In thermodynamics, the thermal efficiency () is a dimensionless performance measure of a device that uses
For a … See more

Heat engines transform thermal energy, or heat, Qin into mechanical energy, or work, Wout. They cannot do this task perfectly, so some of the input heat energy is not converted into work, but is dissipated as waste heat… See more

For a device that converts energy from another form into thermal energy (such as an electric heater, boiler, or furnace), the thermal efficiency is
where the quantities are heat-equivalent values. … See more

Heat pumps, refrigerators and air conditioners use work to move heat from a colder to a warmer place, so their function is the opposite of a heat engine. The work energy (Win) that is applied to them is converted i… See more