Window Energy Efficiency

Folk Windows Limited 10211 Keele St #231, Maple, ON L6A 4R7 Tel/Fax (905) 417-1585

Double and Triple Pane

Glass panes are the largest area of any window and the most vulnerable to heat loss and gain. To provide adequate thermo-insulation for harsh prairie climates, a minimum of 2 panes are required. Traditional 7/8″ double glazing options are used and can accommodate 1-1/4″ for all sliders and hung windows.

In areas with prolonged low winter temperatures, triple pane windows can be especially beneficial. Ecoline triple glass packages qualify for high energy-rating standards with 1-3/8″ and 1-1/4″ options available. Can be used in combination with gas injection and/or LoE glass coatings but are not necessary.

Find out more benefits of triple pane windows over double pane…

What Are the Criteria for ENERGY STAR Certification?

The following technical specification determines how residential windows, doors, and skylights sold in Canada are certified for the ENERGY STAR® program. This specification is issued by Natural Resources Canada (NRCan). NRCan has been authorized by the U.S. Environmental Protection Agency (EPA) to promote and administer the ENERGY STAR name and symbol in Canada. A product must meet this specification in order to be promoted as ENERGY STAR certified in Canada.
Energy efficiency requirements for windows and doors are reflected in Table 1 and Table 2 below.

Using ENERGY STAR certified products is an easy way to select energy efficient windows. To take advantage of passive solar gains, new specifications for the ENERGY STAR in the Fall of 2010 will ensure a minimum SHGC of about 0.22 and U-value of 2.0.

Table 1: U-factor Criteria for Residential Windows and Doors

ProductMax U-factor (W/m2·K)Max U-factor (Btu/h·ft2°F)
Windows and Doors1.220.21

Table 2: Alternate ER Criteria for Residential Windows and Doors

ProductMin ER (unitless)
Windows and Doors34

LoE Coated Glass

Low-emissive glass coatings help retain more interior heat than ordinary glass in cold winter months (Energy-gain) while filtering our harmful UV rays and reducing solar heat gain (Sun shield) in warm summer months. Multiple combinations of LoE glass coatings are available to achieve various levels of performance.

Argon and Krypton Gas

Argon and Krypton gases conduct up to 50% less heat than air. Using these gases to fill the spaces between double and triple pane windows protect against heat loss, condensation and cold weather for increased energy cost savings and overall comfort.

Up to 10% Thicker PVC Profile Walls

Ecoline incorporates 7% to 10% thicker PVC profile walls than industry average for all awning, casement, casement fixed and picture windows. They are also engineering to comply with heavier, large windows and triple-glazed glasses.

True Multi-Chamber Design

To improve structural performance and sound insulation plus reduced warping, all Ecoline window styles utilize a true multi-chamber design.

Multiple Glazing Options

A variety of glazing options are available for the best possible structural integrity. Traditional double glazing has a 7/8″ overall thickness (OT.) Triple glazing options are 1-3/8″ for awning, casement, casement fixed and picture windows. All triple glazing options for sliders and hung windows are 1-1/4″ with no grill limitations.

Screen Groove Port Design

Casement and awning windows now incorporate a new screen groove port design for improved push-down screen fit.

We guarantee the provision of products of the highest quality. Send us your messages, ask questions, our specialists will immediately contact you to clarify the details of your requirements.


1 thought on “Window Energy Efficiency”

  1. Stephen Thwaites

    High SHGC Underrated
    A high SHGC is the underrated window characterisitic for northern housing. Here’s an example to drive the point home.

    Consider a north facing window in Toronto. (Toronto is warm by Canadian standards, but fairly typical for the Northern US). Whether it has a low or high SHGC glazing the north facing window is a net energy loser. However, it is more of a net energy loser if it has the better insulating low solar gain low-e, than if it has the poorer insulating high solar gain low-e. So even on the north where there is no direct sunshine, there is enough diffuse solar energy to play a very significant role in the energy balance of a window.

    To be fair the difference between the two options for a north facing window is on the order of 1-2 kWh/ft^2 – so even if you heated with electricity, the difference in cost is on the order of $.10-.20/ft^2 of north facing window area over a northern house’s 200 or so day heating season. Not alot of money.

    Nevertheless the counterintuitive near parity of the two glazing options for a north facing window points to the underratedness of the SHGC.

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