Conference Year
2016
Keywords
low GWP, RTU, DR-55, IEER, modeling
Abstract
R410A has zero ozone depletion potential (ODP), and is the most commonly used refrigerant in vapor compression systems for space cooling and space heating applications. However, it has significant global warming potential with GWP higher than 2000. To mitigate the global warming effect, industry and research institutes are actively pursuing a replacement for R410A, which should have much lower GWP, similar or higher efficiency.  DR-55 is a design-compatible refrigerant replacement for R410A, which can be used as a direct drop-in replacement. It decreases the GWP by 70%, and has lower working pressure, comparable discharge temperature, same lubricant, tubing, valves. In this study, we investigated using DR-55 to replace R410A in a high efficiency rooftop air conditioning unit by laboratory testing. The lab results demonstrated that DR-55 led to 5% higher efficiency at the working conditions of Integrated Energy Efficiency Rating (IEER). DR-55 also showed significantly better high ambient performance from 95°F to 125°F. In addition to the experimental study, we conducted extensive equipment modeling study to assess cooling and heating performances of DR-55 in single-speed and variable-speed units, in comparison to R-410A.Â