Everything You Need to Know About the Energy Star Rating System


Energy Use and Loss

Panes of glass offer all of us a window onto the world. From the inner comfort of our homes, offices, cottages, or wherever else, glass windows and doors are a portal through which we can enjoy the aesthetic and calmness of the outdoors.

Glass windows and doors are also what allow natural light to flood the interior of our living spaces. In the depths of winter, natural light isn’t just a nice-to-have; it’s essential to our mental health and wellbeing. Studies have found natural light boosts vitamin D, improves our sleep, and helps ward off seasonal depression. So, windows and doors aren’t just accessories; they are critical components that make our houses feel like homes.

However, along with the benefits glass offers our lives and homes every day, it can also be responsible for significant energy loss. The energy lost through the glass in your home’s windows and doors is directly responsible for up to 30% of your energy use when it comes to heating and cooling your home.

If your windows and doors aren’t energy efficient, you’re letting heat enter in the summer and cold enter in the winter. Unfortunately, this means you have to keep turning your heat or air conditioner up higher to maintain a comfortable and consistent temperature. And with energy costs rising, this is not a position you want to put yourself in. On top of that, using more non-renewable energy for heating and cooling our homes is terrible for the environment, something we are all more conscious of these days.

If we still want to enjoy the views of the outdoors from the comfort of the indoors, what can we do to mitigate the amount of energy we are wasting with glass windows and doors?

Energy Star Rating System

Chances are you’ve come across the Energy Star logo on some piece of technology around your house. In particular, appliance manufacturers have made a concerted effort to participate in the program, so it’s likely your fridge, oven, dishwasher, etc., have an Energy Star logo somewhere on them. But did you know that window and door manufacturers can also get their products certified?Energy Star Logo

The Energy Star rating gets awarded to products and services that meet a certain threshold of energy efficiency – meaning these products help reduce your household carbon footprint while also making a positive impact on your wallet in the long run.

Energy Star products are designed to help consumers use less energy. In 2020 alone, when home appliances were being used more than ever, Energy Star certified products saved enough energy to power over 392,000 homes for a year – equivalent to removing roughly 825,000 cars from the road!

An Energy Star rating is the gold standard in energy efficiency. By choosing a product that meets this standard, you are helping yourself through cost savings and helping the planet by consuming less energy.

Getting Energy Star Certified

For a window or door to earn the Energy Star rating, it must meet a certain standard on three performance metrics: U-Factor, Solar Heat Gain Coefficient, and Air Leakage. The minimum values a window or door must meet for these metrics changes based on the amount of glazing on the glass and where the product will be used. The ratings can also change over the years as new materials and technologies raise the bar higher for existing standards.

1. U-Factor

Measures how quickly heat is transferred through a given area of the glass. This value is used to determine the total amount of heat transfer due to conduction, convection, and long-wave infra-red radiation. The lower the U-factor, the better the window or door is at keeping heat in (during the winter) or out (during the summer).

2. Solar Heat Gain Coefficient (SGHC)

The ratio of solar heat entering the space through the glass to the incident solar radiation. Essentially, this measures how much solar radiation is allowed through the glass panel which, in turn, is converted to heat inside the home. This ratio should be as low as possible to ensure that the glass doesn’t let excess heat enter the home.

3. Air Leakage
Measures the amount of air flowing through a given glass area over time due to differences in air pressure or temperature on either side of the glass. Think of the air that flows through cracks or gaps where the glass panel meets the door or window frame. Again, the lower the air leakage value, the better.

If a window or door meets or surpasses all three of these metrics, it receives the Energy Star certification from the appropriate government partner. For example, in Canada, Energy Star has a voluntary partnership with the Government of Canada through Natural Resources Canada (NRCan) to support the program and help make high-efficiency products available and visible to Canadians.

Make the Right Choice for Your Home

The next time you’re looking for a window or patio door, make sure you look for one that has been Energy Star certified. At Sunview, 6 of our vinyl patio door lines are Energy Star certified, either as a standard configuration or on select models. We also offer Energy Star compliance options on the 2900 Aluminum and 2900 Hybrid series doors.

It’s not just windows and doors either. Anything in your home that uses or influences your power usage has the potential to earn the logo. By incorporating Energy Star into your home, you’ll be making your home more energy-efficient, which is good for the environment and helps keep your bills down!

If you’re interested in learning more about our products, you can visit our product pages here or reach out to one of our partners in your area!