| Performance Page 3 |
Glossary of high performance glazing terms
 Bay window with copper awning |
- U Value
- The rate of heat flow through a glazing system; the lower the value, the better the insulating quality. U value can be compared to R value by dividing 1 by the U value. Thus, a U value of 0.5 equals an R value of 2.
- Low "E"
- Low emissivity glass is coated with a microscopically thin metallic layer that allows short wave light to pass through by reflecting long wave heat energy.
- Daylight transmittance
- Measures the amount of visible light that is transmitted through the glass.
- UV block
- Measures the amount of damaging ultraviolet light that is blocked from being transmitted through the glass. CertainTeed vinyl replacement windows have a thermal rating of 85% (85% of UV is blocked).
- Shading coefficient
- Measures how much glazing material transmits heat gain compared to 1/8" glass, which is given a value of 1. Thermaflect's rating of 0.51 means that Thermaflect reduces unwanted radiation by 49%.
Weather Resistance
- Factory sealed frames and fusion welded sashes: create a structurally strong unit that resists weather.
- Integral glazing system: bonds glass to sash, creating a weatherproof seal.
- Leak resistance: meets industry standards for water performance requirements for residential windows - i.e., no leakage.
- Air infiltration: exceeds industry standard thermal window specifications as much as six times - depending upon vinyl replacement window style.
- Drainage: sloped sill designs for double hung, casement, and awning windows; engineered weep systems for gliders.
Security and ease of use
 A 30 degree window brings you closer to the outdoors. A central fixed window flanked by casements offers excellent sight lines |
- Cam type lock and keeper: propriety design of locks pulls sashes tight for a weatherproof seal and makes it virtually impossible to open the windows from outside.CertainTeed vinyl replacement windows meet the requirements of CAWN 301-90 forced entry resistance test.
- Night vent: provides added security while allowing ventilation.
- Constant force balance system: For easy opening of double hung windows. This unique stainless steel balance system won't fail of corrode - tested to 10,000 cycles.
- Safe and simple cleaning: with easy release of the tilt latches, double hung window sashes lift out, and casement windows are specially hinged for easy access to the outside surface.
- High quality hardware: Visible hardware is made of a proprietary blend of UV stabilized engineering plastic, color matched to vinyl profiles. Fasteners, screws, and accessories are high quality stainless steel, PVC, and engineered plastics.
- Meets or exceeds standard building code requirements: Tested in compliance with A.S.T.M. fire and smoke test procedures. A.S.T.M. E-84: Flame spread-15 fuel contribution-0; smoke density-330. A.S.T.M. D1929: Minimum self ignition temperature 979 degrees F. A.S.T.M. D635: Average time of burning = 5 seconds; average length of burning = 10 mm.
