EFCTC members developed and now produce HFOs, and designed HFO/HFC blends having a range of properties making them suitable for various applications. The first HFO Conference shows just how far the understanding and use of HFOs has progressed since they were first proposed about 15 years ago. Their good balance of safety and environmental properties and their technical performance has encouraged their use in a wide range of applications and also contributed to the introduction of the 2L ‘mildly flammable’ refrigerant classification. Their toxicity profiles are generally similar to the HFCs.
The HFOs and HFO/HFC blends are only a part of the solution to reducing the greenhouse gas emissions of HVAC systems. The recent TEAP report on energy efficiency (EE) while phasing down HFCs, points out that the largest potential for EE improvement comes from improvements in total system design and components, which can yield efficiency improvements (compared to a baseline design) that can range from 10% to 70% (for “best in class” unit). On the other hand, the impact of refrigerant choice on the EE of the units is usually relatively small – typically ranging from +/- 5 to 10%. The use of HFOs and HFO/HFC blends in well-designed best in class systems enables their safety properties to be utilised while at the same time reducing direct (refrigerant) and indirect (energy) GHG emissions. For some important applications, particularly where non-flammability is required or where mildly flammable 2L classification is appropriate, HFCs and lower GWP HFCs (HFC-32) continue to be used.
The HFO conference shared the learning developed for the use of mildly flammable refrigerants. The breadth and quality of the work presented was of a high standard, supporting the safe use of HFOs for RACHP applications. While HFOs may have been proposed about 15 years ago it is clear there will be scope for similar conferences in the future due to the extensive work being undertaken and the benefits of using HFOs.