Windows play a critical, but often overlooked role when it comes to building an energy-efficient home. There are many ways windows can reduce energy consumption and save you money. Well-placed windows can reduce energy use by decreasing your need to rely on artificial lighting throughout certain areas of your home. Additionally, well-sealed, high-performing windows will serve a critical role in keeping your home cool during hot summer weather.
Because windows have a major impact on utility costs, it’s important to work with your contractor to select the best options for your energy-efficient home. Before shopping for windows, it’s important to develop a good understanding of the various options on the market:
Measuring A Window’s Energy Efficiency
There are three important metrics to keep in mind when evaluating a window’s level of energy efficiency.
SHGC Rating – Also known as the “solar heat gain coefficient” rating, this number measures the amount of solar radiation that comes through a window. The rating is a decimal between 0 and 1. In warm Central Florida climates, you ultimately want less heat coming through the window in order to reduce the workload on your air conditioning unit. As a result, it’s best to integrate windows with lower SHGC ratings into your energy-efficient home when possible.
R-Value and U-Value – R-value and U-value are similar, but there are distinct differences. U-Value is used to measure the amount of energy that is transferred through the material, while R-Value specifically accounts for the material’s resistance to heat flow.
The lower the U-Value, the less energy is transferred through your windows. U-values range from 0.25 to 1.25. On the other hand, R-Values range from 0 to 5 (or even higher) and closely coordinate to the thickness of the glass. For example, an average single pane window will have an R-Value of around .90, while a double pane window will likely have an R-Value of 1.7 to 2.
Emissivity – Glass that can radiate energy is known to have a Low-E rating. In most cases, Low-E glass is double-paned and covered with a coating that is capable of transmitting light while reflecting heat. Low-E glass is always a great option when building an energy-efficient home in Central Florida.
Air Leakage – The amount of air your windows allow to escape also plays a significant role when it comes to energy-efficient homes. Air leakage is essentially the rate at which air moves through the space between the window and the wall. The typical way to measure air leakage is by calculating cubic feet of air that pass through one square foot of window area per minute. When building an energy-efficient home, your goal is to get the number as close to zero as possible.
The Best Window Frames For Energy Efficiency
Another important component of selecting windows for your energy-efficient home is the material of your window frame. Some window frames are more durable, while others have a greater impact on thermal performance. Below are some of the most common types of frame materials along with their advantages and disadvantages.
- Aluminum Frames – Aluminum frames are sturdy, light, and good-looking, but when it comes to insulation and performance, they’re not always the best option. Aluminum frames will likely decrease the U-Value of your window as metals are more likely to absorb heat. However, aluminum is recyclable, so the frames are environmentally friendly.
- Fiberglass Frames – Fiberglass window frames are strong, affordable, and energy-efficient. They have also become one of the most popular types of window frames over the last 10 years. Fiberglass frames are 60% recycled glass and are excellent insulators. As a result, most fiberglass frames are environmentally friendly, meet or exceed ENERGY STAR guidelines, and are great options for energy-efficient homes.
- Wood Frames
Wood frames provide excellent insulation by nature, but they generally require more maintenance than other materials. Without frequent conditioning, condensation can build up and cause the wood to rot, which may lead to a premature window replacement. Additionally, consistent expansion and contraction of the wood over time can lead to air leakage. However, as long as you’re willing to keep your frames in good condition, they should perform well in your energy-efficient home. - Vinyl (UPVC) Frames
Window frames constructed with unplasticized polyvinyl chloride (UPVC or Vinyl) perform very similarly to wood frames. While they can do an excellent job of preventing air leakage in the short term, they have a plastic consistency which means they’re more likely to see a decline in durability and appearance over time.
Windows Are Key To Energy Efficiency
Double-paned windows with high-performing frames are one of the best options for building an energy-efficient home in Central Florida. By keeping cool air trapped inside your home, you can reduce your air conditioning unit’s workload and ultimately decrease energy consumption during hot summer months. There are so many window options on the market today, so it’s important to work with a knowledgeable builder who can help you select the best windows for your energy-efficient home.
If you’re thinking about building a new energy-efficient home, contact us at Atlas Homes today. Our energy-efficient homes are affordable and comfortable, and our team of experts will work with you every step of the way.