Fiberglass Replacement Window Terms
Argon and Krypton Gas
Used to fill the air space between panels of glass, this odorless and colorless gas acts to resist heat transfer through the insulating glass unit. It works within the low emissivity (low-E) coating on the glass to produce better U-Values. Krypton gas is another inert gas that is a more effective insulator; however it is more expensive.
Fenestration
How windows are arranged in terms of proportion and design.
Glazing
Window glass.
Double Glazing
When two panes of glass are set into a frame and are separated by an insulating air space. When This is referred to as Triple Glazing when three panes of glass are used.
Low-Emissivity Glass (Low-E Glass)
A coating on glass that reduces the amount of radiant heat and UV rays that passes through the glass.
Pultrusion
The way glass fibers and resins are joined together to form a window or door frame.
Single Hung
A window where only the bottom sash can be opened and closed. The top of the window cannot be moved.
Stile
The vertical parts of a window sash.
Transom
This is a window placed above a door or another window. It is usually smaller in size.
R-Value
Used to rate how well a material such as insulation resists the flow of heat through it. The higher an R-value is, the more heat loss it resists, and therefore the more energy efficient it is.
U-Value
A rating of energy efficiency. U-values rate how much the heat the window allows to pass through it.
Solar Heat Gain Coefficient (SHGC)
This is the rate at which heat is transferred (measured either by loss or gain) across the fiberglass window.