The effect of building geometry on energy use

Energy service companies (ESCOs) use the Energy-Use Index (EUI) as a tool to evaluate a building's potential for reduction in energy use. Select Energy Services, Inc. (SESI) has found that consideration of building geometry is useful in evaluating a building's potential for energy use reduction. Building load and energy-use simulations using TRACE((R)) and PowerDOE((R)), respectively, were conducted to gain insight into how building geometry impacts Heating, Ventilation, and Air-Conditioning (HVAC) sizing and energy use. The ratio of gross wall area to gross floor area, A(wall)/A(floor) has been found to be a useful factor to consider when making EUI comparisons. Simulations suggest that buildings with higher A(wall)/A(floor) ratios require higher central plant capacities and use more energy per unit area to satisfy the heating and cooling loads. Taking a building's geometry (A(wall)/A(floor)) into account while estimating savings potential may produce more accurate results.