Understanding Tons of Refrigeration to British thermal units per hour Conversion
A ton of refrigeration (RT) is a unit of cooling power equal to the rate of heat removal needed to freeze one short ton of water in 24 hours, defined as exactly 12,000 British thermal units per hour. The British thermal unit per hour (Btu/h) is the customary unit of heat-flow rate used in HVAC ratings. This conversion is fundamental in air-conditioning and chiller specifications.
Conversion Formula
To convert Tons of Refrigeration to British thermal units per hour, multiply the number of Tons of Refrigeration by this factor:
Step-by-Step Example
Convert 25 Tons of Refrigeration to British thermal units per hour.
Write the formula:
Substitute the value:
Calculate the result:
How to Convert Tons of Refrigeration to British thermal units per hour
Use the fixed conversion factor to turn any Tons of Refrigeration value into British thermal units per hour.
- Find the factor: One RT equals 12000 Btu/h.
- Set up the formula: Write Btu/h = RT \times 12000.
- Multiply your value: Take your number of Tons of Refrigeration and multiply it by 12000.
- Read the result: For example, 25 RT gives about 300000 Btu/h.
Tons of Refrigeration to British thermal units per hour conversion table
| Tons of Refrigeration (RT) | British thermal units per hour (Btu/h) |
|---|---|
| 0 | 0 |
| 1 | 12000 |
| 2 | 24000 |
| 3 | 36000 |
| 4 | 48000 |
| 5 | 60000 |
| 6 | 72000 |
| 7 | 84000 |
| 8 | 96000 |
| 9 | 108000 |
| 10 | 120000 |
| 15 | 180000 |
| 20 | 240000 |
| 25 | 300000 |
| 30 | 360000 |
| 40 | 480000 |
| 50 | 600000 |
| 60 | 720000 |
| 70 | 840000 |
| 80 | 960000 |
| 90 | 1080000 |
| 100 | 1200000 |
| 150 | 1800000 |
| 200 | 2400000 |
| 250 | 3000000 |
| 300 | 3600000 |
| 400 | 4800000 |
| 500 | 6000000 |
| 600 | 7200000 |
| 700 | 8400000 |
| 800 | 9600000 |
| 900 | 10800000 |
| 1000 | 12000000 |
| 2000 | 24000000 |
| 3000 | 36000000 |
| 4000 | 48000000 |
| 5000 | 60000000 |
| 10000 | 120000000 |
| 25000 | 300000000 |
| 50000 | 600000000 |
| 100000 | 1200000000 |
| 250000 | 3000000000 |
| 500000 | 6000000000 |
| 1000000 | 12000000000 |
What is the Ton of Refrigeration?
The ton of refrigeration (RT) is a unit of power that measures the rate of heat removal in cooling and air-conditioning systems. It is widely used in the HVAC industry to rate chillers, air conditioners, and industrial refrigeration equipment.
Definition
One ton of refrigeration is the rate of heat transfer needed to freeze 2,000 pounds (one short ton) of water at 0 °C into ice at 0 °C over 24 hours. Using the latent heat of fusion of water, this equals exactly 12,000 Btu/h, which is:
Equivalently, . It is a power (heat-flow) unit, not a unit of mass or energy; the NIST Guide to the SI (SP 811) lists the ton of refrigeration (12 000 Btu(IT)/h) as 3.516 853 × 10³ W.
Origin and History
The unit dates to the 19th century, when mechanical refrigeration competed directly with the natural-ice trade. Cooling capacity was rated by how much ice a machine could effectively replace, so one "ton" of refrigeration described equipment capable of melting one ton of ice per day. The measure stuck even as ice harvesting disappeared.
Law and Notable Facts
The ton of refrigeration is not an SI unit; the SI unit of power is the watt. It remains an industry standard in North America, where residential air conditioners are commonly sized in tons (for example, a "3-ton" central AC unit). Note that the "ton" here refers to heat-removal rate, not the weight of the equipment. A closely related metric variant, the frigorie-based commercial ton, is defined slightly differently in some regions, but the U.S. value of exactly 12,000 Btu/h is the most common.
