Window Terminology Explained

Between U-values and Low-E glass, figuring out what different window terms mean can feel like learning a new language. At Sunrise Windows, we’re here to help you get familiar with some of the most common terminology so that you can make sense of all the different component descriptions, ratings, and other jargon you may come across as part of the process of shopping for replacement windows for your house.

Terminology for Elements of the Window Design

There are a lot of different components of house windows, some of which you’re probably familiar with and others that you’ve never heard of before. Most homeowners are familiar with the frame as the outer part that holds the window together and the window pane being the glass area. If you want to familiarize yourself with a few more of the terms, here’s some additional window part terminology you may hear:

• Frame – The framework that supports the window system
  • Sill – The horizontal base of the frame
  • Head – The horizontal top of the frame
  • Jambs – The vertical sides of the frame
• Sash – The part that holds the glass panes
  • Rail – The horizontal part of the sash
  • Sash lock – The locking mechanism for operable windows
• Pane – A sheet of glass in the window
  • Multi-pane – Windows that feature multiple layers of glass
  • Gas fill – An inert gas between panes of glass for insulation
  • Grille – The gridwork that can be used to decorate the glass
  • Low-E glass – A coating on the window glass that helps deflect heat and UV rays

There are plenty of additional window parts as well, and we could go on for quite some time. However, unless you’re starting your own window business or have an unusual fascination with windows, this is typically more than sufficient terminology for your needs.

Performance Terminology for Windows

Many of the performance features of replacement windows have their own specialized terminology as well. These terms typically refer to different ways of measuring energy efficiency, which you may find on the National Fenestration Rating Council (NFRC) label. Common performance terms include:

• U-factor – How well the window prevents heat transfer; a lower number is better
• Solar heat gain coefficient – How much heat is blocked from the sun; the better number depends on your climate
• Visible transmittance – How much light your window lets through; a lower number is better
• Air leakage – How much outside air can enter through your window; a lower number is better
• Condensation resistance – How well the window resists condensation inside the window; a higher number is better

Getting a general sense of the terminology used to describe replacement windows can help you compare your options more easily. However, you don’t have to become a window expert to begin shopping around and exploring your various options. Your local window dealer should be able to explain the benefits of their windows in plain language as well.

If you’re interested in learning more about the features and benefits of having replacement windows from Sunrise Windows installed at your home, contact us today for assistance in finding a local Sunrise dealer near you.