How New Windows Lower Your Energy Bills

Wondering how to keep your home nice and warm this winter season without causing your monthly energy bills to spike? It is a common concern for many homeowners, especially during this time of the year when we need our HVAC system to function properly to keep our interiors comfortable and cozy. Both the heat gain and heat loss that occur via our windows equate to around 25-30 percent of the heating and cooling energy use in residential homes. So, when it comes to keeping your home as energy efficient as possible, your windows play a major role.

Read on to learn more about how your current windows could be the problem and how new windows can lower your energy bills.

Designed to Reduce UV Rays

New windows today are generally manufactured using a Low-E coating, which is a thin, metallic coating. The “Low-E” represents low emissivity, which refers to how effectively the window can reflect heat instead of absorbing it. In essence, the glass prevents your interior from being impacted by the sunshine.

Window Glazing

The type of window glazing plays a significant role in the window’s U-factor or insulating properties. When we talk about glazing, we are referring to the type of glass – single, double or triple-pane – that’s used. Older windows in the past were typically designed as single-pane, which is why they are much more susceptible to temperature fluctuations. The more layers of glazing, the better your home will be insulated from what’s happening outside. This is why double and triple-paned glazing are frequently used today. They offer a superior shield for the glass and your home energy use.

Slow Heat Transfer with Gas-Filled Chambers

The chambers between the glass are also filled with Argon or Krypton gas nowadays. Aside from buffering out air leaks, these also help to reduce the intense glare and UV rays from the sun. Why does this matter? Aside from heating up your home, UV rays can also cause fading to artwork, rugs, furniture, and flooring. New windows prevent this from happening.

Protection Against the Winter Chill

If your windows are more than 30 years old, chances are they are not too comfortable to sit next to. Drafty windows that let cold air penetrate through will not only cool down the interior of your home, but it can also pull heat away from your body, causing you to feel that deep, winter chill even when inside. This is when many of us crank up the thermostat and throw on another layer. But as Canadians, we know how much it can add up when we are forced to blast the heat for several months during the year. Having ENERGY STAR® windows lets you curl up as close to the window as you wish so you can enjoy the view without having to blast the heat and use more energy.

Stay Cool in the Summer

No one wants to feel overheated and uncomfortable while at home. But our extreme seasons here in Canada can make that a reality every year, even in summer. During our intense heat waves, your old windows can attract approximately 75 percent of solar heat inside. Since ENERGY STAR® windows are designed to deflect that heat gain, you can enjoy the natural sunlight while staying cool throughout the summer.

Tips for Purchasing New Windows

When you are gearing up to replace your windows, remember some of these tips:

• Look for the ENERGY STAR® label to get the best energy efficiency rating for your home
• Make sure the windows are gas-filled for colder climates and have Low-E coating
• Generally speaking, for enhanced thermal resistance to maximize energy savings year-round, select windows with a low U-factor and low Solar Heat Gain (SHGCs). This, however, depends on your circumstances. For those with larger windows and increased sun exposure, values under 0.25 are recommended. On the other hand, those with smaller windows or overhangs who require more sun to warm up in the winter, a value above 0.4 is suggested.
• Talk to a window expert to get their advice on the best design and materials for your home and climate.

Aztech Doors and Windows offer high-quality products and services for all of your window and door related needs. Give us a call today to get started. 

Windows and Doors Energy Performance

The Canadian test standard for the energy performance of windows, doors and skylights is the CSA A440.2. Some products sold in Canada may also be tested to the United States standards of the National Fenestration Rating Council (NFRC) (100 and 200 standards). Tests are performed using standard sample sizes to fairly rank their overall structural and energy performance. Frequently, the energy efficiency ratings are derived by using computer software developed specifically for fenestration products.

Currently, testing the energy performance of factory-built windows, doors and skylights is mandatory in in Ontario, British Columbia and Nova Scotia.  Windows, doors and skylights in British Columbia and windows and sliding glass doors in Ontario – Hamilton, Guelph, Kitchener – Waterloo and area must meet a minimum efficiency standard.  The values that are most often used in Canada to represent the energy performance of windows, doors and skylights are the following.

U-value :- Indicates the rate of heat transfer from warm to cold areas in watts per square metre Kelvin (W/m2*K) or British thermal units per hour per square foot Fahrenheit (Btu/h*sq. ft.*°F).  The lower the value, the slower the rate of heat transfer.

R-value :- This value is the opposite of the U-factor and is not part of the energy performance standards.  It indicates the resistance to heat transfer in square feet per hour in Fahrenheit degrees of temperature per British thermal unit (sq. ft*h*°F/Btu). The higher the number, the higher the resistance to heat transfer.

Solar heat gain coefficient (SHGC) :- A ratio indicating the amount of the sun’s heat that can pass through the product (solar gain). The higher the number, the greater the solar gain.

Energy rating (ER) :- For windows and doors only, this unitless number reflects the balance between heat transfer (U-factor or U-value), solar gain and air leakage. Higher numbers indicate a slower heat transfer without significantly reducing the amount of solar gain.

Visible transmittance (VT) :- A ratio that indicates the amount of visible light that can pass through the product. The higher the number, the more visible light that can pass through.