The technology of high-performance windows may be impressive, but the benefits are equally compelling. And these benefits extend beyond the more obvious ones.

Savings in Heating Costs

First and foremost, high performance windows are energy-efficient. They offer immediate savings on home heating costs. Depending on the house design and the existing levels of efficiency in the rest of the building, switching to high-performance windows  should yield 9 to 18 percent reductions in space heating costs.

Savings in Cooling Costs

Concerns about energy efficiency are not limited just to the heating season. In many parts of Canada, summertime heat requires space cooling. High-performance windows work equally well at keeping the heat out in the summer months. The same low-E coating that keeps infrared (heat) energy inside the home in the winter keeps unwanted heat out in the summer. This keeps the interior cooler and cuts down on the need for air conditioning. Studies have shown that, for most of Canada, it is still appropriate to choose your windows on the basis of the ER number. Exceptions to this rule are those few locations where air conditioning costs are high relative to the amount spent on space heating. In these few cases, consider west-facing windows with a lower solar heat gain potential.

Increased Comfort

In houses with conventional windows, air leakage, drafts and radiate heat loss all contribute to occupant discomfort which the heating system must try – usually with only limited success – to overcome. But high-performance windows are better insulated and maintain a much higher surface temperature on the interior glazing. This characteristic, together with effective weatherstripping and proper installation, makes the window “feel” warmer to the occupant. The heavy gas fills in high-performance windows, which reduce conductive and convective heat losses, also reduce sound transmission from the exterior to the interior. The greater the number of panes, the better the sound absorption. Sound attenuation is complex, depending on frequencies and other factors; some benefit may be realized with high-performance windows.

More Daylight

The advent of high-performance windows is allowing larger glazing areas to be incorporated into house designs, in both new construction and renovations, without the penalty of either high heat loss in the winter or high heat gains during the summer. This not only enhances energy efficiency and improves the view, but it also lets in more daylight, which may lead to reductions in the use of electric lighting. You save twice when you take advantage of this natural light: first, you save on electricity used for lighting; second, because a conventional light bulb uses only 15 percent of its energy for lighting and wastes the other 85 percent as heat, you lower the home’s cooling load in summer. This is especially the case in larger buildings.