Energy Efficiency

Every North Air window is a custom-built, high-performance product. It is critical that your windows are installed properly in order to enjoy all the benefits designed into your window.

Energy Star Program

The Energy Star program has become an international standard to help consumers save energy and money through the purchase of energy efficient products.

The international Energy Star symbol is a simple way for consumers to identify products that are among the most energy efficient on the market. Only manufacturers and retailers whose products meet the Energy Star criteria can label their products with this symbol. Choosing an Energy Star labeled product over a conventional model could save you hundreds of dollars in energy costs.


Because of the nature of Canada’s diverse climate, the country has been split into four zones to help you find the energy efficient products that best suit where you live. Zone A is the warmest climate, and Zone D is the coldest.

Once you’ve determined the zone where you live, you can find the best Energy Star-approved options available for your region. For greater energy saving, consider installing windows and doors suited for colder regions than your own.

For more information on Energy Star performance levels, visit the Canadian government’s Office of Energy Efficiency’s website.

Understanding key information will help you chose the right window for your needs. Sill to Sash: A Complete Guide to Windows and Doors from the Canadian Window and Door Manufacturers Association is a great resource for learning the basics about windows and doors. Below are some commonly used terms that are highlighted for you:

A window’s ER rating is a measure of its overall performance, based on three factors: 1) solar heat gain; 2) heat loss through frames, spacer and glass; and 3) air leakage heat loss. All window Energy Ratings (ER) are evaluated in the same way.

Is the number of panes of glass used in the construction of the window. The space between double- and triple-paned windows provides insulation. All windows should be at least double glazed with low-e to reach the energy efficiency and performance needed for the varied North American climate.

Refers to the balance between solar energy coming into and out of a home through the windows or building materials. The type of window glass and the placement of windows can contribute to heat loss and gain.

Low-E stands for low-emissivity. Emissivity is a measure of how much a glass surface transfers radiant heat.

When heating is needed, the key rating parameter is the U-value. The U-value describes how well a product prevents heat from escaping a home or building. U-value ratings generally fall between 0.2 and 1.2. The lower the U-value, the better a product is at keeping heat in. U-factor is particularly important during the winter heating season.

The R-value represents the resistance a material has to heat flow. It measures the effectiveness of insulation in stopping heat flow. The higher the R-value, the greater the heat resistance.

When cooling is needed, the key rating parameter is the SHGC. SHGC measures how well a product blocks heat from the sun. SHGC is expressed as a number between 0 and 1. The lower the SGHC, the better a product is at blocking unwanted heat gain. Blocking solar heat gain is particularly important during the summer.

The VT is the relative amount of visible light transmitted through a pane of glass. The VT ranges from 0 to 1. The smaller the VT, the less visible light is transmitted through the product. The higher the VT, the greater the potential for day lighting to offset the need for electric lighting.

CR measures how well a product resists the formation of condensation. CR is reported on a scale of 1 to 100. The higher the number, the better a product is at resisting condensation.