seeking comfort

As oil prices in America continue to increase and energy consumption skyrockets, there is a clear realization that it is wise to become more energy efficient. Yet, floor plans continue to trend toward higher ceilings, open spaces and lots of windows, making our homes a target for energy waste. Even though “green” thinking has become more than a passing catch phrase, the average American home still has stipulations: we want beauty and we want comfort.

While most Americans agree that the hovering prospect of an energy crisis is worth being cautious through better energy wise tactics at home, we still, as a nation, spend billions each year on keeping our indoor climates beautiful and comfortable. This creates a complex challenge for window designers who are realizing that while cost efficiency is important to homeowners, saving dollars doesn’t necessarily carry as much weight as comfort.

Heating, ventilating and air conditioning (HVAC) equipment cannot provide maximum comfort on its own. Even at adequate temperatures, discomfort may result from cold drafts, strong solar radiation, and variations in radiation temperatures when different body parts face window surfaces. Studies show that occupants tend to offset discomfort by adjusting thermostat settings which, in turn, increases cooling or heating loads. By gaining an understanding of the relationship between windows and comfort quotient, window designers can create better design solutions while reducing equipment costs and duct losses. Homeowners will benefit by having more options.

Window design for comfort can provide energy and non-energy benefits, but there are many selections. If you want to literally prevent throwing money out of your window, take note of some of the offerings that improve the thermal efficiency of glass panes. Then sleep well, knowing you’ll awaken to a sunlit home of ethereal views that is comfortable without costing you a fortune in energy loss.

One Pane or Two. The original window design consisted of a frame, a glass pane and a latch. For many years this sufficed until designers realized that two layers were better than one. Today windows that are considered energy-efficient require at least two layers of glass. These are known as double-glazed windows, and they insulate almost twice as well as single panes. A third or fourth layer can further improve efficiency, but at some point visibility becomes an issue.

In addition to heat loss, radiation transfer affects comfort. One way to curb ultraviolet rays is to install tintable layers of thin plastic film for the third and fourth glazing. Also look for products with ultra thin, low-emittance (Low-E) coatings of silver or metallic oxide that are applied to the inside surfaces of insulating glass. Low-E coatings permit visible light to pass through while reflecting ultraviolet rays, which can fade interior floor coverings and furnishings. Different low emittance (Low-E) coatings are available for different climate zones, so if this is an alternative you are considering, talk to your window supplier about your options.

The cost of double-glazed windows quickly pays for itself in the money you save from heating and air costs. After installing double-glazed windows heating costs should decrease by 10-12%. Additionally, these windows provide an environmentally friendly element as they reduce the amount of home carbon dioxide emissions. They also reduce noise pollution, dangerous internal condensation, and security breaches.

Air Space. Between the glass panes in a double-glazed window is an air space intended to help with insulation. Thickness ranges from 1/4” to 1”, and the thicker the space, the less transfer of heat. Spaces greater than 1” show no significant gain in performance.

Double-glazed windows are filled with air and flushed with dry nitrogen to make sure the unit is airtight. A drying agent is added to ensure no moisture is present. In an effort to improve this process, manufacturers are also filling the space with less conductive gases like argon, carbon dioxide, and krypton. These gases reduce the overall transfer of heat, or U-factor, by suppressing conduction and convection.

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Edge spacers. Edge spacers hold the panes of glass together and seal air within the insulated window. Traditionally, hollow aluminum channels filled with desiccant beads to deter moisture were used for these spacers. Since aluminum is highly conductive the system was found to cause heat loss, not through the window panes, but through the edges. New improvements for this problem include using thin-walled steel with thermal breaks or silicone foam. These materials reduce heat transfer at the edge of an insulating window.

If you love enjoying your lowcountry views of twisted oaks, rolling ocean waves, and professionally manicured golf courses from the comfort of your living room, don’t worry. You can keep it all and still be energy conscious. In the world today we are all learning to pay more attention to what’s going on around us. With advances in technology and so much attention on saving energy, there are always options when it comes to building your home.