The answer to 'difference between heat exchanger and' is that a heat exchanger and a furnace are two distinct components in a home's HVAC (Heating, Ventilation, and Air Conditioning) system. A heat exchanger is a device that transfers heat from one medium to another, while a furnace is the appliance that generates the heat.
A heat exchanger is typically found inside the furnace or air handler unit. Its primary function is to transfer the heat generated by the furnace to the air that is circulated throughout the home. This allows the HVAC system to efficiently distribute the warm air without the hot combustion gases from the furnace entering the living space. In contrast, a furnace is the appliance that burns fuel, such as natural gas, propane, or oil, to generate the heat that is then transferred to the air by the heat exchanger.