Installing High Efficiency Replacement Windows

Improving the energy efficiency of your home brings about many challenges and may have you asking questions like: "Where do I start?" or "What do I do first?"

Replacement windows are one of the most advertised energy conservation improvements, but are they really the best investment? How do you know if you need new windows? What makes a replacement window truly energy efficient?

Larry Janesky, owner and founder of Dr. Energy Saver, is On the Job again, for one more episode that is all about windows!

The owner of this 1994 home had no doubts about the need to have all the existing wooden windows replaced by high efficiency replacement windows. There was so much air leakage from the windows that he could actually feel the draft by standing next to them. To make matters worse, some of the sashes were also beginning to rot.

When examining the closed window from the interior on a bright day, it was possible to see daylight coming through gaps in the frame; a tell-tale sign that the window wasn't sealed well. They were thermal pane windows, but made with clear, low performance glass that lets a lot of radiant energy heat from the sun into the house.

"If you are sitting in front of your windows and you feel heat coming in on your skin and warming the surfaces on your house, you do not have high performance glass windows," explains Larry.

High efficiency replacement windows have high performance glass to block the infrared rays -- or heat part of the solar spectrum -- from coming through the glass, while letting most of the visible light through. In the winter time, high performance glass prevents heat from the inside of the home to be transferred to the outside as well.

Larry then walked us through the process of removing the existing windows and installing the new, high efficiency replacements− a process that involves careful fitting of the window, and sealing of any gaps around it with spray foam to stop air leakage.
After the new windows were in place, Larry explained how to read energy efficiency labels on windows.

The numbers on the labels found on high efficiency windows tell us things like how much air can leak through them and how much visible sun light will pass through.
The Energy Efficiency numbers tell us how much heat can be gained through the window and the most important measurement -- the U-Factor -- tells you how energy efficient the window is when you add up the high performance glass panes and the frame; the lower the number, the better.

High efficiency windows can have a U-Factor as low as 0.15, but the windows installed in this project had a 0.29 U-Factor -- a significant improvement from the old windows, which might have had a U-Factor of 0.80 at best.

At Dr. Energy Saver we are always looking for new products, processes and technologies that will help make your home more comfortable and your energy bills much lower. We have helped thousands of homeowners nationwide, and we would love to help you too! Visit our website or give us a call to schedule a comprehensive home energy evaluation or a free estimate for replacements and upgrades!