HFCs are factory-made chemicals primarily used in air conditioning, refrigeration, and foam insulation, and they can be up to 10,000 times more potent than carbon dioxide in contributing to climate change. Absent ambitious action to limit their use, emissions of HFCs are expected to nearly triple in the U.S. by 2030. But, with strong international action to phase down HFCs, we can avoid up to 0.5°C of warming by 2100, substantially furthering our goal to limit goal temperature rise.

Phasing down HFCs presents not only a huge climate opportunity, but also one of the biggest opportunities to cut energy costs for consumers. HVAC, water heating, and refrigeration systems are the largest energy end-use in buildings, using nearly 50% of all energy in U.S. commercial and residential buildings. With such a large impact on the buildings sector, DOE’s Quadrennial Technology Review identified technological efficiency improvements in HVAC systems—which go hand-in-hand with reducing HFC emissions—as one of the nation’s most promising research opportunities.

• April 2016: Trane Commercial Systems and Oak Ridge National Laboratory improve a baseline commercial rooftop air-conditioning unit's mechanical design and substitute R-410 for a lower-GWP refrigerant (DR-55), demonstrating a 25% improvement in efficiency and 67% lower GWP.
• February 2016: As part of the Energy Materials Network, DOE launches a new research consortium at Ames Laboratory to discover and develop caloric materials that could lead to advanced, low-GWP refrigeration technology. BTO serves as a technical advisor.
• November – December 2015: DOE convenes two workshops to solicit input from over 100 industry stakeholders — including manufacturers, national laboratories, and universities — on the technical focus and overall structure needed for a successful next-generation HVAC&R research effort.
• November 2015: All 197 parties to the Montreal Protocol on Substances that Deplete the Ozone Layer agree on a "Dubai Pathway" — to work together, within the Montreal Protocol, to an HFC amendment in 2016 by first resolving challenges and generating solutions in the contact group on the feasibility and ways of managing HFCs at Montreal Protocol meetings.
• October 2015: Oak Ridge National Laboratory’s performance evaluation of alternative lower global warming potential refrigerants shows that they could be used to successfully replace hydrochlorofluorocarbon and hydrofluorocarbon (HFC) refrigerants in hot climates. The results are of particular interest to many developing countries that have hot climates, and support the proposed amendment to the Montreal Protocol to phase down the use of HFC refrigerants.
• September 2015: Xergy develops the first electrochemical compressor for home water heaters, and ships it to their industry partner for development of a complete prototype. Xergy’s technology is one of the first in a new class of super-efficient, low-GWP technologies called "non-vapor compression" — which are transforming how heating and cooling technologies have operated for the past 100 years.
• April 2015: DOE invests nearly $8 million to develop advanced vapor compression and non-vapor compression HVAC systems.
• January 2015: Honeywell, working with ORNL, commercializes Solstice N40, a low-global warming potential non-HFC refrigerant that provides a 67% reduction in GWP and up to 10% increased energy efficiency for supermarket refrigeration.
• November 2014: Leading refrigeration systems manufacturer Hillphoenix, working with ORNL, commercializes a CO₂-based supermarket refrigeration system that does not use HFCs, reduces greenhouse gas emissions by 75%, and lowers energy consumption by 25% compared to existing systems. The system has been installed in over 130 stores across the U.S.

Short-Term Strategy: Develop, evaluate, and deploy low-GWP alternative refrigerants and systems.

• Thermodynamic Evaluation of Low-Global-Warming-Potential Refrigerants – National Institute of Standards and Technology – Gaithersburg, MD
• Low-GWP Refrigerants for Refrigeration Systems – Oak Ridge National Laboratory – Oak Ridge, TN
• Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments – Oak Ridge National Laboratory – Oak Ridge, TN
• High-Efficiency, Low-Emission Refrigeration System – Oak Ridge National Laboratory – Oak Ridge, TN
• Next-Generation Rooftop Unit – Oak Ridge National Laboratory – Oak Ridge, TN
• Commercial Deployment of Alternative Refrigerants – BTO High Impact Technology Catalyst Program

Mid-Term Strategy: Develop advanced HVAC&R systems that can handle low-GWP refrigerants.

• High-Efficiency Low Global-Warming Potential (GWP) Compressor – United Technologies Research Center – East Hartford, CT
• Low-Global Warming Potential HVAC System with Ultra-Small Centrifugal Compression – Mechanical Solutions, Inc. – Whippany, NJ
• Natural Refrigerant High-Performance Heat Pump for Commercial Applications – S-RAM – Franklin, TN
• Miniaturized Air-to-Refrigerant Heat Exchangers – University of Maryland, College Park, MD
• CBERD: Advanced HVAC Systems – Oak Ridge National Laboratory – Oak Ridge, TN (Joint U.S.-India project)
• Residential CO₂ Heat Pump Water Heater – Oak Ridge National Laboratory – Oak Ridge, TN
• Commercial CO₂ Heat Pump Water Heater – Oak Ridge National Laboratory – Oak Ridge, TN
• Max Tech Electric Heat Pump Water Heater with Lower GWP Halogenated Refrigerant – Oak Ridge National Laboratory – Oak Ridge, TN

Long-Term Strategy: Develop non-vapor compression systems that use zero-GWP refrigerants.

• Natural Gas Heat Pump and Air Conditioner – Thermolift – Stony Brook, NY
• Residential Adsorption Heat Pump Water Heater – Oak Ridge National Laboratory – Oak Ridge, TN
• Commercial Absorption Heat Pump Water Heater – Oak Ridge National Laboratory – Oak Ridge, TN
• Residential Absorption Heat Pump Water Heater – Oak Ridge National Laboratory – Oak Ridge, TN
• Magnetocaloric Refrigerator/Freezer – Oak Ridge National Laboratory – Oak Ridge, TN
• Novel Solid State Magnetocaloric Air Conditioner – Oak Ridge National Laboratory – Oak Ridge, TN
• High Efficiency Solid-State Heat Pump Module – United Technologies Research Center – East Hartford, CT
• Heat Pump Water Heater Using Solid-State Energy Converters – Sheetak – Austin, TX
• Advanced Hybrid Water Heater Using Electrochemical Compressor – Xergy – Seaford, DE
• Low-Cost Electrochemical Compressor Utilizing Green Refrigerants for HVAC Applications – Xergy – Seaford, DE
• Compact Thermoelastic Cooling System – Maryland Energy and Sensor Technologies, LLC – College Park, MD
• Membrane Based Air Conditioning – Dais Analytic Corporation – Odessa, FL