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GSHP & Building Energy Performance M&V


The world’s total primary energy consumption increased about 74% over 28 years from 1980 to 2008. At the same time, the primary energy consumption in the United States (U.S.) grew about 30% in demand, while the U.S. consumed about one fifth of the total world’s energy. Residential and commercial buildings consumed about 40% of the nation’s total energy, dividing it about half by each sector. In terms of electricity consumption, buildings consumed about 70% of total.

Much more than half (about 58%) of the total energy used for buildings was lost due to the conversion inefficiencies, from the source to the end use. The remaining less than half (about only 42%) of the total energy were utilized for productive purposes. So, improving energy efficiency should be a major goal for each segment; i.e., energy production, distribution, and use. The savings from the energy lost can be in the form of various energy efficiency optimizations starting from production to delivery. In case of the energy use, we have to consider alternatives and various methods, which reduce the energy requirement of all sectors of the energy economy, especially of the “building” sectors. As one of the most energy efficient and “green” HVAC systems, GSHPs have been widely used since a Swiss patent was issued in 1912 to Heinrich Zoelly as the first known reference to GSHP systems.

Although the benefits of GSHP systems have been verified, there are still some key barriers to implement; such as 1) high equipment costs compared to ASHPs, 2) difficulty of assessing the suitability of individual installation sites, 3) requirement of installation-specific design and engineering of the ground loop, and 4) space requirements for ground coupling in densely built areas. Due to these factors, it is important for designers and engineers to evaluate the cost-effectiveness of this technology implementation to their project. For example, drilling cost is more important to payback than thermal conductivity, although, both are important factors.

The goal of this research is to improve the energy efficiency of residential buildings through optimal design of GSHP systems in North Carolina.