Smart Windows

The Department of Energy reports that forty three percent of American houses have single pane windows, which are considered to be the least energy efficient of all types of windows. This means that a significant portion of Americans are losing money and wasting energy because they have not upgraded to energy saving windows.
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Energy saving windows typically have more than one pane, lamination, or other efficiency improvements.

Double Pane Windows: Double pane windows are made with two panes of glass, and a gas, usually argon, in between. Its insulative property keeps the warmth inside in the winter and the the heat out in the summer, which saves energy.


When looking for energy efficient windows, it’s a good idea to find ENERGY STAR qualified products.

Windows with the ENERGY STAR label meet the Environmental Protection Agency and Department of Energy’s requirements for U-Factor and Solar Heat Gain Coefficient (where applicable). This means that ENERGY STAR qualified windows meet strict energy efficiency requirements, and using these windows can lower household energy bills by 7-15%.

When looking for energy efficient windows, it’s a good idea to find ENERGY STAR qualified products.

Plus, ENERGY STAR windows can reduce fading of photographs, furniture and flooring by up to 75% because of their special Low-E coatings. They also have lessened potential for condensation inside the window because of their advanced frames, glass coatings and/or spacers.

Smart Windows

Smart windows are engineered to automatically change its tint based on the weather. In warmer air temperatures, it becomes tinted to prevent light and heat from entering the building. In cooler temperatures, they become transparent.

The following smart windows are currently available on the market:

1. RavenWindow from RavenBrick

RavenBrick’s RavenWindow is smart window that uses thermochromic technology to reduce energy costs by up to 30%. In fact, the company, which is based in Colorado, claims that is the product has twice the efficiency of the best energy efficient window on the market.

RavenWindow is easy to install in new or existing buildings, and is low maintenance once installed.

2. SageGlass

SageGlass is a smart window made from electrochromic glass, which means it can change tints electronically, either from pushing a button, using a built-in automation system, or using a building management system. This can produce a 20% savings in operational costs, decrease the size of the HVAC system by 25%, and reduce peak demand by 25%.

The product is manufactured by Sage Electrochromics, which calls itself the building industry’s “world leader in electrochromic glass”.

Window Retrofits

The following three window treatments are ideal for energy efficient retrofits.

1. Indow Windows

Indow Windows are inexpensive thermal window inserts that cost 80-85% less than a new double pane window, but can achieve up to 94% of the same energy savings as replacing a single pane window with one. At about $13 per square foot, the Indow Window is a cheap, easy way to improve your single pane window and achieve a 10-30% return on investment annually.

Plus, Indow Windows reduce noise transmission by 50% or more, and is almost invisible when installed on the window. It is made from acrylic glazing and spring bulb lining, which is free of PVCs.

Because of its ingenuity, the Indow Window was named one of the Top 10 Green Building Products of 2011 by Sustainable Industries.

2. iWindow Commercial Glass Retrofit

The iWindow, manufactured by Serious Energy, is a retrofit for commercial glass windows. It reduces heat gain by up to 2/3, retains heat by up to seven times more than a single pane window, and blocks 96-99.6% of UV rays, which saves energy and lessens fading. According to the company, the product improves the "full-frame R-value from R-0.8 up to R-3.9 (U-factor 1.2 to 0.255) and center of glass R-value from R-1.0 up to R-7.2 (U-factor 1.0 to 0.14)".

Plus, the iWindow reduces noise transmission.

The iWindow is 50-75% less expensive than replacing the window and takes 20 minutes or less to install, which makes it ideal for energy efficient retrofits.

3. Comfortex SilverScreen

Comfortex’ Window Fashions, a custom window treatment manufacturer based in Maplewood, New York, produces energy efficient window treatments made with SilverScreen fabrics. The fabrics have an ultra fine layer of aluminum on the back, which helps control temperature and drafts. You can still see through the window when the SilverScreen is pulled down, but it helps with glare and vision.

The SilverScreen, which is formaldehyde free, lowers energy use for heating and cooling by keeping light and heat out of the room in the summer and inside the room during the winter. It reflects 76% of solar radiation, and Comfortex says this can reduce heating costs by 10-25%.

Even more sustainable, the SilverScreen meets the Okeo-Tex 100 Standard for air quality.

How to Install Energy Efficient Windows

While certain window retrofits might be a do it yourself projects, installing new windows (or certain window treatments) is a job for a licensed, experienced contractor.


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