Trane® / Mitsubishi Electric CITY MULTI®

VRF stands for Variable Refrigerant Flow, an HVAC technology that uses a single outdoor unit connected to multiple indoor units. It modulates the amount of refrigerant sent to each indoor unit, allowing precise temperature control, energy efficiency and zoning flexibility within the same system.

A heat pump VRF system can switch between heating and cooling, but all connected indoor units must operate in the same mode at any given time. This makes heat pumps ideal for open layouts or spaces with uniform comfort needs.

A heat recovery VRF system, on the other hand, uses a branch controller to manage refrigerant flow so that some zones can heat while others cool simultaneously. This is particularly valuable for buildings with mixed-use spaces or varying sun exposure. Heat recovery systems typically helps improve energy efficiency by transferring heat from zones requiring cooling to zones requiring heating.

A traditional VRF system circulates refrigerant directly to indoor units for both heating and cooling. All piping, including in occupied spaces, carries refrigerant.

 A hybrid VRF system uses refrigerant between the outdoor unit and a Hybrid Branch Controller but distributes water to indoor units instead of refrigerant. This design reduces refrigerant volume inside occupied spaces, helping with safety compliance (A2L refrigerants), lowers leak risk and simplifies maintenance.

VRF systems are best suited for buildings that need flexible, zone-level temperature control. With compact equipment, less ductwork and inverter-driven efficiency, VRF is ideal for projects prioritizing energy savings, electrification or space constraints.