How many kW is one ton of refrigeration?

One ton of refrigeration is about 3.517 kilowatts of cooling, which equals 12,000 BTU per hour. This is thermal cooling, not the electricity the chiller consumes.

kW per TR is the electrical power used for each ton of cooling delivered. It is a common efficiency measure for chillers and refrigeration plants, where lower is better.

Is installed TR the same as delivered TR?

No. Installed TR is rated capacity. Delivered TR is the cooling actually produced at a given time, calculated from flow and temperature difference.

Why is it called a ton?

The unit comes from the heat needed to melt one short ton of ice over a day, from when buildings and food were cooled with ice.

Glossary

Dairy and food processing

What is Ton of refrigeration (TR)?

Definition

A ton of refrigeration (TR) is a unit of cooling capacity equal to 12,000 BTU per hour, or about 3.517 kilowatts of heat removed. It comes from the heat needed to melt one short ton of ice in a day, and it is used to size chillers, refrigeration plants and air conditioning.

What it is

A ton of refrigeration measures the rate of heat removal, not weight. One TR is 12,000 BTU per hour, which is about 3.517 kilowatts of thermal cooling. The unit dates from the era of ice-based cooling, when capacity was described as the ice melted per day.

Chillers, ammonia plants and air conditioning systems are rated in TR, and installed capacity is often given as a plant total. Actual cooling delivered at any moment is usually lower than rated capacity and varies with load and weather.

TR is often paired with electrical input to describe efficiency as kW per TR. A lower kW per TR means less electricity for the same cooling.

Who it applies to / where it is used

TR is the standard capacity unit in India, the Middle East and North America for chillers and refrigeration plants in dairies, food plants, airports, hospitals, data centers and commercial buildings. Europe more often uses kilowatts of cooling.

How it is measured / what evidence it needs

Delivered TR is calculated from chilled water or glycol flow and the temperature difference across the evaporator. That needs a flow meter and accurate supply and return temperatures.

Chilled water or brine flow rate
Supply and return temperature difference
Delivered cooling in TR over time
Compressor, pump and fan electrical input
kW per TR at comparable load and weather

How Aqueduct helps

Aqueduct turns flow, temperature and power into delivered TR and kW per TR, live for each plant.

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