If you are just getting started with window replacement or building a new home, you might be surprised to see labels on your windows when you buy them. These labels are as important as every other part of the window because in them lies the manufacturer, industry, energy, and performance information.

Hence, reading the information contained on a window label is one of the best ways to understand the performance features of the window. Apart from that, it will also help you to make an informed decision when doing a window replacement.

Seeing how important the window label is, the window installation experts at Window World Twin Cities are here to explain what the labels mean on your windows!

Energy Efficiency

Windows come with an energy efficiency logo. This is often represented in the Energy Star® symbol from the U.S. Environmental Protection Agency (EPA). The energy efficiency description on your windows label shows that the window brand meets your state’s energy requirement or standard.


The U-factor provides information on how the window handles insulation. Checking the U-factor is important because it helps you understand the sum of heat that can pass through the window. For an average homeowner, you may need to work with an expert window installer to help you understand this aspect of window label.

Visible Transmittance (VT)

The information on how much light passes through your window is contained in the visible transmittance area of the label. The VT is measured from 0 to higher numbers. The higher the VT number, the higher the amount of light that will pass through the window brand.

Solar Heat Gain Coefficient (SHGC)

To get information on how much heat your window lets into the structure, check the SHGC. Windows are built to reduce the sun’s radiation effectively. So, check the window you are buying to understand its efficiency in handling ultraviolet radiation.

The SHGC is often represented with a rating from .15 to .80. If your window has a higher SHGC, it may permit more heat into your structure.

Air Leakage (AL)

On the window label, the air leakage gives you information on how much air the window can let into your building. The AL typically comes with a rating of .1 - .03. The lower the rating, the lesser air your window can let in due to tight sealing.

Twin Cities Window Installation Experts

Are you up for a window replacement in the Twin Cities? Working with Window World might save you from making costly mistakes in the quality of windows you need and the installation process. We have well-trained windows repair and installation professionals ready to get on your window replacement projects.

Get started today by scheduling a meeting with one of our experts or get a free estimate for your project from the comfort of your home. You can also reach us at 651-770-5570 for a quick call. 

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