What is the definition of a VRF residential system? VRF, or Variable Refrigerant Flow, is a highly efficient air conditioning system that is commonly used in commercial and industrial buildings. It works by using a single outdoor unit to regulate the temperature of several indoor units. This system is an excellent choice for residential homes because of its energy efficiency, which can help reduce energy costs significantly. The system is made up of an outdoor condensing unit, which is connected to several indoor units that are located in the living areas of a home. These indoor units are connected to a control panel, which allows the homeowner to set the temperature for each room as needed. The outdoor unit then distributes refrigerant through a network of piping to the indoor units, allowing them to heat or cool the air accordingly. VRF systems are known for their efficiency and effectiveness, and can provide a comfortable environment for a home.