It is likely 2019 will be referred to as the year when Variable Refrigerant Flow (VRF) systems finally earned a patient hearing in the United States. In March 2019, ASHRAE Guideline 41 on design, installation and commissioning of VRF systems came up for Public Review, perhaps representing a significant shift in thinking in the United States. (The Guideline is expected to be released in early 2020.)

For long considered an enigma – perhaps even an oddity – VRF systems, which emerged in Japan in the early 1980s – are at long last being viewed as a commercial cooling option for projects across the country, where traditional ducted systems remain the system of choice for heating and cooling in the builtenvironment. Suddenly, the prospect of zone-based cooling and greater energy efficiency among comparable systems, is finding appeal among consultants, contractors and developers. Still, the absence of substantial field performance data is a barrier for acceptance, as are some other factors.

The World VRF Congress is a non-parochial, third-party platform that seeks to provide an in-depth understanding of VRF technology and an insight into its energy consumption and other aspects through relevant case studies from the United States and the rest of the world. Produced by CPI America, a sister company of CPI Industry, publishers of Climate Control Journal and Climate Control ME, the Congress is part of a broader mission by the publishing house to present various cooling approaches that lower indirect greenhouse gas emissions, reduce the total cost of ownership and offer reliable comfort cooling across multiple end-user sectors.

At a Glance

  • As per market analysts, the global VRF market was worth over USD 11 billion in 2015, and this figure is predicted to reach more than USD 24 billion in just five years (by 2022). That equates to an 11.4% compound annual growth rate.
  • As per market analysts, VRF is the most popular HVAC technology in many overseas markets, making up 90% of installed commercial systems in Japan, 86% in China, and 81% in Europe.
  • VRF systems are believed to be well-suited for health care facilities, classrooms, hotels and office buildings.
  • According to a research study conducted at the Oak Ridge National Laboratory in TN, USA and supported by the National Research Foundation of Korea (NRF), VRF systems had an average COP of 4.2, 3.9, and 3.7 compared with 3.1, 3.0, and 2.5 for RTU systems under 100%, 75%, and 50% load conditions and resulted in estimated energy savings of 30%, 37%, and 47%, respectively, during the cooling season. VRF systems had an average COP ranging from 1.2 to 2.0, substantially higher than the COPs of the RTU system, and resulted in estimated energy savings of 51%, 47%, and 27% under the three load conditions, respectively, during the heating season.
  • According to another research undertaken in 2017 at the Oak Ridge National Laboratory in TN, USA, the objective of which was to evaluate the energy savings potential of VRF systems vis-à-vis rooftop unit (RTU) variable air volume (VAV) systems across 16 climate zones in the United States, VRF systems would save around 15-42% and 18-33% for HVAC site and source energy uses compared to the RTU-VAV systems.
  • According to the Oak Ridge study, when compared to the RTU-VAV models as a percentage of total HVAC fan energy use, a simulation analysis shows that the VRF HP models use around 26-50% less HVAC fan site energy than the RTU-VAV models throughout the chosen climate locations.
  • According to the Oak Ridge study, comparing annual HVAC cost savings as a percentage savings, the VRF Heat Pump models mostly showed higher cost savings potential than the RTU-VAV models within hot and mild climates, while the RTU-VAV models used less HVAC energy costs in several cold climate zones, mainly due to the differences in electricity and gas consumption.