There are so many things to consider when you are shopping for new windows. You want energy-efficient windows that will let the right amount of light in, without making the house too cold or too hot.

So, it’s important to understand the Solar Heat Gain Coefficient (SHGC) rating so that your windows make your house feel just right.

What Is Solar Heat Gain Coefficient?

The SHGC rating represents a small fraction of the amount of solar radiation across the entire spectrum directly transmitted and absorbed by the glass portion of a window. This gives you an idea of the window’s performance in terms of how much solar heat and sunlight will be released inside your home. Basically, the lower SHGC glass ratings mean a window has less solar heat gain and, therefore, better shading capability.

Why Is SHGC Important?

Solar heat gain, being the primary mode of energy transfer through most fenestration products, can lead to overheating in the summer and provide free heat in the winter. It’s essential to consider climate, the sun’s direction and typical shading conditions at your building’s location to balance and maximize the potential benefits.

When using the appropriate SHGC for the glass, given its location, orientation and angle relative to the sun, the building’s energy performance can be greatly improved by reducing its thermal load during the summer and gaining heat during the cold winter months.

Solar Heat-Gain Coefficient in Different Climates

The following are some recommendations of exterior services experts for the best window and skylight choices based on SHGC and the region of the U.S. where they will be used.

  • In colder, heating-dominated northern climates, SHGC is less important than a window’s U-factor, which can still be taken into account for energy efficiency.  When air conditioning is generally not of concern, a higher SHGC in the range of 0.30 to 0.60 can be helpful.

  • In the mixed climates of the North and Midwest, where both heating and cooling are used, but cooling is used less often, windows and skylights with an SHGC of less than 0.40 are best. In situations where air-conditioning costs during warm months can become high, windows with an SHGC of less than 0.30 can be beneficial.

  • In the mixed-climate South and central regions that use both heating and cooling, SHGC for windows and skylights is best kept under 0.30. Though, in areas where heating may be used extensively for some periods of the year, a lower SHGC equates to less warmth gained by solar heat.

Tri-County Contracting is a family-owned and -operated company located in Waukesha County. We are proud to be a full-service exterior remodeling contractor offering residential and commercial roof replacement and repair services.

Keep your home comfortable with quality and energy-efficient door and window replacement from Tri-County Contracting. For more information about our services and products, or to get your free project estimate, contact us at (262) 217-8150, or fill out our online form. We serve clients in Waukesha, WI.