Window Terminology: Window Terms Starting with "S"

Safety Glass

A strengthened or reinforced glass that is less subject to breakage or splintering.  Also called tempered glass.


The portion of a window that you open and close.


Woven mesh of metal, plastic, or fiberglass stretched over a window opening to permit air to pass through, but not insects.  Screens come standard with UniShield windows.


A compressible plastic material used to seal any opening or junction of two parts, such as between the glass and a vinyl sash, commonly made of silicone, butyl tape, or polysulfide.


The ledge on the front of the interior of the window

Single-Hung Window

A window consisting of two sashes of glass but only the bottom sash opens.  The top sash always stays stationary and cannot be opened for air flow

Sliding Glass Door

A door fitted with one or more panels that move on rollers horizontally on a track and/or in grooves.  Also called a patio door.

Sliding Window / Slider window

A window fitted with one or more sashes opening by sliding horizontally.

Solar Heat Gain Coefficient (SHGC)

The fraction of solar radiation admitted through a window or skylight, both directly transmitted, and absorbed and subsequently released inward. The solar heat gain coefficient has replaced the shading coefficient as the standard indicator of a window's shading ability. It is expressed as a number between 0 and 1. The lower a window's solar heat gain coefficient, the less solar heat it transmits, and the greater its shading ability. SHGC can be expressed in terms of the glass alone or can refer to the entire window assembly.

Super Spacer

Glass spacing system made of a structural foam that keeps the edge of the glass warmer.   The foam does not transmit heat or cold through the window, and it is flexible enough to move with the entire glass package allowing the seal to hold significantly longer than metal or aluminum spacers.


For more information on window terminology, and to get your free quote on replacement windows from Universal Windows Direct, MN contact us today