Based on sustainable development,CO_2 emerges as one of the most likely alternatives to the synthetic fluids in heat pump water heaters.

This paper discusses a simple method which is able to provide the COP and the capacity of a theoretical refrigerating cycle using alternatives as working fluids, by means of some new relative factors such as the reduced difference of the cycle temperature, the reduced suction temperature and subcooling temperature.

Experimental study on performance of air source heat pumps with alternative refrigerants;

In this paper, experimental studies are carried out on the suitability of alternative refrigerants of R32/R134a and R407C with polyester type lubricants of different models.

The refrigerator performance tests have been carried out using refrigerant CFC12 and its alternative refrigerant HFC152a/HCFC22.

Based on the steady state distributed parameters model of the condensers which was put forward in the previous related reference the heat transfer and flow characteristics of four different two-rows condensers which used the refrigerant replacement(R407C,R410A,R134A)of R22 were studied.

In order to solve the problem existing when using themain refrigerant alternative (R134a) to substitute R12 in a refrigerator,this paper presents a solution of using R134a with R600a as a newrefrigerant R134a/ R600a.

On the research of alternative refrigerants, because of their advantageous thermal characters and unparalleled prepondrance of environmental protection, kinds of HCs substance have taken more and more scholars attention.

In order to study the alternatives in these heat pumps, thermodynamic properties and performance for alternative R32/134a were analyzed.

Such latest researches as the profile of scroll compressor, scroll mechanism, thermodynamic analysis and refrigerant replacement were summarized.