Variable-Refrigerant-Flow Cooling-Systems Performance at Different Operation-Pressures and Types-of-Refrigerants

This paper aims to study the performance of the Variable Refrigerant Flow (VRF) system under various conditions in hot and humid climates such as Abu Dhabi, in the United Arab Emirates. The model is built on Engineering Equation Solver (EES) with input data obtained from the specifications of the VRF units used, and the design requirements from the Masdar City Eco-Villa for which the model is done. A number of parametric studies are done on the VRF cycle model, such as, the variation of low and high pressures, in addition to, the variation of the type of working fluid used. Results have shown that the coefficient of performance (COP) of the cooling cycle is highly dependent on the evaporator and condenser pressures, as well as, the type of refrigerant used as working fluid. Finally, by evaluating the effect of each parameter on the COP of the system, the expected amount of energy savings can be increased.