Energy Efficiency Windows Guide
Are energy efficient windows worth the extra cost? The short and simple answer is YES. The real answer is depends, a lot of factors go into making your home more energy efficient, for example the placement of your building, exterior wall insulation, HVAC system and your appliances all play major roles in energy efficiency, placing energy efficient windows wont pick up the slack if all those things are not taken care of.Keep in mind that windows are responsible for 25%–30% of residential heating and cooling energy use so they do play a major role as well as the quality of installation. Poorly chosen windows can increase the cost of keeping a house cool, cause unwanted glare and reduce your overall comfort.
TERMS TO KNOW:
Solar Heat Gain (SHGC): Solar heat gain measures how well a product blocks heat caused by sunlight. It is the fraction of solar radiation admitted through a window and released inward. It is the most important performance factor in Florida when it comes to energy efficiency. A measurement of .30 or less is considered an energy efficient windows.
U-Factor: Measures the windows ability to prevent heat loss through conduction and convention and long wave infa-red radiation. The lower the rating the better the window is at preventing heat loss. Look for a U-factor at least as low as .65.
Air Leakage: Air Leakage is expressed as the equivalent cubic feet of air passing through a Square foot of window area. Heat loss and gain occur by air seeping through cracks in the window assembly. Look for a value of .3 cfm/sq. ft.
Visible Transmittance: Measure how much light passes through the product, do not confuse visible light with heat, Visible transmittance is an optical property.
Low-E: A film that is placed on the interior glass pane of a window to minimize the amount of infrared and ultraviolet light that comes through your glass, without minimizing the amount of light that enters your home. It is important to use a low-solar gain or spectrally selective low-e film in Florida not a high solar gain film that instead radiant heat back in doors similar to a greenhouse, these should not be used in Florida.
Argon Gas: Most windows double pane and triple paned windows have air space in-between each glazing but you have the option to fill with Argon Gas, Argon Gas insulates much better than air. Argon gas is non toxic and odor less.
High performance windows without a doubt are more expensive than basic counterparts but they are definitely an investment that will keep more money in your pocket in the future. Beyond the money saved on your electricity there are many incentives and rebates for having energy efficient windows in your home, ranging from various loans to rebates.
In conclusion, when shopping for energy efficient windows look for something that has a low SHGC (.30 or less), if you can afford a low-e film we reccomend it to all our customers that are looking to make they're home more energy efficient. Also make sure that the contractor installing your window is installing the windows per code and sealing the windows with high quality caulk.