HVAC stands for heating, ventilation, and air conditioning. There are many different types of HVAC systems that rely on different types of technology to function, but their core purpose is to provide heating and cooling. Here are two of the most common types of residential HVAC systems and how they work: Standard split: Split HVAC systems consist of two main components – one for heating and one for cooling. The cooling component is typically installed on the outside of the home and uses a refrigerant to cool the air before carrying it indoors. Meanwhile, the heating component is installed indoors and is controlled using a thermostat.  Ductless or mini-split: Mini-splits are becoming increasingly popular because they are compact and don’t need extensive ductwork. In these systems, both the heating and cooling components are kept together in one unit rather than split between different areas of the home. Most also use a heat pump to transfer thermal energy between spaces, which can significantly reduce energy consumption.