Benefits and challenges in deployment of low global warming potential R290 refrigerant for room air conditioning equipment in California
Max Wei, Chao Ding, Greg Rosenquist, Katie Coughlin, Ed Cubero, Tom Burke, Omar Abdelaziz
Abstract
• Life-cycle cost modeling performed for three room AC types with R290 refrigerant. • Room air conditioners with R290 refrigerant have small increases in equipment cost. • Estimated 15 to 64 million metric tons of greenhouse gas (GHG) savings in California. • Cost per ton of CO 2 eq saved for R290 transition in room AC ranges from $14 to −$50. High global warming potential gases (“high GWP”) are the fastest growing sector of greenhouse gas emissions in the world and in California and are primarily used as refrigerant gases in refrigeration and cooling equipment. Hydrofluorocarbons (HFCs) refrigerants are the dominant type of high GWP gases with GWP values thousands of times larger than CO 2 on a 100-year timescale. Refrigerant-grade propane (“R290”) has a very low GWP (GWP = 3.3) with good thermodynamic properties and good cooling equipment performance but the flammability of any leaked refrigerant makes equipment design, handling, and maintenance critical factors to manage. This paper focuses on the potential climate benefits and costs of transitioning to R290 refrigerant in small room air conditioning (AC) units, specifically window AC, packaged terminal AC/heat pumps (PTAC/PTHP), and mini-split heat pumps. Overall climate impact for a transition to all three types of air conditioning units in the 2022–2051 timeframe is found to be from 15 to 64 million metric tons of greenhouse gas (GHG) savings in California with a cost of saved CO 2 eq that ranges from $14.50 per ton of CO 2 eq saved to −$50.30 per ton of CO 2 eq saved (net savings) depending on whether the baseline refrigerant is R32 or R410A and depending on the relative energy efficiency for R290 units compared to baseline units.