What is a heat exchanger?

• A. Any piece of equipment that transfers heat from one material to another
• B. A device that stores heat for later use
• C. A sensor that measures temperature
• D. A pump that circulates liquids

Answer: (A)

Heat exchangers are devices that move heat from one fluid to another without letting the fluids mix. The main idea is to transfer thermal energy across a boundary so one stream can be heated or cooled while the other remains separate. This transfer happens across a solid barrier or a network of tubes/plates that provides a large surface area for heat to flow efficiently. They’re used in many systems, like car radiators or air conditioners, to control temperatures without mixing the substances. The other options describe storing heat, measuring temperature, or pumping fluids, none of which define what a heat exchanger does.