“…In a different paper, Erickson et al (1996b) have presented experimental analysis on a branched GAX cycle gas fired heat pump. Afterward, similar works have been carried out by Phillips (1999) and Prideman et al (2001) on different experimental machines. The three works have shown cooling cycle COP at ARI standard rating conditions in close agreement: 0.95, 0.95 and 0.94, respectively.…”