Oldcastle Glass Design Criteria Terms/Definitions

Absorptance: The ratio of radiant energy absorbed to total incident radiant energy in a glazing system.
Acoustics: The science of sound and sound control.
Adhesion: That property of a coating or sealant which measures its ability to stick or bond to the surface to which it is applied.
Air Infiltration: The amount of air leaking in and out of a building through cracks in walls, windows and doors.
Aluminum Spacer: Typically thin, hollow, aluminum tube used to contain desiccant (moisture-absorbing material) and separate the lites of glass in an insulating glass unit (see "Insulating Glass Unit").
Annealed Glass: another term for flat (float) glass that has not been further processed/fabricated; not a safety glass because it breaks into large, sharp pieces upon fracture.
Annealing: In the manufacturing of float glass, it is the process of controlled cooling done in a lehr to prevent residual stresses in the glass. Reannealing is the process of removing objectionable stresses in glass by reheating to a suitable temperature, followed by controlled cooling.
Antiwalk Blocks: Elastomeric blocks that limit lateral glass movement in the glazing channel that may result from thermal, seismic, wind load effects, building movement, and other forces that may apply.
Aspect Ratio: The quotient of the long side of a glazing lite over the short side of that lite.
Autoclave: A vessel that employs high pressure and heat. In the glass industry, it is used to produce a bond between glass and PVB or urethane sheet, creating a laminated glass product.