Kilowatt (kW)
The kilowatt (kW) is 1,000 watts. As electricity became essential in the late 19th and 20th centuries, the kilowatt became the common unit for household appliances, motors, and power generation. Household energy use is measured in kilowatt-hours (kWh), which track energy consumption over time. Kilowatts are also used for engines, renewable energy, and national grids. By scaling up from the watt, the kilowatt lets us express real-world power needs and production more easily. As we consider other systems for measuring power, it is useful to explore both non-metric and higher-magnitude units such as horsepower and the megawatt.
BTU per hour (BTU/hr)
BTU per hour (BTU/hr) is a power measurement derived from the British Thermal Unit, which represents the heat needed to raise one pound of water by one degree Fahrenheit. One BTU/hr corresponds to about 0.293 watts. This unit has traditionally been used in both the UK and US, especially within the heating, ventilation, and air conditioning (HVAC) sector. It is still widely employed to rate the output of appliances like furnaces and air conditioners. Despite not being part of the metric system, BTU/hr persists in North America due to its deep-rooted presence in industry standards and consumer usage.