Module Development and Simulation of the Variable Refrigerant Flow Air Conditioning System under Cooling Conditions in Energyplus

Abstract

As a high-efficiency air conditioning scheme, the variable refrigerant flow (VRF) air-conditioning system is finding its way into medium-sized office buildings. Based on a generic dynamic building energy simulation environment, EnergyPlus, a new module is developed and the energy usage of the VRF system is investigated. This paper compares the energy consumption of the VRF system with that of two conventional air-conditioning systems, namely, the variable air volume (VAV) system and the fan-coil plus fresh air (FPFA) system. A generic office building is used to accommodate the different types of heating, ventilating, and air conditioning (HVAC) systems. Our objective is to examine the energy consumption of the VRF system applied to office buildings and make suggestions for evaluating and making decisions on HVAC systems in the early stages of building design. Simulation results show that the energy-saving potential of the VRF system is expected to achieve 22.2 percent and 11.7 percent, compared to the VAV system and the FPFA system, respectively. An energy-usage breakdown of electricity end-users in various systems is also presented.