This four-part series by Eamonn Ryan explores how Variable Refrigerant Flow (VRF) systems are transforming HVAC design amid the global shift to low-GWP refrigerants and stricter energy standards. Drawing insights from ASHRAE experts featured in the ASHRAE Journal Podcast #52: ‘VRF Systems in an A2L World’, the series examines how innovation, safety standards, and international collaboration are shaping the future of climate control in commercial and residential buildings. The following article is part one.
As building owners, consultants and contractors increasingly face pressure to reduce energy consumption and carbon footprint, Variable Refrigerant Flow (VRF) systems are emerging as a key solution in modern HVAC design. A recent discussion on the ASHRAE Journal Podcast number 52, ‘VRF Systems in an A2L World’, highlighted how the technology is evolving in response to new refrigerant regulations, design standards and global trends – while offering unique operational benefits that set it apart from traditional HVAC systems.
VRF, a system that allows for precise temperature control across multiple zones using a single refrigerant circuit, has long been praised for its flexibility. Scott McGinnis, P.E., a veteran engineer and ASHRAE committee participant involved in the development and application of VRF, emphasised that one of its standout features is the ability to perform simultaneous cooling and heating. This heat recovery capability allows energy to be transferred from spaces that need cooling to those that require heating, improving efficiency and reducing operating costs. While different manufacturers have branded the core component that enables this functionality – the heat recovery control unit – under various trade names, ASHRAE has worked to establish a standard terminology. In the VRF guideline SGPC 41 and the ASHRAE Handbook, the unit is consistently referred to as the ‘heat recovery control unit’, providing a baseline for designers, engineers and contractors navigating the technology.