#Windows grid r driver#

For instance, in northern climates in winter, if windows reduce thermal losses and capture solar gains, they can become net-positive energy.ДЇor U.S. Unlike heating, cooling, and lighting systems where the typical design strategy is to reduce energy use to lower levels, windows have the potential to be zero net energy or even net-positive energy. High-performance windows can minimize solar heat gain in the summer to reduce cooling loads, admit solar heat and insulate against heat loss in the winter, reduce energy consumption for artificial lighting during the daytime, and reduce a buildingвЂ™s peak heating and cooling load. Better window technologies offer numerous energy savings opportunities and improved comfort.

In the winter, windows are poor insulators compared to walls and allow heat to leak from buildings, increasing heating loads on HVAC systems.

#Windows grid r driver#

This solar heat gain tends to be the major driver of summer afternoon cooling peaks-usually even a bigger driver than air temperature. In the summer, conventional windows allow heat from sunlight to enter buildings, increasing cooling load. This consumption is a result of thermal heat losses and gains across windows, air leakage, and transmission of solar heat into buildings. Selkowitz: Each year in the United States, windows are responsible for about 30 percent of the energy used to heat and cool buildings-about 4.1 quads-at a cost of $50 billion. Where are the opportunities for energy savings? Stephen Selkowitz EJ: Explain how todayвЂ™s windows and building faГ§ades result in significant energy losses.