GLOSSARY-A

AAMA

American Architectural Manufacturers Association. A national trade association that establishes voluntary standards for the window and door industry. [Link to AAMA site]

Air infiltration

The amount of air that passes between a window or door sash and its frame. It is measured in terms of cubic feet or air per minute, per square foot of area. The lower the number, the less air the unit lets pass through.

Aluminum

clad windows and doors - Windows or doors of wood construction covered on the exterior with extruded or roll-formed aluminum. Has a factory-applied finish to deter the elements. Angle bay window - See: Bay window.

Annealed glass

Annealing is a process of slowly cooling glass to relieve internal stresses after it was formed. Glass which has not been annealed is liable to crack or shatter when subjected to a relatively small temperature change or mechanical shock. Annealing glass is critical to its durability. If glass is not annealed, it will retain many of the thermal stresses caused by quenching and significantly decrease the overall strength of the glass.

Anodize

Anodizing, or Anodising in British English, is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. The process is called "anodizing" because the part to be treated forms the anode electrode of an electrical circuit. Anodizing increases corrosion resistance and wear- resistance, and provides better adhesion for paint primers and glues than bare metal.

Apron

Inside flat trim member which is used under the stool at the bottom of the window.

Arch top

A unit shaped like a tombstone, has a smooth curve where the head and jambs meet.

Argon

An odorless, colorless, tasteless, nontoxic gas that is six times denser than air. Replacing the air between two panes of glass with argon gas reduces temperature transfer, making the surface of the glass inside the house closer to the inside temperature.

Astragal

An interior or exterior molding attached to one of a pair of doors or side-hinged windows in order to prevent swing through; also used with sliding doors to ensure a tighter fit where the doors meet. Often found on older casements or swinging screens.

Awning window

Top-hinged sash. See: Jal-Awning window.