About Units

Watt: The watt (W) is a unit of power in the International System of Units (SI), equivalent to one joule per second. It is named after James Watt, an 18th-century Scottish inventor. Watts are commonly used to measure the rate of energy transfer in electrical systems. For example, a typical incandescent light bulb consumes about 60 watts of power.

Tons of refrigeration: A ton of refrigeration (RT) is a unit of power used to describe the heat-extraction capacity of air conditioning and refrigeration equipment. One ton of refrigeration is equal to the rate of heat transfer needed to freeze 1 ton (2000 pounds) of water at 0°C in 24 hours, equivalent to 12,000 BTU per hour or approximately 3.517 kilowatts.