Air conditioner capacity is measured in tons. what is this ton means?

Answer 1

A rate of cooling that is equivalent to the removal of heat at 200 Btu/min (200 kilojoules/min), 12,000 Btu/h (13 megajoules/h), or 288,000 Btu/day (300 MJ/day). This unit of measure stems from the original use of ice for refrigeration. One pound of ice, in melting at 32°F (0°C), absorbs as latent heat approximately 144 Btu/lb (335 J/kg), and 1 ton (0.9 metric ton) of ice, in melting in 24 h, absorbs 288,000 Btu/day (300 MJ/day). In Europe, where the metric system is used, the equivalent cooling unit is the frigorie, which is a kilogram calorie, or 3.96 Btu. Thus 3000 frigories/h is approximately 1 ton of refrigeration. A standard ton of refrigeration is one developed at standard rating conditions of 5°F (−15°C) evaporator and 86°F (30°C) condenser temperatures, with 9°F (−13°C) liquid subcooling and 9°F (−13°C) suction superheat.

Domestic and commercial refrigerators may be rated in kJ/s, or Btu/h of cooling. Commercial refrigerators are mostly rated in tons of refrigeration. One ton of refrigeration capacity can freeze one short ton of water at 0 °C (32 °F) in 24 hours. Based on that:

Latent heat of ice (i.e., heat of fusion) ≈ 144 Btu / lb (or 334.5 kJ/kg)
One short ton = 2000 lb
Heat to be extracted = 2000 * 144 = 288000 Btu / 24 hours = 12000 Btu/hour = 200 Btu / Minute
1 ton refrigeration = 200 Btu / minute = 3.517 kJ/s = 3.517 kilowatts[8]
A much less common definition is: 1 tonne of refrigeration is the rate of heat removal required to freeze a metric ton (i.e., 1000 kg) of water at 0 °C in 24 hours. Based on the heat of fusion being 334.5 kJ/kg, 1 tonne of refrigeration = 13,938 kJ/h = 3.872 kW. As can be seen, 1 tonne of refrigeration is 10% larger than 1 ton of refrigeration.

Answer 2

Straight from the thermo book....

"The cooling capacity of a refrigeration system is often expressed in terms of TONS OF REFRIGERATION. The capacity of a refrigeration system that can freeze 1 ton (2000 lbm) of liquid water at 0C (32F) into ice at 0C in 24 hours is said to be 1 ton. One ton of refrigeration is equivalent to 211 KJ/min or 200 BTU/min. "

This is an old term. A ton means a normal ton - 2000 lbs. 200 BTU/min translates into 12,000 BTU/hr. Note in the definition that the water must be liquid and already at the freezing poing. It then freezes to the same temperature. This may sound confusing, but forget not your chemistry and latent heat of freezing.

Answer 3

A ton is 2240 lbs. But if you're talking about a metric ton (which is actually spelled 1 tonne) this is 1000 kg (kilograms).
But just so you know, a capacity is a volume, it's not measured by weight, it should be in gallons, pints, cups, cubic meters, cubic decimeters, cubic centimeters, etc.

Answer 4

One ton equals 12,000 BTUs/hour. It is derived from the amount of energy required to melt 1 ton of ice in a day.

Answer 5

What the 1st and 3rd guys, above, said -- I agree.

All I have to add, is that it took a 6 ton A/C unit to cool my 3-bedroom 1600 sq. ft. house in the summer, when I lived in Las Vegas, NV.


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