What Are Energy Efficient Windows And When Did They First Become Used In Homes?

What are energy efficient windows and when did they first become used in homes? There was an increase in interest in residential energy efficiency windows around the time of the first oil crisis. Energy...

Energy efficient windows are windows that are designed to provide energy savings. This is achieved by reducing heat loss, air drafts, and providing better thermal insulation using special materials such as fiberglass frames, double or triple panes of glass, low emittance coatings, and foam insulation within the framework of the windows.


Traditionally windows were made from a single pane of glass in a wooden frame. If you've ever lived in an older home with original wood frame windows you know how drafty they can be in the winter months. As technology advanced, aluminum and other types of steel were implemented as the preferred frame material. Further advancements led to the use of fiberglass and multiple panes of glass to create the most energy efficient windows possible, although energy efficient windows can still be made with wood or aluminum frames.




Thermotech representative Steven Poitz explains the development of energy efficient models in the window industry.

"In general, there was an increase in interest in residential energy efficiency around the time of the first oil crisis. In terms of window technology at that time, a lot of people who were interested in making energy-efficient windows changed from the normal two panes of glass to having three panes of glass in a window, which is called triple glazing. And then, in the intermediate 20 years or so, there have been a couple of other interesting developments including something called low-E glass, which could be translated to mean low energy but actually means low emittance. Low-E glass is glass that is covered with a very, very thin layer of metal. The metal is so thin that you can see through it, but it changes the heat transfer characteristics of the window so that it insulates instead of losing heat. If a window was double glazed with this special low-energy glass, it would insulate better than a triple glazed window."

Poitz has worked for Thermotech Windows since 1991. He is a professional engineer specializing in energy efficient windows and has a degree in mechanical engineering. He also sits on the Canadian Window Standards Subcommittee for energy performance in windows.

There are a number of different choices in framing, glazing, and low emittance coatings available when choosing energy efficient windows for your home. You can also customize your windows by color and size to fit your existing window openings. The Thermotech website (www.thermotechwindows.com) offers tools to help consumers determine which type of windows will best suit the needs of their individual home.

Energy efficient windows can cost more than conventional windows, but the savings in energy costs and increased comfort make them a good investment over their lifetime. In this interview, Poitz discusses where energy efficient windows provide the most benefit in your home, choosing the right windows, how to install energy efficient windows, and calculating the energy cost savings to be gained by energy efficient windows. You'll also learn other energy saving tips for your home and what to do if your double or triple glazed windows develop condensation between the panes.

© High Speed Ventures 2011