Anatomy of a Window: How the Parts of a Window Work
Some parts of a window are more prominent than others. Here's what you need to know.
Learning the parts of a window can help you better understand how to properly operate and clean it, and how to communicate trouble spots if your window needs maintenance or warranty service. Here we walk you through the four main components of a window, and several other window parts with everything you need to know.
4 Major Components of a Window
The connection between the spacer and the glass panes is called the seal. Super strong adhesive creates the window seal which is essential for keeping the window’s insulating gas between the panes of the IGU. Window seals usually deteriorate or fail after 5 to 7 years, causing fogging and reducing the effectiveness of an energy-efficient window. Look for a company like Improveit with a lifetime warranty that covers seal failures.
More About Glass
- Glazing – Refers to the glass components of a window.
- IGU – Insulated Glazing Unit. The IGU includes the window’s glass panes, the spacer, and the inert insulating glass between the panes. Together, this IGU assembly sits inside the window sash.
- Inert Gas – Most IGUs are filled with an inert gas, either argon or krypton, between the two panes of glass. Inert gases are denser than air, which prevents heat loss through the window glass, improving the window’s overall energy efficiency.
- Low-E – An abbreviation for Low-Emissivity. Low-E refers to a coating that is factory-applied to the glass panes. Low-E coatings improve a window’s energy efficiency by reflecting sunlight away from the window, and also help prevent UV rays from fading or damaging your interior finishes.
Anatomy of a window: Other essential parts of a window
Head – The top horizontal piece of the window frame.
Jambs – The vertical sides of the window frame.
Sill – The bottom horizontal piece of the window frame
Stiles – The vertical side pieces of the window sash.
Rails – The horizontal top and bottom pieces of the window sash.
Check Rail – On a double-hung window, the check rail is where the bottom rail of the top sash, and the top rail of the bottom sash meet across the middle of the window. This is usually where the sash lock is positioned.
Mullion – When multiple windows are combined into one unit, such as for a bay or bow window, mullions are the structural components that hold these windows together.
Screen – The woven mesh that covers a window opening. Window material is stretched across its own frame, which sits in a channel in the window sash. Window screens can often be removed or slid out of the way for cleaning. Window screens should never be considered a safety element. Refer to “safety stops” below to learn more.
Weep Hole – Small holes in the across the exterior side of the window sill from which rainwater is evacuated from the frame.
Lift – Running horizontally along the bottom rail of a double-hung window sash, the lift allows you to grip the window to open it. On a slider window, the “lift” will be positioned vertically.
Anatomy of a Window: Performax54 Special Features
Foam Insulation – Performax54 windows feature foam insulation that fills every nook and cranny of the window frame. This excellent insulation minimizes heat transfer through the window frame.
I-Beam Construction – Window frames must be structurally sound, so Performax54 window feature I-Beam construction that guarantees the frames won’t warp, bow, or sag, and helps the frame withstand expansion, contraction, and settling that happens with all homes.
SolarGold Spacers – The non-metallic SolarGold spacers in Performax54 windows are designed to seal out energy loss 72% better than standard spacers. The three hollow Air Cell Technology channels that run throughout SolarGold spacers are exclusive to Performax54 windows, and minimize warm-edge glass temperatures to reduce heat transfer.
Thermostat Glass – This smart glass technology in Performax54 windows works with the sun to maximize your energy efficiency. Strategic application of Low-E coatings reflect heat away from the window in the summer so your air conditioner doesn’t have to work overtime. In the winter, Thermostat glass allows low-angle sunlight to penetrate the glass, passively heating your home and reducing the heating load for your furnace.
Fusion-Welded Frames – While some windows are mechanically fastened with screws, Improveit’s Performax54 windows feature fusion-welded frames. This means the frames are assembled in the same manner as the steel frames from skyscrapers. Through the process of fusion welding, the welded seams on vinyl windows actually become stronger than the vinyl itself.
“Very, very pleased with the installation of windows. Service tech was very knowledgeable on his work and answered all my questions and concerns. He was very, very professional. His eye for details showed in his work.”
– Ken B., Louisville, KY
Window Accessories, Additional Terminology, and Other Parts of a Window
Crank Handle – Casement windows feature a crank handle for operation. Mounted on the frame, turning the crank handle opens and closes the vertical casement window sash.
Fixed Window – Inoperable windows, including picture windows and architectural windows, are often called “fixed” windows because they are fixed – not moveable – within their frames.
Grids – Window grids are decorative elements that give the appearance of dividing the window into smaller sections. Sometimes called “grilles” or “divided lites,” window grids are available in multiple patterns, including colonial, prairie, and diamond, to suit the style of your home.
Safety Stops – Safety stops provide an element of security when opening double-hung and slider windows. On double-hung windows, the safety stops are mounted on the stiles of the upper sash, approximately 4 inches above the check rail. When in the open or active position, the safety stops prevent the bottom sash from raising more than a few inches. This allows the window to be open for ventilation without creating a fall hazard from inside the home, or allowing unwanted access from the exterior of the house.
Sash Lock – All operable windows should have a sash lock mechanism that locks the sash inside the frame for security. On double-hung windows, the sash lock is mounted on the check rail, while casement windows have sash locks either on the top and bottom rails, or the vertical stile where the sash meets the frame.
Tilt Latch – On tilt-to-clean double-hung windows, two tilt latches are situated on either side of the top rail of each sash. Disengaging these latches releases the window sash from the frame to tilt in for easy cleaning.
Whether you’re just learning this window terminology or have a long history of home improvement expertise, Improveit is happy to discuss your window project and provide all the education you need. Reach out today for a free consultation.