HVAC stands for Heating, Ventilation, and Air Conditioning. It is a term used to describe the different systems used for moving air between indoor and outdoor areas, along with heating and cooling both residential and commercial buildings. The goal of an HVAC system is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer.

An HVAC system is made up of multiple units and parts, both inside and outside your home, that all work together doing different jobs to bring you the complete home comfort you need. The components of an HVAC system include a heating unit, a cooling unit, and ducts to move the air. The different parts of an HVAC system work to not only warm you in winter and cool you in summer but also filter and purify your air to help protect you and your family from allergens, pollutants, and harmful chemicals.

The purpose of an HVAC system is more than just warming or cooling a space. Instead, it serves to improve indoor air quality and provide comfort for everyone inside a building. HVAC systems can be used in both domestic and commercial environments, including residential structures such as single-family homes, apartment buildings, hotels, and senior living facilities; medium to large industrial and office buildings such as skyscrapers and hospitals; vehicles such as cars, trains, airplanes, ships, and submarines; and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fresh air from outdoors.