LET'S LOOK AT BOTH SIDES OF YOUR WINDOWS

Everyone knows how much windows can enhance a house. They add character and style. They let in sunlight and a view of the world outside. Windows also become part of the home's natural ventilation and they can add solar heat to the home. But windows can also be major losers of heat.

Conventional windows lose a large amount of heat each day, in a variety of ways. In fact, an average window can lose six to ten times as much heat as the same area of wall. That's why you often feel colder when you stand near a window.   That's also why the proper installation of energy efficient windows is such an excellent idea. It can save you money and energy, and make your home much more comfortable. Since new windows are a major investment, they should receive the same attention you'd give to other large purchases. This page is designed to help you make an educated choice, and also to inform you about the many new advances in window technology and the wide variety of options available.

REPLACING WINDOWS - IS IT NECESSARY?

The average window lasts at least 30 years. So replacing your windows, just to save energy isn't something that's usually recommended. For example, some heat & loss problems can be solved without replacing the entire window. You can improve the efficiency of your existing window by replacing old caulking, adding a storm window, adding shrink-wrap to the interior or by installing an acrylic inner sheet. However, if you are going to replace your windows because you also want to improve the comfort and looks of your home, or you want to reduce their maintenance and make them easier to clean, you should consider going the additional step of installing an energy efficient window. First, choose the features that are most important to you. Know what you want from your new windows. Then keep the benefits of energy efficient windows in mind:

Increased security

Greater personal comfort in the home (reduced drafts, increased warmth)

Reduced energy costs

Energy conservation

In addition, the payback period for recovering the incremental cost of newly installed energy efficient windows over buying standard windows can be as low as six years for homes with high heating bills.

Not at all.

Energy efficient windows are available in every conventional style as well as designer shapes such as octagonal, circular and semicircular. Energy efficient windows can also be designed to suit your personal taste and the style of your home, whether it's French, Georgian, Victorian or modern. Conventional rectangular windows come in several different styles, each with varying degrees of inherent energy efficiency. The most energy efficient are fixed windows, simply because they don't open, so there are fewer opportunities for drafts to be created. Obviously, such windows aren't suited to all applications. So let's look at windows that do open.

There are five basic types: casement, awning, hoppers, horizontal and traditional double-hung or single-hung sliders.

ARE All WINDOWS CREATED EQUAL?

Absolutely not While at a casual glance one window may look pretty much like another, there can be huge differences. Let's look first at the similarities. An energy efficient window is usually made up of three components: the glazing, the frame, and the spacers. Glazing is the glass & the transparent part of the window. The frame holds the glazing in place and joins the window to the surrounding wall. Spacers are found only in sealed glazing units. They hold parallel panes of glass apart and create an air space.

Ultimately, the energy efficiency of any window depends on the degree of efficiency of these three main components.

TYPE OF FRAMES

Frames are particularly important since they can reduce the overall performance of the window. So it's crucial that you consider both the materials and the design used. There are several frame materials to choose from.

Aluminum

Thermal Break

Vinyl

Wood

Wood Clad

Unfortunately, many people choose contractors based on price alone. It's a good idea to remember that the old maxim, "You get what you pay for"' is all to often true.

As with any other job, make sure that the quote for the work is provided in writing and in detail. How long has the contractor been in business? Are they Fair Trades Approved? Can he provide referrals? Does he have a business license? What type of  warranty does he offer on the products and installation.

Properly installed energy efficient windows can save you money, energy and make your home more comfortable.

Energy efficient windows come in a variety of styles to suit your specific needs and taste.

Energy efficient windows are available in a variety of different materials ranging from high to low maintenance.

The incremental payback period can be as low as six years.

Energy efficiency is just as important in the installation as it is in the window itself

Investigate the reputation of your contractor.

Energy efficient windows. Clearly, you win all the way around.

WINDOW TERMINOLOGY

R (RSI) measures thermal resistance It is often used when measuring the performance of insulation, such as that put into walls and attics to indicate how much heat is kept within the house or how much cold is kept out.

U-VALUE is the total heat transfer through the window, due to conduction, convection and radiation.

EMISSIVITY is the ability of a surface to radiate heat. An example of a good radiator (i.e., high emissivity) is a black electric stove element. Conversely, shiny metal surfaces such as the aluminum foil used to insulate hot food has a low emissivity. Low-E coatings reduce the emissivity of the glass surface, which in turn reduces the radiative heat flow out of a building through the glazing.

AIR INFILTRATION is how much air would pass through a closed window from the exterior to the interior. It occurs at the edges of the window, by the frame, if the framing component is of poor quality.

SHADING COEFFICIENT is the amount of solar energy passing through a window compared to a 3mm double-strength window. This is important in calculating solar heat gain.

SOLAR HEAT GAIN is measured as the ratio of solar heat gained through the window to the amount striking the window.