What the U-Value of a Window Means

The u-factor, or u-value of a window describes how much heat passes between warm and cold areas. The score tells us how many watts transfer through a square metre of surface during a given period. However, for our purposes it’s sufficient to know the lower the score – or the more energy stars – the better.

The construction industry uses the same system to compare the insulation values of roof and wall materials. Having a low u-value means our heating bills come down because most of the warm air stays inside the house.

Who Decides the U-Value of a Window?

Windows, doors, and skylights made in Canada are tested against the Canadian Standards Association (CSA) A440.2 standard. However those windows made in the United States must comply with the National Fenestration Rating Council.

The following accredited agencies may award certifications in Canada:

CSA International

Intertek Testing Services

LabTest Certifications

Quality Auditing Institute Ltd.

The National Fenestration Rating Council

Some insulated glass units also bear the Insulated Glass Manufacturers Alliance mark. This then certifies the manufacturer can consistently build insulated units that will not fog and whose seals will not fail prematurely.

Choosing Windows Using Energy Star Ratings

The Energy Star system administered by Natural Resources Canada translates the u-value of a window into readily-understood stars. This makes it easier to single out quality products. These are the best energy performers that can pay for themselves through savings on our energy bills.

Most Energy Star products are in the top 15 to 30 percent of their class for energy performance. However it may not be necessary to go for highest rating depending on local climate conditions.

Correct Window Installation Enhances the U-Value

Always check for Energy Star certification before selecting hinged, sliding, fixed, non-openable, or tilt-turn windows. It’s important to ensure the seals are intact if deciding to do an installation yourself. That’s because the slightest gap can create a ‘wind tunnel’ through which the icy cold comes whistling through.

We don’t just install Energy Star-rated hinged, sliding, fixed, non-openable, and tilt-turn windows in Vancouver and surrounding areas. Silverline Exterior Solutions takes great pride in ensuring they are well sealed against the surrounding walls all round. The last thing you want is lying awake at night listening to the sound of whistling wind.

You can call Silverline Exterior Solutions at (604)-942-0488 for top-rate advice, or email us at any time. We are committed to providing five star service, every time you call.

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Preview Image: A Set of Fine Windows © Silverline Exterior Solutions