Chillers have typically been thought of as providing cold water to cooling coils located in a variety of air-handling systems throughout a building. However, there are certain building owners and operators who put a high value on energy reduction and sustainability. Heat recovery chillers (HRC) and water-to-water heat pumps are one way to improve the energy efficiency of a building’s mechanical system, as these systems reuse the energy in the system before the energy is rejected to the atmosphere.
It’s important to find an accurate method to calculate the power consumption of an HRC to better validate system efficiency. Most energy modeling software on the market does not support the simulation of an HRC system, especially when the chilled water source is supplied from a variable temperature campus loop. This is the challenge the authors faced during a recent project, as they worked to develop a way to accurately model these systems. This article explains how to accurately model an HRC system that is connected to a variable temperature campus water loop.