HVAC stands for Heating, Ventilation, and Air Conditioning. It refers to the technology, systems, and equipment used to regulate the indoor environment, including temperature, humidity, and air quality.

The basic components of an HVAC system include heating equipment, ventilation equipment, air conditioning equipment, thermostats, air filters, and humidifiers/dehumidifiers. These components work together to maintain a comfortable and healthy indoor environment.

Heating equipment uses energy, such as gas or electricity, to generate heat and warm indoor air. Ventilation equipment circulates and distributes air throughout the building. Air conditioning equipment uses a refrigerant to control indoor temperature and humidity through the process of evaporation and condensation.

Thermostats monitor indoor temperature and control the heating and cooling systems to maintain a desired temperature. Air filters remove dust, pollen, and other pollutants from indoor air. Humidifiers and dehumidifiers add or remove moisture from indoor air to maintain a comfortable level of humidity.

By coordinating the function of these components, an HVAC system can maintain a stable and comfortable indoor environment in different seasons and weather conditions.