Experimental Study on Performance Parameters for Refrigerants R22, R410a and R404a at Various Air Outlet Temperatures P. Nagaraju P. G. Student Department of Mechanical Engineering Sanketika Institute of Technology and Management Visakhapatnam, India Ch. Kiran Kumar Associate Professor Department of Mechanical Engineering Sanketika Institute of Technology and Management Visakhapatnam, India M. V. N. Srujan Manohar Assistant Professor Department of Mechanical Engineering GVP College of Engineering (A) Visakhapatnam, India Abstract— The motivation of this project is to investigate the performance parameters of R22, R410A and R404A refrigerants at various air outlet temperatures. The performance parameters include various thermodynamic properties like maximum discharge pressure, coefficient of performance, power consumption, heat rejection and mass flow rate. Normally for all refrigerants, thermodynamic properties decrease on achieving less temperature. As R410A is now widely used refrigerant, but on experimentation it has been observed that R404A has reached the desired temperature in short time and having highest mass flow rate when compared with R410A and R22 at four different air outlet temperatures and also there is a slight comparison observed on remaining thermodynamic properties for R410A and R404A. Keywords— Mass flow rate, Coefficient of performance, Power, Refrigerating effect, Ozone depletion potential I. INTRODUCTION A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle. In most cycles it undergoes phase transitions from a liquid to gas and back again. The first known instance of refrigeration was demonstrated in 1748, by William Cullen at Glasgow University. After that, in the early 19th century compression was made on the ammonia vapour into a liquid by Michael Faraday, and then followed the invention of the first refrigerator. Since the rise of climate control technologies in the 20th century the issue of environmental impact become a major concern. The main impetus was of course the ozone depleting potential of the chlorofluorocarbons (CFCs) and hydro-chlorofluorocarbons (HCFCs) commonly used in refrigeration. The HCFCs, including R-22, were scheduled for phase-out in 2010, even while bridging the development of refrigerants from early CFCs to modern hydro fluorocarbons (HFCs). The HFCs are accepted because they contain basically zero ozone depletion potential (ODP). Thus the requirement for environmentally friendly, working refrigerants necessitated the invention of refrigerant R-410A by 1991 which was introduced by Honeywell. Since then R- 410A performance has been researched in various applications. Another HFC refrigerant comparable to R-410A is R-404A. Refrigerant R-404A was developed to replace CFC R-502 and HCFC R-22. A window air conditioner is a system that cools space to a temperature lower than the surroundings. In air conditioner heat must be removed from the enclosed space and dissipated into the surroundings. However, heat tends to flow from an area of high temperature to that of a lower temperature. During the cycle, a substance called the refrigerant circulates continuously through four stages. The first stage is called Evaporation and it is here that the refrigerant cools the enclosed space by absorbing heat. Next, during the Compression stage, the pressure of the refrigerant is increased, which raises the temperature above that of the surroundings. As this hot refrigerant moves through the next stage, Condensation, the natural direction of heat flow allows the release of energy into the surrounding air. Finally, during the Expansion phase, the refrigerant temperature and pressure are lowered by adiabatic expansion process. This cold refrigerant then begins the Evaporation stage again, removing more heat from the enclosed space. A typical diagram of a window air conditioner which works according to the process explained above is shown in the figure. International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 www.ijert.org IJERTV4IS110372 (This work is licensed under a Creative Commons Attribution 4.0 International License.) Vol. 4 Issue 11, November-2015 348