Glossary

A-E    F-S   S-Z 
 
Air infiltration 
See Air Leakage. 

Air Leakage (AL)
An NFRC rating. Amount of air flowing through a sash and frame. This NFRC rating indicates heat loss and gain through closures and joints in a window assembly. The lower the AL, the less air will pass through.

Awning window
Hinged at the top, opening outward.

Brickmold 
External casing around a window or door.

Casement window
Hinged at the sides, with sashes projecting out.

Chambers
Hollow sections designed into uPVC frames to provide added structural strength, insulation and noise reduction.

Cladding 
The exterior finish on a window or door.

Door panel 
Refers to the panels in a door. Active panels open and close, while inactive panels are stationary.

Double-hung 
Window style in which both sashes open and close; applies to both slider and hung windows.

Extrusion 
Process of forcing a substance through a specially designed opening or die. Our uPVC profiles are all extruded.

Frame 
The main supporting structure of a window or door. Made up of jambs, head jamb, and sill.

Glazing 
Process of sealing the glass to the sash. Also, the glass in a window or door.

Glazing bead 
A uPVC strip that keeps the glass in place on the door panel or window sash.

Grille 
Small bars that divide a windowpane for decorative reasons.

Hardware 
Handles, cranks, locks, tilt mechanisms, etc.

Head jamb 
The main horizontal piece that forms the top of a window or door frame. Also known as the head.

Hung window 
Window style in which sashes slide up and down.

Jamb 
The main vertical pieces that form the sides of a window or door frame.

Mullion 
the vertical or horizontal pieces that join single windows in a window grouping.

Pane
The sheet of glass in a door or window.

Picture window 
Window with no movable parts. Usually part of a window grouping.

 Sash 
The glass and frame assembly in a window.

Screen 
A removable framed mesh screen applied to windows and doors.

SHGC (Solar Heat Gain Coefficient) 
An NFRC rating. Measures how well a product blocks heat caused by sunlight. Ratings range between 0 and 1. The lower the SHGC, the less heat is transmitted indoors.

Sill 
The main horizontal piece that forms the bottom of a window or door design.

Single-hung 
Window style in which only one sash opens and closes; applies to both slider and hung windows.

Slider window 
Window style in which sashes slide horizontally.

Transom 
Small window above another window or door. Usually used for additional light and more rarely for ventilation.

U-factor 
An NRFC rating. Measures heat transmission or how much heat escapes through a product. Ratings usually range from 0.2 to 2.0. The lower the U factor, the more energy-efficient the door or window. Also known as U value.

uPVC 
Unplasticized polyvinyl chloride. The type of vinyl used in our windows and doors

Weatherstripping 
Material used to seal openings and small gaps in operating windows and doors to reduce air leakage and water infiltration.