An updated energy study conducted by Dr. Joe Huang, a research scientist and president of the consulting group White Box Technologies, has reinforced an earlier study that awnings and exterior shades can provide significant savings on home cooling costs by reducing the load on air conditioners. The new study calculates the impact of awnings in 50 cities across the United States, and will be available to the public in late summer 2012. It also supports previous research, “Awnings in Residential Buildings, The Impact on Energy Use and Peak Demand,” a study conducted in 2007 by the Center for Sustainable Building Research, University of Minnesota.
According to the updated analysis, in a hot year, awnings can reduce annual cooling energy by more than 52 percent, compared to homes with completely unshaded windows. The amount of cooling energy saved varies depending on the number of windows, type of glass in the windows, window orientation and the climate of the region. This can amount to as much as $200 or more in energy savings for home homes with equal window distribution having single or double pane windows.
For instance, in Fort Worth, Texas, in a house with awnings, cooling energy use can be reduced by as much as 16–25 percent compared to the same house without awnings. Both cooling energy savings and peak demand reductions are largest on homes with west-facing awnings.
“People now realize that cooling energy is lost through glass doors and windows,” said Michelle Sahlin, managing director of PAMA. “This study bolsters the fact that awnings and exterior shades are an effective method to reduce heat gain and cooling energy costs.”
The updated study, commissioned by the Professional Awning Manufacturers Association (PAMA), increases the number of variations (cities, shade designs and fabrics). White Box Technologies also incorporated updated information about weather and energy costs, and includes improvements to the simulation model.