Are slider windows warm enough for the Manitoba climate?
Although slider windows aren’t as efficient as casement style windows, they can still provide acceptable levels of performance in your home. As long as you get windows from the right company.
So how can you tell the difference? We’ll explain and break it down further in this post.
But first, here are the three things you need to know about slider windows:
- Although slider windows aren’t as efficient as casements, they can still provide acceptable levels of comfort and performance for a fraction of the cost.
- The main performance difference between the two types of windows is that slider windows use weather stripping, and casement windows rely on compression seals. When closed, windows with compression seals make an airtight unit are more efficient.
- When comparing slider windows you should consider BOTH, their heat loss conductivity (U-Factor) and energy rating (ER) for a true sense of how the window performs.
Should you get slider or casement windows?
As we mentioned above, the difference between compression seals and weather stripping is one of the biggest reasons for why slider don’t perform as well as casements. You can see for yourself how casement windows in Winnipeg compare between manufacturers.
Check out: Awning Windows in Winnipeg
What are tilt-and-turn windows?
When looking at slider windows, you may come across windows where the sash turns in, in a similar way it does in casement windows. Although this feature makes the windows look more modern and practical, its purpose is for cleaning and maintenance only. [hypotext target=”1″]Expand to read more[/hypotext] [hypotext id=”1″]The sash in slider windows can turn at a 90-degree angle into your house. This allows for cleaning of the outer side of the window from the inside of the house.
You shouldn’t keep the sash in a turned-in position as the weight of the sash can cause stress on the frame resulting in deformation or even breakage. This is especially crucial in triple pane slider windows because their sashes are much heavier.
When cleaning the sash, it is advisable to hold it at the bottom, so that the weight of the moving component doesn’t put stress on the frame.[/hypotext]
Comparing Slider Windows: What you should know
Regardless of the window company, style, or purpose, any windows you get for your home should meet ENERGY STAR requirements. In Canada, ENERGY STAR designated three unique climate zones. For each zone, a window must meet certain ER rating and U-Factor value in order to be considered efficient. Remember, a window is only considered efficient if it gains more heat than it loses. In order to be considered efficient, windows for Winnipeg must have a minimum ER rating of 29. [hypotext target=”2″]Expand to read about ER Ratings, U-Factor, and SHGC[/hypotext] [hypotext id=”2″]
ER Ratings are a value given to windows, based on a calculation of different performance factors. These include the U-Factor and Solar Heat Gains. The ER rating has been devised specifically to make it easier for consumers to understand and compare window performance from different manufacturers.
U-Factor is a calculation of how conductive a window is, how it is affected by convection heat loss and the emissivity of the glass in the panes. At the very basic level, the lower the U-factor, the better your window is at keeping heat inside the home.
SHGC: The Solar Heat Gain Coefficient measures how much heat from the sun a window gains. Although ideally, you want as much heat from the sun in the winter months, most modern windows with high SHGC end up overheating the home. High SHGC factors are great for windows that see very little direct sunlight and can maximize energy gains in those places. The lower SHGC, the less heat from the sun your windows let through.[/hypotext]
ER Ratings or U-Factor: What’s better for comparing windows?
Both of these values play an important role in determining whether any window is efficient enough for your local area. But which is a better representation? A window’s ER number can be significantly improved by higher SHGC factors. U-Factor on the other hand measures how resistant the window is to losing heat. [hypotext target=”3″]Expand[/hypotext][hypotext id=”3″]
An ER number is a more encompassing measure of how a window “transfers” energy. The more heat it gains rather than loses, the more efficient a window is considered. Therefore, it is always important to look at the SHGC number to see how it plays into the window rating.
The U-Factor on the other hand assesses a window’s resistance to heat loss. This is especially important to consider in Canada as we often have longer nights in the winter where it is essential for a home to retain as much of its heat as possible.[/hypotext]
We have compared slider window ratings from main Winnipeg companies: All Weather Windows, JELD-WEN, Polar Ray-o-Max, Duraco Windows, Ecoline Windows, and Canadian Choice Windows and Doors.
Below are the performance numbers for triple-pane single slider windows with a single application of low-e, from most popular vinyl window companies in Winnipeg. Besides the actual performance numbers, make sure to pay attention to the value ranges from each company. It is often possible to improve the performance of your windows with additional features.
Not seeing a window company you’re looking for? Information about all window performance values can be found for free on Natural Resources Canada website.
Why is information about some window companies missing?
As you have noticed, a couple of companies don’t have information available for their slider windows. This information is not listed under the company’s registry on the NRCan website.
This could mean one of two things: either slider windows from that company are not ENERGY STAR rated, or the company gets their slider windows from elsewhere. But usually, the former is true. Slider windows usually rank at the borderline levels of acceptable performance. That is why they often require additional features to improve their performance. As you can see by the chart some company’s slider windows barely reach that level, even with additions like Low-E and gas fills.
If you are replacing windows in your whole house, undoubtedly you will buy some slider windows. When that time comes, make sure that you only consider windows that meet climate requirements for your area.