Window Energy Ratings for Chicago Homeowners

Chicago homeowners live in a climate that’s constantly changing and many months experience extreme conditions. With that being said, it’s important to have windows that’ll perform efficiently and feature the best window energy ratings.

window energy ratings

What are window energy ratings? In short, they’re the measurements that determine whether or not your windows can handle the climate they’re installed in. The main four ratings are u-factor, solar heat gain coefficient, visible transmittance and air leakage.

This may sound like a whole bunch of technical nonsense but we’ll go over what each one is and why they’re important when it comes to replacing your windows.

Why You Need Windows with Good Energy Ratings

Before we go into what the window energy ratings are and what they mean, you need to know why it’s important that your windows are energy efficient in the first place.

If your windows are old and worn out then you’ll be losing money every month from having to heavily rely on your heating and cooling systems to keep your home at a comfortable temperature.

This especially applies to homeowners in Chicago. The summers are long, hot and humid while the winters are snowy and unbearably cold. You need all the help you can get in order to stay comfortable during the peaks of summer and winter.

That’s why vinyl windows are the best recommendation for Chicago homeowners. Vinyl windows are made to withstand any weather extreme and will never crack, rot or warp, keeping your home sealed off from the outdoors.

What to Keep an Eye Out for with Replacement Windows

energy ratings for windows

Now that you know why you need energy efficient windows, you need to know how to decipher between the real and the fake.

Companies will often claim a bunch of accolades and features, but don’t have anything to back up the talk with.

There are a few different labels you need to keep an eye out for when comparing replacement windows.

The first and most important label you need to make sure the windows have is the Energy Star label. You’ve probably heard the name before as they cover a wide range of products from appliances to windows.

What that Energy Star label tells you is that the windows you’re looking at are certified for the climate that you live in. This is important because if you have windows that are more suited for tamer climates like the west coast, you’ll be in a world of trouble with those in Chicago.

The next label you need to make sure is featured on your windows is the National Fenestration Rating Council (NFRC) badge. The NFRC is responsible for measuring the energy efficiency and ratings of windows and is widely recognized across the industry.

The Different Energy Ratings

There are four main window energy ratings and all are equally important. A lot of companies will try and sell you on one or two that they claim are more important when the other ratings for their windows aren’t very good.

However, you need to pay attention to all ratings because only then will you be getting a product worth while. Below, we’ll go over each energy rating and how it plays a part in your window’s overall energy efficiency.


Your window’s u-factor determines its ability to keep heat inside a room. U-factor is measured in a range from 0.20-1.20. You want to look for low numbers because that means the window will be able to keep heat from escaping better.

Why is this important? For Chicago homeowners, you need your home to stay warm during the winter. You’ll need a window with as low of a u-factor as possible so that your heated air stays inside.

Visible Transmittance

Visible transmittance, or VT, is the measurement of how much natural light a window will let into your home. You might be thinking, “how can this be differentiated between different windows?”

Windows can have different VT because some might be letting in the harmful rays of the sun as well as some might have different tints of glass.

It’s rated on a scale of 0-1 with a higher number meaning more natural light will pass through your windows.

This is important because if a window can let in more natural light and less UV rays, you’ll be able to rely less on artificial light which can help you save money on electric bills.

Solar Heat Gain Coefficient

Also known as SHGC, solar heat gain coefficient measures the inverse of u-factor – how well your windows can keep heat out of your home.

It’s measured on a scale of 0-1 and the lower the number is, the better they can keep heat out. While u-factor is important for the winter, SHGC is important for the warmer months.

Windows with low solar heat gain coefficient will help you put less stress on your air conditioner which will bring energy costs down.

Air Leakage

You want your windows to be as air tight as possible. Nobody likes drafty windows. Air leakage is often overlooked when it comes to window energy ratings, but it’s actually very important.

Air leakage measures the amount of air that passes through the window structure itself. In order to be Energy Star certified, the number must be below 0.3. If the company doesn’t provide the rating, then their windows most likely don’t meet those standards.

This number does not take into account any gaps made during installation which is why you should always get your windows professionally installed.

Feldco Boasts Top Notch Window Energy Ratings

Now that you know what each window energy rating is and why it’s important, the next step is deciding what windows are best for your Chicago home.

The answer is simple. Feldco has been serving Chicago for over 40 years and has been recognized as America’s #1 Window and Door Company.

Our industry leading vinyl windows are the most energy efficient on the market. Energy Star certifications and excellent ratings across the board put us above the rest.

You’ll be saving money on energy bills in no time after having Feldco windows installed.

What are you waiting for? Get a free quote online and join the over 350,000 homeowners who count on Feldco for energy efficient replacement windows.

Copyright © 2023 Feldco Windows, Siding & Doors. All Rights Reserved.