Assessment of district energy integration between buildings

Abstract

District heating or cooling is a system for distributing heat or chilled water in a centralized location through various systems which is intended for residential and commercial heating or cooling requirements. Montana State University (MSU) is looking at implementing a future energy district in form of a distributed heat pump model. Implementing such system will help in reducing carbon emissions in the atmosphere, provide energy savings and ensuring energy is being used efficiently. In the summer season, there is a lack of substantial heat sinks in which heat could be utilized and in the winter season there is a lack of substantial heat sources available due to the extreme cold weather. This project identifies systems that serves as heat sinks and sources in buildings and provides substantial energy. This project also looks into the feasibility of connecting such systems together in a building to follow a recirculating heat pump model which operates in the temperature range of 60°F - 90°F. If this model provides much energy saving opportunities, it could be incorporated in buildings on campus here at MSU and connected to the future energy district. The project scope was limited to Barnard Hall, in which heat sources opportunities identified include the building exhaust air system and the process cooling system while heat sink opportunities identified include the domestic hot water system and the outdoor air that needs to be pre heated majority of the time in Bozeman, Montana. Energy calculations were done for each system and imputed into TRNSYS, an extremely flexible graphically based software used to simulate the behavior of transient systems. The heat pump model was then designed and simulated for a time frame of 8760 hours (A year). The researched showed that this provided some energy savings opportunities and yields no profit in general.