<p> </p> <p class="MsoNormal" style="margin-bottom:0in;margin-bottom:.0001pt;text-align:
justify;line-height:200%;mso-layout-grid-align:none;text-autospace:none"><span style="font-family:"Times New Roman","serif";color:black;mso-bidi-font-style:
italic">This paper presents the theoretical investigation of effects of sub-cooling on </span><span style="font-family:"Times New Roman","serif";
color:black">the<span style="mso-bidi-font-style:italic"> performance of eco-friendly alternative refrigerants (R152a, RE170 (Dimethyl ether) in a </span>domestic<span style="mso-bidi-font-style:italic"> refrigeration system. The study was performed using a vapour compression system with the aim of finding a drop-in replacement for R134a. An increase in sub-cooling effectiveness reduces the compressors power and increases the system refrigeration effect. Also, an increase in the degree of sub-cooling, reduces the refrigerant mass flow rate, compressor power and increases</span> <span style="mso-bidi-font-style:italic">both the refrigerating effect and coefficient of performance (COP) of the</span> <span style="mso-bidi-font-style:italic">system. The comparison of the performance of R134a and the investigated alternative refrigerants showed that R152a and Dimethylether (DME) have the most similar performance characteristics to R134a with DME having better </span>performance<span style="mso-bidi-font-style:italic">. These two refrigerants are the best replacements for R134a in</span> <span style="mso-bidi-font-style:italic">a domestic refrigeration system. </span><span style="mso-spacerun:yes"> </span><o:p></o:p></span></p>