rated at 24,000–60,000 BTU/h. In casual use, the "/h" is often dropped, so "12,000 BTU air conditioner" actually means 12,000 BTU/h.
History
BTU/h became the standard power unit for the US HVAC industry during the post-World War II residential building boom, as central air conditioning and forced-air heating became widespread. Industry standards bodies such as AHRI codified BTU/h ratings for equipment comparison.
Common mistakes
Dropping the "/h": confusing BTU (energy) with BTU/h (power) is extremely common in HVAC contexts. A unit absorbing 12,000 BTU in one hour is operating at 12,000 BTU/h of capacity. Also, 1 ton of refrigeration = 12,000 BTU/h, which can cause confusion in capacity comparisons.
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 BTU 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 BTU per hour = 0.00008333 ton of refrigeration
1 ton of refrigeration = 3,516.85284 watt
How to convert BTU per hour to ton of refrigeration
To convert BTU per hour to ton of refrigeration, multiply the value by 0.00008333.
To convert ton of refrigeration back to BTU per hour, multiply by 12,000.
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: BTU per hour to ton of refrigeration
| BTU per hour | ton of refrigeration |
|---|---|
| 0.1 | 0.00000833 |
| 0.5 | 0.00004167 |
| 1 | 0.00008333 |
| 2 | 0.00016667 |
| 5 | 0.00041667 |
| 10 | 0.00083333 |
| 25 | 0.00208333 |
| 50 | 0.00416667 |
| 100 | 0.00833333 |
| 250 | 0.02083333 |
| 500 | 0.04166667 |
| 1,000 | 0.08333333 |
Common values
| BTU per hour | ton of refrigeration | |
|---|---|---|
| LED light bulb | 34.12141635 BTU per hour | 0.00284345 ton of refrigeration |
| Desktop computer | 1,023.64249054 BTU per hour | 0.08530354 ton of refrigeration |
| Microwave oven | 3,412.14163513 BTU per hour | 0.28434514 ton of refrigeration |
| Small car engine | 255,910.62263498 BTU per hour | 21.32588522 ton of refrigeration |
| Wind turbine (large) | 10,236,424.90539923 BTU per hour | 853.03540878 ton of refrigeration |
Available Power units
More BTU per hour conversions
- Convert BTU per hour to watt
- Convert BTU per hour to kilowatt
- Convert BTU per hour to horsepower (mechanical)
- Convert BTU per hour to megawatt
- Convert BTU per hour to gigawatt
- Convert BTU per hour to milliwatt
- Convert BTU per hour to microwatt
- Convert BTU per hour to kilocalorie per hour
- Convert BTU per hour to ton of refrigeration
Assumption: horsepower values use mechanical horsepower.