Improving your home’s energy efficiency is now more critical than ever due to the increasing threats of global warming. Many designers develop innovative and functional ways of incorporating efficiency into their designs – but perhaps the quickest way to promote this is through energy-efficient windows.
For many people, aesthetics is an essential factor in choosing window designs. Thankfully, you don’t have to sacrifice your personal design choice by going green, as there are now many efficient windows available. By choosing sustainable replacement windows, not only will you lower down your energy costs, but you can also become more environmentally responsible by being part of the green initiative.
Understanding the importance of efficient windows is the first step you can take to incorporate sustainability in your home. But before we elaborate on this further, you might be wondering – what exactly are energy-efficient windows and how are they different from your standard windows?
What Makes a Window Energy-Efficient?
The easiest way to identify energy-savings windows is when you see the ENERGY STAR® label. You can rely on the efficiency of these windows as they were specifically manufactured to meet a variety of standards and restrictions to earn the badge.
Some of these specific standards include:
- Energy Star Windows for Northern Climates – These windows cause heat generation by letting infrared light inside, so they trap warm air inside your home. These windows are double or triple-paned, and their low U-factor proves their insulating capabilities.
- Energy Star Windows for Southern Climates – These are windows that help prevent air leakage in your home. Their low U-factor also proves their insulation value, making them a highly efficient choice for warmer climates.
Aside from these features, the window material and type of glass used also distinguish efficient windows from their traditional counterparts.
- Energy-Efficient Window Frames
Manufacturers construct window frames from a variety of materials. The window’s level of thermal resistance varies depending on the material used. Thermal resistance pertains to the superficial level of heat that the window can transfer inside.
- Wood window frames provide an efficient insulation feature.
- Fiberglass frames offer similar insulation as wood.
- Multi-chambered vinyl frames reduce heat loss.
- Aluminum is cost-efficient and durable, but it has poor insulation qualities.
- Energy-Saving Glass
Many factors affect a window’s efficiency, such as the glass’s type, thickness, and style. Reducing the conductivity level of the mirror and allowing certain sun rays to enter your home can significantly impact the comfort of your property as well as reduce your energy costs. These components contribute to the overall efficiency of window glass:
- The number of window panes – Double-pane glass offers superior insulation than single-pane glass. Triple-pane glass, on the other hand, can boost energy savings.
- Glass coating – Any window glass tinted with Low-E (low-emissivity) coating can effectively reflect solar heat. Since it has many variations, Low-E glass will primarily depend on your location.
- Insulating gas – Many windows contain harmless gas that provides an extra layer of insulation that significantly improves thermal performance.
- Solar window film – Like Low-E coating, a solar window film adds more tint to your windows.
- Professional Window Installation
The construction of the materials used in the window is not the only factor affecting its efficiency – proper installation by a professional is also necessary. Even the most sustainable window can lose its energy-saving qualities if not installed correctly. Professional installation helps ensure your efficient window performs as expected. In addition, you can rely on window experts to consider your aesthetics by using seamless products, such as glass fiber reinforced cement.
One of the small changes to further enhance your window’s efficiency is adding a layer of insulation foam within the window frame during the installation stage. This process provides another layer of protection against air leakage, significantly boosting your window’s performance.
What to Look for When Choosing Energy-Efficient Windows
It would be best to look for labels in windows indicating their energy-efficient benefits for the highest energy-saving potential. Windows marked with ENERGY STAR® and NFRC labels have been meticulously tested to meet specific performance standards.
ENERGY STAR® is a government initiative from the U.S. Environmental Protection Agency (EPA) that provides sustainability options to businesses and individuals by certifying energy-efficient windows, doors, appliances, and other home products.
There are three factors involved in identifying an ENERGY STAR® certified window:
- U-Factor – indicates how easily heat flows through a window. The lower the U-factor, the more insulative the window will be.
- Solar Heat Gain Coefficient (SHGC) – measures the amount of heat-causing light that can travel into a home through the window. Lower numbers here signify that less solar heat is allowed in.
- Air leakage rating (AL) – measures the amount of air allowed through the frame and joints per square foot of window space. Windows with a lower AL rating allow less air to flow through.
The ENERGY STAR® label indicates whether a window is certified by the government and the specific location. Depending on your site, the label also tells you which energy performance rating to search.
NFRC Window Ratings
While the ENERGY STAR® label indicates that a window is up to energy efficiency standards, the National Fenestration Ratings Council (NFRC) rating indicates a more apparent manifestation of the window’s energy performance than other windows.
Similar to ENERGY STAR®, the NFRC label also includes two critical ratings:
- U-Factor – represents the heat rate that flows out of the window each hour. The lower the number, the better the unit insulates.
- Solar Heat Gain Coefficient (SHGC) – rating measures the amount of solar radiation that enters as heat.
NFRC window ratings are a definitive way to measure the whole unit’s energy performance. Window manufacturers align their products under NFRC standards to earn the status and use the label.
From design and features to energy-saving options and professional installation, purchasing sustainable windows can be a complex undertaking for many people. You can start by comparing efficient replacement windows, but every feature you add can change its energy rating. Hopefully, these guidelines can help you look for the most critical factors depending on your location and energy requirements.