economizer
Definitions
A device used to reduce fuel consumption or to perform other useful functions, such as preheating a fluid.
A person or entity that practices economy or avoids waste.
Examples
The industrial boiler was fitted with an economizer to recover waste heat from the flue gases.
By acting as a smart economizer, the new HVAC system significantly reduced the building's monthly energy consumption.
Synonyms
saver thrifty person frugal individual penny pincher budgeter