Evaluation of Odorizing Refrigerant R-290 to Improve Leak Detection-System Performance and Compatibility
R-290 (propane) is a flammable refrigerant having an A3 classification according to the ASHRAE Standard 34. Because of its extremely low Global Warming Potential (GWP), several regions around the world use or consider using it for air-conditioning and refrigeration applications. On the other hand, its high flammability and safety implications limited its broader application. Odorizing R-290 would make its leak easier to detect by humans. The ability to smell a leak would not only benefit the consumer but would also prompt timely repair and create a safer working environment for the HVACR manufacturer and field service personnel. However, applying the odorant in R-290 systems with unknown compatibility with the compressor lubricant and construction materials may result in premature chemical or electrical failure and the degradation of the system efficiency. The Air-Conditioning, Heating, and Refrigeration Technology Institute (AHRTI) undertook a research project to conduct experimental testing to evaluate odorants impact on system performance and odorants compatibility with refrigerant R-290, lubricants and other materials commonly used in HVACR equipment. This paper provides an overview of the testing effort and summarizes the test results of R-290 and odorant in a mini-split heat pump and a commercial refrigerated display case (reach-in cooler). A brief summary of compatibility testing results of R-290 with two odorants, three lubricants and other system materials will be presented as well.