. From what I can tell … HVAC may also represent high voltage alternating current HVAC (pronounced "HVAC" or, occasionally, "H-VAK" is an abbreviation / acronym that stands for "heating, ventilating and air conditioning . "This is sometimes referred to as climate control. These three functions are closely interrelated, since the control of temperature and humidity in a building along with providing for smoke control, maintain pressure relationships between spaces and provide fresh air for the occupants. In modern building designs, systems design, installation and control of these functions are integrated into a single "HVAC system." In some regions (e. G., UK ), also the term "Building Services" is used and HVAC engineers are called Building Services Engineers. See CIBSE.'s air handler term can mean a complete unit that includes the elements of fan, heating and cooling, racks or filter chamber and shock absorbers, but not including the conduit through the building.