In boiler systems, the economizer is classified as what?

• A. A heat recovery component
• B. A safety device
• C. A feedwater heater
• D. A condensate pump

Answer: (C)

An economizer is a heat exchanger that taps heat from the boiler’s exhaust gases to raise the temperature of the feedwater returning to the boiler. This preheating reduces the energy required to convert water into steam, improving overall boiler efficiency. Because its primary function is heating the feedwater before it enters the boiler, it is classified as a feedwater heater. While it does recover heat from waste flue gas and is thus a form of heat recovery, the defining classification in this context is that it heats the feedwater. It is not a safety device and not a condensate pump, which have different roles in the system.