Paper Conference

Proceedings of BSA Conference 2017: Third Conference of IBPSA-Italy


A New Control Strategy for Variable Refrigerant Flow Systems

Xiaojie Lin, Yunho Hwang, Reinhard Radermacher, Byungsoon Kim

Abstract: In the US, more than 45 % of the building primary energy is used for space cooling, space heating, and water heating. Advanced HVAC systems are key to building energy consumption reduction. A variable refrigerant flow (VRF) system is a promising solution to this problem, because it can precisely provide space cooling and/or space heating for different zones. A literature review of previous VRF modeling studies shows that the use of existing simulation tools, such as EnergyPlus, can result in more than 20 % deviation in both capacity and energy consumption. In this study, a new VRF model is proposed to improve the accuracy over conventional models. Simulation results show that the proposed model agrees with experimental field test data within a 10 % deviation in hourly capacity and 5 % in hourly energy consumption. After the validation of the VRF system model, a new VRF control strategy was proposed based upon evaporating/condensing temperature controls. The seasonal performance of VRF system with the new control strategy was simulated for the same building design in four different climates representing these US cities: Miami, Houston, Baltimore, and Chicago.
Pages: 557 - 563