Energy efficient windows are an important component of a well-constructed home. Windows utilized when building a new home need to be installed according to the code which has been established by state and local government regulation.
While the building codes address safety and structural durability, energy efficient windows can also be a green option which helps us to conserve energy and minimize utility costs. Here are some tips to choose the best energy efficient windows.
If you have an older home with windows installed prior to 1996, chances are that you will be needing an upgrade soon. Most Sarasota homeowners replace windows for energy efficiency, and as noted, will also gain higher levels of storm protection.
You may feel overwhelmed attempting to choose which windows are appropriate for your home. Shopping locally is a good idea to ensure that you get a window which is compliant with current codes. Working with a Sarasota or Longboat Key general contractor is a great way to gain the expertise – and choose the windows – which are best for your home.
As a rule, paying a bit more for the right windows will give your family the highest level of safety against hurricane force winds and flying debris, improve your home’s efficiency, minimize noise and UV light, and most likely reduce your home insurance premium.
Energy Star Windows
The most effective energy efficient windows meet ENERGY STAR standards as defined by the Department of Energy. These windows are rated by the National Fenestration Rating Council (NFRC) for energy efficient properties.
ENERGY STAR-compliant windows have a mixture of high R-values, low U-values, low E coatings, low SHGC (Solar Heat Gain Coefficients), high VT (Visible Transmittance), and AL (Air Leakage). These values are noted on a sticker affixed to each window.
- An R value measures resistance to heat.
- U factors measure the amount of heat transferred to the window material.
- Low E represents low emissivity. These windows have been treated with a metallic coating that reflects and radiates energy from heat.
- SHGC refers to the efficiency with which the window transmits solar radiation, as measured on a scale of 0 to 1. A “0” raying indicates that the window permits no solar energy to enter and a “1” rating means that it allows solar energy to enter.
- A VT value refers to the quantity of sunlight permitted through the window.
- The AL factor indicates how much air leakage is permitted to pass through the cracks in the frame.
Energy Efficient Impact Windows
Hurricane rated impact windows are constructed from impact-resistant laminated glass with special silicone glazing. This keeps them secure in their frames, even under stress. Double pane windows are made of glass bonded with polyvinylbutyral (PVB) and filled with argon gas, which provides the necessary insulating properties. This is a highly desirable attribute in the Sarasota area – you can sit near a sun-soaked window enjoying the rays while still feeling cool from your air conditioning. This is because the interior pane reflects room temperature and does not produce radiant heat. As temperatures increase throughout the summer months, having insulating glass saves you money on your utility bill.
In our South Florida climate, look for these values posted on the sticker:
U Factor – Lower than .6 is most effective. Definitely stay under .75
SHGC – .4 or below
VT Value – Between .3 and .8, depending on the amount of light desired
AL Value – Lower than .3
Many Florida residents choose “spectrally selective” windows, which exhibit a low SHGC and VT rating.If you are looking to renovate your home in order to make it more energy efficient, new windows are a great place to begin. Replacing windows requires a permit, so it may be in your best interest to hire a professional general contractor like Lindahl Construction for the project.