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.

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.

When is this conversion used?

Converting ton of refrigeration to BTU per hour is useful in the power domain when comparing values across different measurement standards or applying formulas that require a specific unit.

Worked examples

1 ton of refrigeration = 12,000 BTU per hour

1 BTU per hour = 0.29307107 watt

How to convert ton of refrigeration to BTU per hour

To convert ton of refrigeration to BTU per hour, multiply the value by 12,000.

To convert BTU per hour back to ton of refrigeration, multiply by 0.00008333.

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: ton of refrigeration to BTU per hour

ton of refrigerationBTU per hour
0.11,200
0.56,000
112,000
224,000
560,000
10120,000
25300,000
50600,000
1001,200,000
2503,000,000
5006,000,000
1,00012,000,000

Common values

ton of refrigerationBTU per hour
LED light bulb0.00284345 ton of refrigeration34.12141635 BTU per hour
Desktop computer0.08530354 ton of refrigeration1,023.64249054 BTU per hour
Microwave oven0.28434514 ton of refrigeration3,412.14163513 BTU per hour
Small car engine21.32588522 ton of refrigeration255,910.62263498 BTU per hour
Wind turbine (large)853.03540878 ton of refrigeration10,236,424.90539923 BTU per hour