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.

Btu per hour: BTU per hour (BTU/h) is a unit of power that describes the power of heating and cooling systems, such as furnaces, ovens, and air conditioners. One BTU per hour is the rate at which one British Thermal Unit of energy is transferred in one hour. For example, the cooling capacity of a residential air conditioner might be rated at 10,000 BTU per hour.