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Answering Your FAQs About Energy-Efficient Windows

Energy efficiency is one of the most important qualities you should look for in your replacement window. With this, your indoor living spaces remain comfortable while saving on heating and cooling costs. You may already have a specific window style and type in mind, but you may find it challenging to choose the most efficient one on the market.  

Answering Your FAQs About Energy-Efficient Windows

To help you learn more about energy-efficient windows, Renewal by Andersen® of Rapid City answers frequently asked questions about them.

What Is an Insulated Glass Unit?

An insulated glass unit or IGU combines multiple panes of glass with spacer material and gas sealed in a frame into one window system. Thanks to the multiple panes of glass, your window provides greater thermal efficiency as it has extra barriers to heat and cold transfer.

What Is a Gas-Filled Window?

In modern window technology, most windows seal an inert gas –  typically argon –  between the panes of glass to make your window more energy efficient. Compared to air, the argon is a much better insulator and further increases the window’s thermal value. 

What Does Low-e Glass Mean?

Low-e means low emittance or emissivity. This means that the glass is coated with a virtually clear material that cuts the transmission of ultraviolet rays from the outside to the inside. To improve the thermal efficiency of the window, low-E glass cuts the glare and prevents the damage that UV rays can cause to your interior furnishings. If you live in a region with hot summers, low-E windows can help you save money on your air conditioning bill. 

What Is the Difference Between R-value and U-value?

In general, R-value is used when discussing information such as wall and ceiling insulation values. However, it does not work well when it comes to windows and other fenestration products. As such, U-value is used in published material on windows. Take note that R-value and U-value ratings relate to each other inversely. A higher R-value means walls and ceilings are better insulated, while a lower U-value indicates that the window does a better job at keeping out the heat and cold.

Get in touch with Renewal by Andersen of Rapid City when you need energy-efficient window and door replacement services. To learn more, call us today at (605) 341-7831 or fill out our contact form to set an appointment. We proudly serve homeowners in Spearfish, SD, and the surrounding South Dakota communities.


"We recently replaced all of the windows in our home. I was most impressed with the friendly staff who knew what I wanted before I did. They seemed to be able to find the perfect window for each one we replaced. We are very pleased with the result. From beginning to end they were professional and helpful. I would highly recommend Renewal by Anderson."

Sheila And Doug Cain
May 15

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