Glossary of Window & Door Terms
Definitions for common industry terms, phrases, and concepts used in window and door manufacturing and selection.
- AAMA
- American Architectural Manufacturers Association — the source of performance standards, product certification and educational programs for the fenestration industry.
- Air Infiltration
- The amount of air that passes through a closed window or door. Measured in cubic feet per minute (CFM). Lower numbers are better.
- Argon Gas
- An inert gas used between panes of insulating glass to improve thermal performance and reduce sound transmission.
- Awning Window
- A window hinged at the top that swings outward at the bottom. Similar to a casement but mounted horizontally.
- Casement Window
- A window with a sash that swings outward on hinges. In strong winds, the sash presses inward against the frame for a tighter seal.
- Double Hung
- A window with two operating sashes, both of which can move up and down. Most popular style in the wood window industry.
- Eco-Ban
- DYC's antimicrobial weather stripping that resists air, mold, mildew, fungi, pollens, water, and dust.
- Emissivity (Low-E)
- A measure of a surface's ability to emit thermal radiation. Low-emissivity glass has a coating that reflects heat while allowing light to pass through.
- Glazing
- The glass component of a window or door, or the process of installing glass.
- Insulating Glass
- Two or more panes of glass separated by an air or gas space to reduce heat transfer.
- Interlock
- The overlapping meeting rails on a sliding window or door that help prevent air and water infiltration.
- Low-E Glass
- Glass with a microscopically thin metallic coating that reflects heat while allowing light to pass through. Significantly improves thermal performance.
- Mulling
- Joining two or more window or door units side by side.
- NFRC
- National Fenestration Rating Council — a non-profit organization that provides consistent energy ratings on window, door and skylight products.
- Picture Window
- A fixed window with no operating sash. Also called a fixed-lite window. Offers the best resistance to air and water infiltration.
- PolyPour
- DYC's proprietary thermal break process using high-density catalyzed polyurethane to separate interior and exterior metal surfaces in aluminum windows.
- R-Value
- A measure of thermal resistance. Higher numbers indicate better insulating performance. R-value is the reciprocal of U-factor.
- Single Hung
- A window with one operating sash that moves vertically while the other sash remains fixed.
- Thermal Break
- An insulating material placed between the interior and exterior metal components of an aluminum window to reduce heat transfer.
- U-Factor
- A measure of heat transfer through a window assembly. Lower numbers indicate better insulating performance.
- Weather Stripping
- A material applied around the perimeter of a window or door sash to seal gaps and prevent air and water infiltration.
