Quality Window & Door Blog

Which Windows Have the Best Low-E Rating?

If you’re shopping for replacement windows, you want your investment to improve the comfort and efficiency of your home. At Quality Window & Door, we strive to supply our customers with the highest performance window products available today. One way to ensure you’re choosing an efficient option is to find windows with a low-E coating. Here’s more information about this technology and how to find windows that feature it.

What Is a Low-E Coating?

Low-emissivity, or low-E, is a coating many manufacturers add to their windows. This microscopically thin metallic oxide coating is applied directly to the inner surfaces of double- or triple-pane windows during the manufacturing process. The purpose is to reflect heat back to its source rather than transferring it through the window.

Benefits of Low-E Glass

  • Low-E reduces solar heat gain in the summer and reflects heat back inside your home during the winter, lowering your heating and cooling bills all year round.
  • Low-E reduces the amount of UV rays that enter your home, thus protecting your carpet, furniture, textiles, and wall coverings from fading.
  • Many types of low-E coatings reflect heat without drastically reducing the amount of light that the enters through the windows. This allows you to still enjoy a naturally lit home and lower lighting costs.

How to Find Windows with the Best Low-E Rating

Low-E glass comes in many forms. The coating can be applied to one or multiple panes of glass, and different types of coatings are designed to allow for high, moderate, or low solar heat gain in cold, temperate, or hot climates. This means that not all windows with a low-E coating provide the same level of performance.

To help you compare your options, first check out the window’s U-factor, which is the rate at which the window conducts non-solar heat flow. Ratings typically fall between 0.25 and 1.25, and the lower the rating, the better the low-E coating.

Also consider the solar heat gain coefficient (SHGC), which is the amount of solar radiation that passes through a window, measured between 0 and 1. Products with higher SHGC ratings are good for north-facing windows to collect more heat during the winter, and lower SHGC ratings are better for reducing solar heat gain through south-facing windows in the summer.

Another rating to consider is the visible transmittance (VT), which is measured between 0 and 1. Some low-E coatings are more transparent than others. Choosing a window with a spectrally selective low-E coating allows as much natural light to enter as possible. This means you should look for windows with a VT rating as close to 1 as possible.

Examples of Windows with Good Low-E Ratings

Infinity from Marvin is one brand that emphasizes energy efficiency. Many of the windows from this manufacturer are ENERGY STAR qualified across the entire country, regardless of climate. Choose an Infinity from Marvin window with low-E glass, and you can expect to reduce your heating and cooling bills by up to 30 percent.

Weather Shield is another quality window manufacturer that prioritizes energy efficiency. Windows with the Zo-e-shield glass solution provide the most impressive results. These feature multiple low-E coatings to block up to 99.9 percent of UV rays, producing some of the lowest U-factor and SHGC ratings in the industry.

Install Windows with the Best Low-E Rating in MD, DC & VA

To compare windows with some of the best low-E coatings in the industry, contact Quality Window & Door, or come visit one of our local showrooms in Maryland and Northern Virginia. We install high-efficiency windows and doors in homes and businesses across DC, Maryland, and Virginia.

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