This could be a watershed year for variable refrigerant flow (VRF) systems in the United States. Although it has constituted only a small fraction of the overall heating, ventilation, and air conditioning (HVAC) market since its U.S. debut in 2003, the technology continues to gain traction. The VRF approach varies from traditional commercial chilled water or rooftop unit systems because it uses refrigerant to transfer heat in a building. The first advantage of this system is that the pipes are smaller. Because the refrigerant changes phase, less of it is needed to transfer a set amount of heat when compared to chilled water. VRF systems are also more efficient, since VRF compressors are inverter-driven and can operate at variable speeds. As a result, they are much more efficient in part-load conditions than the compressors in chillers or rooftop units.
Companies in the U.S. HVAC industry appear to be positioning themselves for a growing 2015 VRF market. Johnson Controls, for instance, announced in 2014 a joint venture with Hitachi to incorporate Hitachi’s VRF and inverter technology in Johnson Controls’ U.S. solutions portfolio. But the deal may not be completed until the first half of 2015. Also in 2014, Samsung Electronics America, Inc. agreed to acquire Quietside Corp., the North American distributor for Samsung’s HVAC products since 1997. The move marks Samsung’s focus on building the U.S. market for ductless and VRF products. Meanwhile, Trane further expanded its portfolio of VRF products through the addition of a water-source VRF system.
VRF systems are more efficient than conventional HVAC systems and have promising U.S. market potential for 2015. But they may ultimately not be the best means of increasing efficiency and comfort. Indeed, geothermal heat pumps (examined in detail in Navigant Research’s Geothermal Heat Pumps report) may be more efficient than VRF.
During the 2008 renovation of its headquarters, ASHRAE established the building as a living lab to evaluate new technologies. A portion of the project included installing a VRF system in part of the building and a geothermal heat pump in another part of the building. The results of a 2-year study of energy consumption indicate that the geothermal heat pump was more efficient than even the VRF system. Moreover, geothermal heat pumps are more similar to conventional systems than VRF systems are. They don’t entail the same changes in required installation skills, system design, and architecture.
Though a study of a single building in a single climate zone may not be rigorous enough to provide substantial conclusions, it certainly indicates that competing technologies, including both VRF and geothermal heat pumps, have a bright future.