Heating, ventilation, and air conditioner are an art of vehicular and indoor environmental control. Its primary function is to provide acceptable indoor air quality and thermal comfort for the occupants. In its simplest form, HVAC involves the mechanical extraction of heat or cool air from a source, which may be an external temperature or pressure change or fluctuation in relative humidity. The process causes the transfer of energy within the material and changes the temperature of the air.
There are four types of HVAC namely, hydronic, oil, gas, and electric. An HVAC system can be either a passive or an active heating and cooling system. An HVAC system is also known as a forced-air furnaces, furnace room, or a crawl space. In addition to heating and cooling systems, HVAC can also provide insulation, cooling, ventilating, air-conditioning, and heating.
For a HVAC system to function efficiently, it must have proper mechanical ventilation. Mechanical ventilation (MV) occurs when the mechanical pumps, fans, compressors, evaporators, and motors that are part of the HVAC system transfer air into a conditioned space and prevent the entry of outside air. In an effort to prevent the escape of heated or cooled air, HVAC systems can work on principles such as surface tension, buoyancy, flow control, and cross-flow. A HVAC system can be part of a complete heating and cooling system, or it can be part of an energy-efficient decorating system. The HVAC industry refers to HVAC as ductwork, ductless, or forced-air furnaces.