Which Windows Perform Best in Cold Weather?
In a climate that changes so drastically from summer to winter, Canadian homeowners need windows that are durable and energy-efficient at all times. Therefore, the best window for cold weather will deliver in three key areas:
- A durable, reinforced, efficient window frame
- Airtight seal and proper insulation
- Natural light and heat transmittance
Why are these factors important? Aging, faulty, leaky, improperly sealed windows can be a major source of unnecessary heat loss, high home energy consumption, cold drafts and lead to condensation problems. In fact, windows can account for up to 25 percent of the total heat loss for a home.
Let’s dig a little deeper into these key areas and also which pieces of window technology can help your units deliver premium performance for years to come, even throughout the most bitter Canadian winters.
1. The Best Windows for Cold Weather Have Reinforced, Thermally Efficient Frames
The strength and thermal efficiency of your window frames are essential during the winter months. So, when it comes to the frame, what is the best window for cold weather made of? To answer this question, let’s start by looking at two popular window frame materials:
Vinyl PVC Window Frames:
Vinyl PVC is the most popular frame material on the market today. This is understandable: window replacement is an expensive process and homeowners looking to save money are naturally attracted to vinyl’s very low upfront cost. Defenders of vinyl windows will also tell you that they are highly thermally efficient, which is true. As a material, vinyl PVC has a very low thermal conductivity, meaning that heat or cold has a very hard time transferring through the material. It’s also possible to weld the corners of the frame together to create an air- and water-tight seal.
That said, vinyl PVC also comes with major structural flaws. These frames lack strength, rigidity, and durability and are susceptible to expansion and contraction in the heat of Canadian summers and winters.
Aluminum Window Frames:
In contrast to vinyl PVC, aluminum is a very strong, durable window frame material. Because of their strength, aluminum frames can be thinner than vinyl frames without sacrificing strength. That said, aluminum windows have a very high thermal conductivity, meaning that heat transfers very easily through the material. While weatherstripping and thermal breaks can help, standalone aluminum frames are not an effective means of insulation in cold weather climates.
Combining These Two Materials Leads to Stronger, More Efficient Frames
While both vinyl and aluminum have weaknesses, they also have advantages when it comes to managing cold weather: the strength and durability of aluminum; the insulation, and welded corners of vinyl PVC.
In this way, vinyl PVC frames that are reinforced with stronger materials like aluminum and galvanized steel can deliver excellent performance in colder climates. They provide all the thermal insulation of vinyl PVC, without running the risk of expansion and contraction due to the durability of steel and aluminum.
2. The Best Window for Cold Weather Stays Sealed and Well-Insulated
In addition to a thermally-efficient frame, the window’s glass component must be able to insulate. An insulated glass unit (IGU) is key to ensuring that your home is able to keep the heat in and the cold out during the winter months.
The energy efficiency metric that helps measure how well a window can prevent heat loss is called U-Factor. This makes it a very good indicator of the insulating properties of a window. One way to improve U-Factor and create a more insulated window unit is by using gas fills.
What are Gas Fills?
To create an insulated glass unit (IGU), manufacturers will fill the space between the window’s glass units with krypton, argon, or xenon gas. These heavier, noble gases are preferable to filling the unit with air because they can better impede the transfer of heat through a window.
The Magic™ Difference: Most IGUs on the market are separated by ½ – ¾ of an inch. Due to our innovative approach to window hardware design, we are able to extend that space to a full inch. This means we can fill our IGUs with 25%-50% more gas. More gas leads to more effective insulation.
Preventing Seal Failure With Warm Edge Spacers
As the weather changes from summer to winter and back again, expansion and contraction within the window unit can happen. Over time, this can lead to seal failure and major insulation issues if not addressed. Warm edge spacers present an effective solution to this potential seal failure.
Warm edge spacers insulate the edges of the window unit and keep the glass panes firmly apart from each other. These spacers add structural stability and mitigate the stress that comes with thermal expansion and contraction in different weather conditions. By expanding and contracting at the same rate as the insulated glass unit, they help to prevent any gas from escaping and the window’s seal from failing.
3. The Best Windows For Colder Weather Will Take Advantage of Natural Light & Heat
Both the natural light and heat from the sun are in a shorter supply during the winter months. As a result, it helps to have windows that help you take maximum advantage of both. Let’s start by looking at natural light.
Don’t Let Your Windows Cut Off Your Natural Light
Visible Transmittance (VT) is the metric that determines how well a window permits the flow of natural light into a home. By allowing more natural light, a window helps reduce the need for artificial light sources. VT is one of the main factors used by third-party organizations like the National Fenestration Rating Council (NFRC) and Energy Star to assess windows and assign an overall rating for energy efficiency.
There are many factors that can prevent your windows from maximizing the natural light transmittance during the winter months, including:
Triple-Glazed Windows: Refers to a window with three panes of glass within the frame. While they can improve other energy efficiency metrics such as U-Factor, triple-glazed windows do create more tint which will impede visible transmittance and result in less natural light.
Big, Bulky Frames: A typical mullion (what separates panels of glass in multi-sash windows such as double or triple casements) for hollow vinyl PVC frames is usually six inches wide. This means less glass surface area through which light can enter the home.
Fixed Insect Screens: Fixed, immovable insect screens collect dirt, dust, and allergens over time. They can also block up to 50% of the natural light that flows into your home.
The best window for cold weather will offer solutions to these common problems:
- Custom-formulated windows can ensure that your window glass suits your home’s unique needs and preferences — from glass types and glazings to gas fills and coatings.
- Because of their increased strength, steel- and aluminum-reinforced vinyl frames are a full three inches thinner than standard vinyl window frames. This means more glass surface area and more natural light transmittance.
- Retractable insect screens and blinds disappear when they are not needed, leading to more natural light transmittance.
The Right Windows Will Help You Use Solar Heat Effectively
When talking about the sun’s heat in relation to your windows, it’s important to understand the Solar Heat Gain Coefficient (SHGC). Another key energy efficiency metric, SHGC is one that measures how much solar heat enters a home via a window.
A key thing to understand about the SHGC is that the ideal number largely depends on where the home is located. A lower SHGC is great for hot climates exposed to lots of sunlight; a higher SHGC can be beneficial for colder, northern climates who want to take advantage of as much radiant heat from the sun as possible. Put simply, a lower SHGC can reduce cooling costs, while a higher SHGC can reduce heating costs.
To regulate and control SHGC, window manufacturers will place a very thin, transparent coating on the window’s glass called Low-E Coating. There are a variety of different types of Low-E coating formulations that are possible. The right formulation has everything to do with where the home is located. In Southern Ontario, where the weather changes drastically from hot to cold over the year, a balanced Low-E formula such as the ClimaGuard 70/36 is best. It’s designed to allow you to take advantage of the sun’s heat in the winter, while not having it be overwhelming in the summer months.
The Magic™ Difference: Because we manufacture and formulate our own glass packages, we will always work to provide you with a Low-E coating formulation that will work best for your home in both the summer and the winter.
Looking for Windows That Will Deliver Year-Round? Reach Out Today!
As important as it is to find a window that will perform at a high level in colder months, it’s even more important for homeowners in Southern Ontario to install windows that will perform well year-round and for years to come. After over 40 years of experience installing windows in Southern Ontario, we know what it takes to manufacture and install beautiful, energy-efficient, high-performance windows that deliver year after year, no matter the season.
Ready to transform your home? Book a free, no-hassle consultation today!