A detailed Energy Star windows guide for those who want to double their home's energy efficiency

What does the Energy Star rating mean?

Energy Star is a revolutionary government-backed program designed to reduce environmental pollution and help homeowners cut their spending on electricity. According to this program, selected products like windows and doors are approved as the best ones for efficient energy consumption. If the product exhibits this label, you can expect it to help you save on energy bills by means of improved home insulation and heat exchange. 

Here are the primary purposes of the Energy Star label: 

• Optimize the amount of greenhouse gas emissions and other pollutants caused by mass usage of fossil fuels
• Boost the amount of energy-efficient windows on the market, mainly in the home improvement segment
• Make it easy for shoppers to identify the products that feature the highest energy-saving potential 

What is an Energy Star window?

Windows protect a house from the elements and keep a stable temperature inside, regardless of the season or regional climate. This is achieved by double or triple glazing with high thermal performance that prevents heated or cooled air from escaping the home. 

Window units go through countless tests to become Energy Star-certified. They must meet rigid energy efficiency guidelines set out by the U.S. Environmental Protection Agency. 

Here are some of the Energy Star window requirements set by EPA:

• A window should contribute a significant energy saving
• Efficient energy consumption can be achieved through technologies offered by window manufacturers
• Windows have to deliver the requirements demanded by consumers, including improved energy-saving properties 
• Shoppers should be able to recoup their initial investments through considerable utility cost savings, especially if the certified window costs more than a conventional alternative

What factors contribute to the energy efficiency of the window?

Factors contributing to the window's energy efficiency include frame material, glass type and how a window is installed. 

In order to possess a high energy-efficient rate, a window should come with double or triple panes made of Low-E glass and filled with inert gasses like argon or krypton. Insulated window glazing serves to lower the U-factor and solar heat gain coefficient. It protects your home from harmful sun rays in summer and prevents heat air from escaping the building through windows in winter. 

Frames with enhanced thermal resistance also contribute to the overall energy efficiency of a window. We recommend setting your sights on wood, vinyl, and fiberglass, as these are the best insulating materials that provide reliable thermal resistance, preventing air leakage. 

Installation is the last but not least factor making the difference in the energy-efficient window performance. If a unit is installed with mistakes, it won't serve as it should, resulting in you throwing your money down the drain. Consider hiring a professional contractor to ensure your new Energy Star-certified window is mounted with maximum accuracy. 

What are the most energy-efficient windows out there?

Not all windows are made the same. They come in different types and configurations while meeting different purposes, from aesthetic to energy-saving. If you're looking for an Energy Star window for your home, consider casement, double-hung and picture units, as their configuration promotes better insulation and longer service life. 

• Casement windows. These units can be installed in virtually any room of the home. They are functional and provide a perfect view while maximizing air circulation. Casements are also some of the most efficient windows in terms of insulation and thermoregulation. Their operational mechanism allows them to be shut tightly, preventing air leaks and ensuring reliable insulation. Fixed and double-glazing casement units are best to install in extreme climates. 
• Double-hung windows. Windows of this type are highly widespread around the country. They offer an excellent price-quality ratio, providing dependable insulation. They open without protruding either inwards or outwards, saving space in rooms of different sizes and purposes. While featuring excellent energy-saving characteristics, these windows are still inferior to their casement counterparts, as the latest show excellent insulation even in extreme climates.
• Picture windows. These units fall into the range of fixed ones, which means they cannot be opened for ventilation, serving only barrier and decorative functions. Picture windows come almost unframed, allowing you to enjoy an unobstructed view. High-end units of this type come with double glazing, argon filling, low-E coating, and other energy-saving features that make them one of the best in terms of insulation. 

What are the benefits of thermal windows?

Getting all windows replaced in the home is a big money-consuming project not every homeowner can afford. That is why a desire to keep window replacement costs low is clear. However, cheaper is far from always better, especially when it comes to new home windows. By buying the Energy Star windows, you make a long-term investment in the energy efficiency of your house, enjoying rewards in energy savings and added property value. 

