A HVAC interior unit is a type of air conditioning system that is installed inside a building or structure. It is responsible for providing a comfortable indoor environment by controlling the temperature, humidity, and air quality of the interior space. The HVAC interior unit is composed of several components, including a compressor, condenser, evaporator, and expansion valve. The compressor pumps refrigerant through the system, which is then cooled and circulated through the interior space. The condenser removes heat from the refrigerant, while the evaporator absorbs heat from the interior air and transfers it to the refrigerant. The expansion valve regulates the flow of refrigerant and the temperature of the interior air. The HVAC interior unit is designed to provide a comfortable and healthy environment, while also helping to reduce energy costs.