Glossary – Definitions
Cooling production and heat recovery.

COP coefficient of performance ; coefficient of performance

Ratio of the useful effect of heat or cold on energy expenditure.

Quality factor ; second law efficiency

Ratio of actual COP to limit or ideal COP. This is efficiency in the sense of the second principle of thermodynamics.

Ejector machine ; ejector configuration machine

Includes at least one ejector.

Hybrid machine ; hybrid machine

Example: compression absorption machine.

Sorption machines ; sorption machine

Absorption or adsorption or resorption machine.

Thermoacoustic machine ; thermoacoustic machine

Uses sound waves.

Thermoelectric machines ; thermoelectric machine

Uses electrical phenomena.

Pulsed gas tubes ; pulse tube configuration machine

There are many variants: BPTR, IOPTR, DIPTR, HPTR.