DETERMINING THE FEASIBILITY OF GEOTHERMAL SYSTEMS

摘要

Geothermal or GeoExchange~(TM) systems are often found to be too expensive by designers and building owners. Because of poor paybacks many potential geothermal projects are simply built with conventional heating, ventilation and air conditioning (HVAC) systems. Even motivated building owners who really want to reduce the impact their buildings have on the environment will not build a system that does not show a reasonable return on their investment. This paper will focus on a methodologies and strategies to optimize the design of a geothermal system to reduce the cost of building the system and maximizing the system efficiency. It will show why and how the design process needed to develop a costeffective geothermal system differs from that of designing a conventional fossil fuel driven HVAC system and how embracing the integrated design process can have a dramatic impact on the economics of the system. This paper discusses three key aspects of system optimization: 1. Accurate energy modeling & the impact it can and needs to have on the design of the building. 2. Mechanical system design strategies and the impact they can have on the size and cost of the ground heat exchanger. 3. Impact of site and geology on ground heat exchanger configuration and design.Determining the feasibility of a geothermal system with this methodology provides the greatest opportunity for the building owner to realize a positive return on his or her investment. This results in a system with improved cash flow when compared to a conventional HVAC system as well as a system that is sustainable over the long term.