A heat exchanger is a device that transfers thermal energy or heat from one fluid (primary side) to another fluid (secondary side) without direct contact or mixing of the two. The main function of a heat exchanger is to increase the energy efficiency of a heating or cooling system by transferring heat and thereby reducing energy costs.
The plate heat exchanger consists of several parallel plates closely placed which allows water to flow between them. The hot and cold water flow through alternating ‘chambers’ in the heat exchanger so that one side of a plate is always in contact hot water and the other with cold and thereby allowing the thermal transfer.
Heat exchangers are widely used in HVAC systems helping to cool or heat buildings, but they are also found in industrial application making machines and engines work more efficiently. And logically, size of a heat exchanger varies depending on the application and requirements.