Kilowatts to BTU per hour Converter

Exactly 1,000 watts make one kilowatt, written kW. This is the multiple that electrical equipment ratings use, and it equals one thousand joules of energy transferred per second.

Domestic appliance labels, generator sets, inverters, solar arrays and electric motors are all rated in kilowatts. Household demand and the capacity of a standby generator are usually quoted this way.

Since a kilowatt is a rate and a kilowatt-hour is an amount, multiplying kilowatts by hours of operation yields energy. Steps from watts to kilowatts to megawatts are exact powers of one thousand.

The common mistake is to add kilowatt ratings together and call the total energy use, when the total is only the power drawn at one moment. Consumption requires duration as well.

The kilowatt sits between the watt and the megawatt: appliance labels use watts, generators and inverters use kilowatts, and power stations use megawatts. An engine quoted in kilowatts cannot be compared directly with one quoted in horsepower without converting first.

One BTU per hour is exactly 0.29307107017222 watts, because one BTU is exactly 1,055.05585262 joules and an hour holds 3,600 seconds. The symbol is BTU/h.

Air conditioners, heat pumps, furnaces and chillers are rated in BTU per hour, and the figure on a room air conditioner describes its cooling capacity. Heating and cooling engineering uses the same unit for equipment sizing.

BTU per hour measures a rate, so it must be multiplied by a duration to produce an energy amount. Converting it to watts uses the exact factor, and 12,000 BTU per hour works out to about 3.5 kilowatts.

Treating BTU per hour as a unit of energy is a common error, since the same letters without the time element name an amount. A capacity rating and a consumption figure are therefore different quantities.

Cooling and heating capacities are quoted in BTU per hour, the electrical draw of the same equipment is quoted in kilowatts, and its motor may be quoted in horsepower. Choosing the wrong sibling changes the number by a factor of more than three.