Heat exchangers: What is it? Heat exchange must occur to allow HVAC to function. Convention, convection and conduction must all occur. HVAC is a function of these energy processes. This is illustrated by the sun. The main fluids utilized in HVAC systems are water and air. To work, an HVAC system requires air or water. The coil or the plate form will be utilized while setting up an HVAC system. Two tubes are available. Heat is transferred from the warm inner fluid to outer fluid. The plates made from metal, and are fixed in place. Convection then occurs through another fluid. The cooling or heating coil is very popular. The steam or water flow inside or outwards when warming the air. Transfer of heat is carried out by the sidewall. All pipes are connected. Heat exchanges in duct place make use of heat, without the requirement to use water. They are made of thin sheets of metal and typically, air is employed in both the processes. 1bdgistdev.