Growing concerns about the global warming impact of refrigerants used in HVAC&R equipment are driving development and evaluation of alternative refrigerants with lower global warming potentials (GWPs). The Air Conditioning, Heating, and Refrigeration Institute (AHRI) recently coordinated the Low-GWP Alternative Refrigerant Evaluation Program (AREP) in which commercial, university, and governmen...

The paper presents a study of refrigerants and some issues relating to their environmental impacts in HVAC&R equipment. They are treated aspects of the environmental pollution through the working fluids of the air-conditioning, refrigeration and heat pump systems, and a new strategy in using refrigerants in accordance with the international legislation is described. Additionally, this study pre...

The use of chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) has been widely restricted. They have been replaced with hydrofluorocarbons (HFCs) in order to protect the ozone layer. However, the leakage of refrigerant into the air from active or end-of-life air conditioners is a serious environmental issue owing to the high global warming potential (GWP) of HFCs. Therefore, replaci...

The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) recently completed the first phase of its low global warming potential alternative refrigerants evaluation program (Low-GWP AREP). This industry-wide cooperative research program identified and evaluated promising alternative refrigerants’ performance over the past two years. Thirty-eight low-GWP refrigerants were tested during t...

This study proposes the use of product design in the development of new refrigerants. Product design involves the use of consumer preference functions as described by Bagajewicz (2007). Consumer preference functions relate the satisfaction of consumers to different refrigerants based on their properties. The properties examined in this study were toxicity, flammability, explosion potential, glo...

The impending prodllction limitations on the fully halogenated CFG refrigerants is causing an intense search for possible substitutes. This study reviews the historical development of the CFG refrigerants and the relationship between molecular structure and t:he ozone depletio11 and greenhouse warming potentials. It then demonstrates that the halogenated hydrocarbons (a class of compounds that:...

The ongoing global effort to replace current refrigerants with zero Ozone Depletion Potential (ODP) and virtually zero Global Warming Potential (GWP) refrigerants has important implications for heat exchangers, air conditioning system design, and the materials choices in these designs. Natural refrigerants with higher flammability, CO2, HFOs, and HFC – HFO blends each place different requiremen...

The introduction of new refrigerants into the marketplace to replace CFC's banned by the Montreal Protocol has generated new research, required a review of many refrigeration concepts, and has raised new safety issues. One aspect that required further study occurred because some of the new refrigerants have a higher working pressure in the refrigeration and air conditioning equipment. This caus...

the present work is the successful extension of an improved equation of state (eos) to refrigerant fluids. the objective is the prediction of isothermal and saturated liquid densities of refrigerants. two temperature-independent parameters appearing in the modified eos are closely related to critical point properties of refrigerant fluids. our results showed that, the proposed eos can predict w...

Refrigerant blends and pure refrigerants have wide applicability in thermal engineering. One of the critical parameters in the design and evaluation of thermal equipment is the heat transfer coefficient, which can be difficult to determine for refrigerants that undergo phase change within the equipment. For pure refrigerants, classical experimental relations developed by Gungor and Winterton (G...