The answer to 'how does heat exchanger work' is that a heat exchanger is a device used in HVAC systems to transfer heat from one fluid (either air or liquid) to another. It consists of a series of metal coils or plates that allow heat to be exchanged between the two fluids without them coming into direct contact. As the warm air or liquid passes through the heat exchanger, it transfers its heat to the cooler air or liquid on the other side, allowing the system to heat or cool the air as needed.
Heat exchangers are a critical component of HVAC systems, as they enable the efficient transfer of thermal energy and help maintain the desired temperature and air quality in a home or building. They are found in furnaces, air conditioners, heat pumps, and other HVAC equipment.