What Are The Window Ratings You Should Know?

What Are The Window Ratings You Should Know (1)

Being a homeowner opens up a whole new world full of technical details you didn’t know you needed to learn.  In terms of window ratings, there is a range of things you need to know in order to choose the best options. Window ratings explore basic window measurements that allow you to pinpoint the right choice for your unique property.

Window Rating Benefits

Benefit 1 Of Window Ratings: Energy Efficiency

The first benefit of understanding window ratings is the ability to compare and contrast different options. This allows you to shop around for the best deal without compromising on quality. This is extremely applicable to energy efficiency.

Being able to read and comprehend window ratings means you’re free to assess the specific energy efficiency rate of certain window models. As you’re paying for energy use in your home, your windows should help you preserve as much as possible and keep bills low.

Benefit 2 Of Window Ratings: Natural Light

Window ratings include visible transmittance (VT.) This measures how effectively daylight can penetrate a window. A light and airy room is much easier to achieve with a basic understanding of window ratings. Windows with high VT ratings mean you won’t need to rely constantly on electricity, reducing your energy bill expenses.

Window Rating Benefits

Benefit 3 Of Window Ratings: Insulation Efficient

Whether you’re using your air conditioner in the summer or you’ve got your heating on full blast in the winter, your choice of windows will determine where this air goes. When using window ratings, you can keep an eye on the insulation efficiency to avoid – quite literally – blowing money out the window.

Benefit 4 Of Window Ratings: UV Radiation Blockage

Windows are responsible for blocking up to 99.9% of UV radiation, according to the Skin Cancer Foundation. However, the exact percentage will be defined by the specific windows you install.

Assessing how well your windows block UV radiation is critical for two core reasons:

  • Your health
  • Fabric and color fading

Window Rating Labels


The National Fenestration Rating Council

The National Fenestration Rating Council is responsible for window ratings. Using their updated website, you can leverage their Window Selection Tool. The online tool searches a large database to help you find the best and most energy-efficient windows for your home and location’s climate. All their products are certified in their directory and contain clear energy efficiency labels.

The U Factor In Window Ratings

The U Factor in window ratings refers to the efficiency of the window and how well it contains heat. You should look for a lower rating, as this means that less heat is less likely to escape and offers better insulation. The U Factor will range between 0.20 and 1.20.

Condensation Resistance In Window Ratings

This component is optional for manufacturers to include and highlight on NFRC ratings. The condensation resistance measurement will show homeowners how likely it is for windows to build up moisture and condensation that can result in mold, damaged woodwork, and faded coloring.

The Condensation Resistance rating ranges between 1 and 100. In this case, you’re looking for the higher level, as it refers to how resilient a window is to condensation. The vast majority of ENERGY STAR windows come with high Condensation Resistance window ratings.

Visible Transmittance (VT)

Another core component of window ratings is Visible Transmittance. If you’re looking for lots of natural light, make sure to pay close attention to this particular window rating. Visible Transmittance window ratings will range between 0 and 1. A higher VT level for more penetrative daylight.

Air Leakage

Air Leakage is a window rating that measures how much air comes in via your window. Measuring in cubic feet in terms of how much air can pass through per square foot of your window area every minute.

This will impact the temperature and quality of the air in your home. On top of this, poor air leakage window ratings can be expensive to maintain and aren’t energy efficient. The lower the number, the less air leakage.

Solar Heat Gain Coefficient

The Solar Heat Gain Coefficient (SHGC) is a window rating that measures how effectively a window repels heat from the sun. This window rating is especially important for properties in hotter climates and will determine how often you may need to use your A/C.

The SHGC window rating will range between 0 and 1, and the lower the window rating, the lower your cooling bills will be during the peak heat season.

Use Window Ratings To Purchase Windows

Understanding window ratings is important when comparing different options. Once you understand what each of the ratings means and how to measure them, you’re free to pick a window choice that works best for your budget, household, and unique requirements. Call Bell Brothers today with any window questions you may have.