Modeling and experiment analysis of variable refrigerant flow air-conditioning systems

This study developed a component-based gray-box model for variable refrigerant flow (VRF) airconditioning systems to simulate and predict the performance and energy consumption of VRF system in cooling condition. Results from the testing of Daikin’s 10HP VRV system with six indoor units, as well as the manufacturer’s data, were used to fit the key parameters of each component in this VRF model. This model was integrated in the building energy simulation software DeST and was validated by using data both from Daikin’s product handbook and from tested results. The validation results showed that this model can be used to calculate the coefficient of performance (COP) of VRF systems in an error of less than 15%.