The Effect of Vegetation on Residential Energy use in Ann Arbor, Michigan
Robert J. Laverne and Geoffrey McD. Lewis
Abstract: Computer models have shown that proper placement of trees around climate- controlled buildings can significantly contribute to energy conservation by lowering cooling requirements in summer months and heating requirements in the winter. A study conducted in a residential neighborhood of Ann Arbor, Michigan, uses electric and natural gas utility company records to examine energy demand for homes in 3 areas with distinctly different levels of tree stocking. Field measurements quantify the density of vegetation that casts shade directly on homes, and aerial photo interpretation is used to evaluate potential wind shielding offered to individual homes by vegetation and adjacent buildings. Statistical analysis of data indicates that variability of structures, including different levels of insulation, infiltration, and efficiencies of space-conditioning appliances mask the effects of vegetation on energy use. Analysis is further complicated by a wide range of energy use habits of individual homeowners. However, trends are observed that suggest proper placement of trees with regard to seasonal solar gain and wind patterns may yield substantial savings of energy. Improper placement of trees may yield a significant increase in net levels of energy used for space conditioning.