Report Number




HVAC; Buildings; Simulation; Heat Pumps; Heating


The University of Central Florida/Florida Solar Energy Center, in cooperation with the Electric Power Research Institute and several variable-refrigerant-flow air conditioning (VRF AC) manufacturers, provided a detailed computer model for a VRF AC system in the United States Department of Energy's (U.S. DOE) EnergyPlus' building energy simulation tool. No other simulation tool currently has the capability to accurately model this state-of-the-art VRF heating, ventilating, and air conditioning (HVAC) equipment. Detailed laboratory testing and field demonstrations were performed to measure equipment performance and compare this performance with that predicted by the use of this new model through computer simulation.

This project aims to fully understand the complex interactions of VRF AC systems from an HVAC system perspective, and investigate the interactions of this HVAC system type within a real world building environment. Detailed laboratory testing of this advanced HVAC system provided invaluable performance information which does not currently exist in the form required for proper analysis. This information could also be useful for developing and/or supporting test standards for VRF AC systems. Field testing VRF AC systems also provided performance and operational information pertaining to installation, system configuration, and operational controls.

Information collected from both laboratory and field tests were then used to validate the VRF AC system computer model which, in turn, provides architects, engineers, and building owners the justification necessary to accurately and reliably perform building energy simulations. This new VRF AC model available in the latest version of DOE's EnergyPlus software and can be used to investigate building energy use in both new and existing building stock and provide building owners and manufacturers alike the information needed to improve the baseline efficiency of commercial HVAC equipment and the building as a whole.

Date Published


Local Subjects

Heat Pumps; Heating; Buildings - HVAC; Simulation


FSEC Energy Research Center® Collection



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