Low emissivity (low e or low thermal emissivity) refers to a surface condition that emits low levels of radiant thermal (heat) energy. All materials absorb...

However, the most commonly used form of emissivity is the hemispherical total emissivity, which considers emissions as totaled over all wavelengths, directions...

A low-emission zone (LEZ) is a defined area where access by some polluting vehicles is restricted or deterred with the aim of improving air quality. This...

The Ultra Low Emission Zone (ULEZ) is an area in London, England, where an emissions standard based charge is applied to non-compliant road vehicles. Plans...

A low-emission vehicle is a motor vehicle that emits relatively low levels of motor vehicle emissions. The term may be used in a general sense, but in...

the glass with a low-emissivity (Low-E) coating, which reflects away much of the infrared light that hits it. There are two types of low-e coating. The...

An ultra-low-emission vehicle (ULEV) is a motor vehicle that emits extremely low levels of motor vehicle emissions compared to other vehicles. In some...

ultra-low emissions vehicle (SULEV) is a U.S. classification for passenger vehicle emissions. The classification is based on producing 90% fewer emissions than...

radiation (IR or radiant heat). To keep the sun's heat out of the house, a low-emissivity coating should be applied to the outside pane of glazed windows. If...

The ratio of any body's emission relative to that of a black body is the body's emissivity, so a black body has an emissivity of one. Absorptivity, reflectivity...