Consider the following advantages of modern energy-efficient windows to understand whether they are worth paying $750 - $1.550 per unit: 

• Lower fossil fuels use. Windows with Energy Star certificates are made to protect the environment and lower the need for energy consumption. They help to make a positive environmental impact for every homeowner seeking to switch to a greener life. 
• Lower utility bills. With Energy Star windows in your home, you won't need to turn on your heating and cooling units to a maximum, using only a third of electricity and gas to control your home temperature. This is one of the major factors considered by homeowners upgrading to Energy Star-certified windows. 
• Tax credit. Another significant advantage of installing energy-efficient windows is that you can take full advantage of tax credits, local rebates, and other financial incentives issued by the government. By blending hearty financial incentives and utility savings, you can find your investment in new Energy Star windows recoup quite quickly. 
• Top insulation level. Windows approved by Energy Star are pretty effective at keeping cold air from getting inside the home. They provide maximum insulation, ensuring the interior of your home stays comfortable no matter the season or temperature. Thermal windows provide a reliable barrier to the home's interior, eliminating room hot and cold spots and keeping a stable temperature inside without much reliance on the HVAC system.
• Soundproofing. Another perk that comes with replacing old single-pane windows and updating them with double- or triple-glazing units approved by Energy Star is the ultimate reduction of outside noise. A barrier made of several insulated glass panes ensures maximum soundproofing even if the home is in a high-traffic area. 
• Home interior protection. You may be surprised, but a sufficient U-factor rating of ENERGY STAR window panes blocks harmful ultraviolet rays that are known to make floor coverings, wooden surfaces, and drapes fade. More than 98% of all UV rays coming through panes are blocked, allowing you to save on updating furniture and carpets.

What to know about Energy Star window ratings?

When you're in the market for Energy Star-qualified windows, consider window ratings like U-Factor and SHGC or Solar Heat Gain Coefficient. They show how well the window is insulated and how much solar heat it transfers. Look below to learn more about SHGC and U-Factor standards and pick the right window option based on your climate zone: 

• U-factor. This rate measures the insulation level of a window, door, or skylight, indicating how well it transmits non-solar heat flow. U-factor ranges from 0.20 to 1.20, with the lower one meaning better insulation and vice versa. 
• SHGC. The solar heat gain coefficient measures the amount of sun's heat that comes through the window. This heat is transmitted directly through panes or absorbed and released as heat inside a home. The SHGC indicator ranges from 0 to 1, with the lower one indicating that less solar heat comes through the window. The optimal solar heat gain coefficient for your new energy-saving window should be determined by the local climate, the home's orientation, and external shading. 

Look at the table below to understand which indicators of SHGC and U-factor meet your climate zone best.

What to look for when buying the Energy Star windows?

Assume you made up a decision to buy new energy-saving windows for your home. What is next? You either go for professional assistance to pick the right window or head to the store with a bunch of questions and concerns. As multiple window types and manufacturers are seen on the market, you may easily get overwhelmed with the choice. That means you should have precise information on what to look for to minimize the risk of a faulty purchase. 

The following tips will help to make a purchase with a cold head and pick an Energy Star window that is worth the investment: 

• Make sure the Energy Star label is placed on a unit. It serves as an indicator of the highest quality and energy efficiency. Besides, it shows the climate zones where that window will perform best.
• Pay attention to the local climate variabilities in selecting the required window's energy efficiency. The U-Factor and solar heat gain coefficient should come to the allowed range in your region. The Energy Star climate map is often placed on the product label.
• Select different window options depending on their placement in your home. Window orientation, including shading and facing the sun, pay a significant role in their performance. 
• Consult a shop assistant about the Energy Star window options that are eligible for the rebates and federal tax credits. Participating in the financial programs approved by the government in the energy sector will help you to defray part of the cost upfront.