What is the Energy Star Certification And Why Is It Important?
Dec 18 2018
Posted ByOntario Window Reviews
In Canada, homeowners are especially aware of ways to save money on heating and keeping the bitter winter cold outside.
This can be done with proper insulation, an effective heating system, and well built doors. Another big area where you can save on energy and heating costs is with your windows.
To help consumers choose the most energy efficient windows on the market, the Ontario government developed the Energy Star Certification which can be seen on a range of windows.
So what exactly is the Energy Star Certification and why should you care about it?
If you are looking to improve your home’s efficiency, getting Energy Star Certified windows is a great first step. Let’s take a look and what this standard is and why it’s important.
What is the Energy Star Certification?
Firstly, let’s discuss what exactly the Energy Star Certification means.
The Energy Star Certification is a government program designed to highlight the top 15-30% of products that meet the highest standards for energy efficiency. The certification can be applied to any range of consumer products including appliances, building materials, doors, and windows.
The rating goes from one to five stars, with one being the least energy efficient and five being the most. Each product type will have a different set of criteria for what constitutes energy efficiency, such as yearly energy consumption or heat retention.
For windows, the main criteria for energy efficiency is based on a heat-loss test, air leakage test, and potential solar gain. The heat-loss test determines how much heat is lost through the windows, while the air-leakage test determines how good the seal is on a window and weather any cold air leaks in. The potential solar gain test refers to how much heat the window retains from exposure to sunlight.
Why is it important?
If you are looking to improve the energy efficiency of your home, installing highly rated windows is an ideal and cost effective way to begin.
Windows tend to occupy 15-20% of the wall space in a home, which makes them a significant source of heat loss in the home. It is estimated that in 1990 in the United States, unwanted heat-loss from windows cost consumers $20 billion USD, or nearly 25% of all energy and heating costs across the country.
Selecting a window that minimises heat-loss and air leaking is thus not only a comfort concern, but a financial one too. There are several factors that can contribute to the energy-efficiency of a window.
Single or Double Pane
The thickness of a window is directly proportional to how much heat is lost through it via radiation.
The thinner a window, the more heat it loses as the distance between the cold outside and the warm inside is small. Conversely, the thicker a window the less heat it loses, as the heat has to travel through more glass to radiate outwards.
Many Canadian home have been aware of this for decades, which is why double pane windows are common throughout the country. Having not just one, but two panes of glass separating your home from the outside is a great way to improve the energy efficiency of your home. Many double paned windows also contain a thin layer of gas between the panes, typically an inert gas with low heat conductivity such as argon. This adds an extra layer of protection to heat-loss by insulating your home.
Low Solar Heat Gain Coefficient Glass
Another important metric for measuring the efficiency of a window is its Solar Heat Gain Coefficient (SHGC).
This is a measurement of the amount of heat a window retains from solar radiation, which can impact the efficiency of a window during summer when the interior of the home is usually colder.
Having low SHGC glass installed in your windows will mean that less energy needs to be spent on cooling your home during the warmer months, saving you money in the long run.
Another way in which windows can improve their energy efficiency is by having a low-e coating applied.
Low-e coatings are special epoxies that are designed to lower the amount of ultraviolet and infrared radiation that is transmitted through a glass window without impacting the amount of visible light it lets in.
Similar to using low SHGC glass, having a low-e coating applied to your windows will help prevent heat retention during the summer so that your air conditioning system doesn’t have to work as hard to keep your home cool.
One area not many people are aware of when it comes energy efficiency is the type of frame used in your windows.
Aluminum frames tend to be the worst for energy efficiency, as aluminum is one of the most heat conductive metals used in construction. This means that when it is hot outside, the frame will heat up and transmit that heat in to your home. On the other hand, when it is cold outside, the frame will cool down significantly and radiate that loss of heat inside.
Using wood or vinyl window frames is ideal for increasing the energy efficiency of your home, as these materials have relatively low heat conductivity and are thus resistant to large changes in temperature.