Real-World Examples and Conversions
- A typical residential central air conditioner rated at 3 RT removes about 36,000 Btu/h, or roughly 10,551 W of heat.
- A single ton of refrigeration (3516.85 W) is comparable to the cooling output of a large window AC unit sized for a big room.
- Large commercial chillers are often rated in the hundreds or thousands of tons; a 500 RT chiller handles about 1.758 MW of heat load.
- To convert tons to kilowatts of cooling, multiply by 3.51685: a 2 RT mini-split delivers about 7.03 kW of cooling.
What is the British thermal unit per hour?
The British thermal unit per hour (Btu/h) is a unit of power, or heat-flow rate, that expresses how much thermal energy is moved each hour. It is the standard rating unit for heating, ventilation, and air-conditioning (HVAC) equipment in the United States.
Definition
One Btu/h is one British thermal unit of energy transferred over one hour. Because 1 Btu is a fixed quantity of energy and 1 hour is 3,600 seconds, the rate converts exactly to the SI unit of power, the watt:
Equivalently, 1 W = 3.41214 Btu/h. Btu/h is a power (heat-flow) unit, not an energy unit; the related "ton of refrigeration" equals 12,000 Btu/h. The value above uses the International Table Btu (1 Btu = 1,055.06 J), and the NIST Guide to the SI (SP 811) tabulates 1 Btu(IT)/h = 2.930 711 × 10⁻¹ W.
Origin and History
The British thermal unit dates to 19th-century engineering, defined as the heat needed to raise one pound of water by one degree Fahrenheit. As steam and later mechanical cooling systems spread, engineers needed a rate of heat transfer rather than a bulk energy figure, so the Btu was paired with the hour to describe furnace output and cooling capacity. The unit persisted in the English-speaking world even as the watt became the SI standard.
Law and Notable Facts
Btu/h is not part of the SI, but it remains legal and dominant in US and UK trade for rating boilers, furnaces, and air conditioners. Air-conditioner "tons" are a direct Btu/h measure: a 1-ton AC removes 12,000 Btu/h of heat, based on the energy needed to melt one short ton of ice in 24 hours. Because it is a rate, Btu/h answers "how fast," while plain Btu answers "how much."
Real-World Examples and Conversions
- A window air conditioner rated at 10,000 Btu/h delivers about 2,930 W (2.93 kW) of cooling.
- A residential gas furnace of 80,000 Btu/h supplies roughly 23,400 W (23.4 kW) of heat.
- A 3-ton central AC system is rated at 36,000 Btu/h, equal to about 10,550 W.
- A small 1,500 W electric space heater produces about 5,118 Btu/h.
Frequently Asked Questions
What is the formula to convert Tons of Refrigeration to British thermal units per hour?
Multiply the number of Tons of Refrigeration by 12000. In symbols, Btu/h = RT \times 12000.
How many British thermal units per hour are in 1 Ton of Refrigeration?
One Ton of Refrigeration equals 12000 Btu/h. A ton of refrigeration is defined as exactly 12,000 Btu/h by convention.
How do I convert 10 Tons of Refrigeration to British thermal units per hour?
Multiply 10 by 12000, which gives about 120000 Btu/h.
What does a ton of refrigeration measure?
A ton of refrigeration is defined as exactly 12,000 Btu/h by convention.
Where is the Tons of Refrigeration-to-British thermal units per hour conversion used?
It is central to HVAC sizing, where cooling equipment rated in tons is compared against loads expressed in Btu/h.
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Complete Tons of Refrigeration conversion table
| Unit | Result |
|---|---|
| Watts (W) | 3516.853 W |
| Milliwatts (mW) | 3516853 mW |
| Kilowatts (kW) | 3.516853 kW |
| Megawatts (MW) | 0.003516853 MW |
| Gigawatts (GW) | 0.000003516853 GW |
| Horsepower (metric) (PS) | 4.781589 PS |
| British thermal units per hour (Btu/h) | 12000 Btu/h |
| British thermal units per second (Btu/s) | 3.333333 Btu/s |
| Foot-pounds per second (ft-lb/s) | 2593.898 ft-lb/s |
| Horsepower (British) (hp) | 4.716177 hp |