In a standard insulating glass sealed unit which comprises two sheets of ordinary glass, heat from a warm room in your home will be absorbed by the inner sheet of glass and radiated, or emitted, to the outer (colder) sheet, from which it is lost to the atmosphere. Unless this cycle is stopped, heat from inside the house will continue to be lost to the outside world through the two sheets of inefficient glass.
A sealed unit with low e glass, such as Pilkington K™ Glass or Planitherm™ has a low-emissivity coating (a virtually invisible metal or metal oxide layer) bonded to the surface of the glass facing the inside of the sealed unit.
This low-emissivity coating suppresses the radiation of heat from the warm inner pane of glass to the cold outer one, allowing some of the otherwise lost heat to be reflected back into the house. In this way a sealed unit fitted with low e glass is much more efficient at retaining heat in your home than one without.
In addition, light and heat from the sun travels through the outer, ordinary sheet of glass and hits the low e coating on the inner sheet, though some is lost back to the outer sheet, some of the energy is absorbed by the coating and radiated into the house. This bonus heat from the sun, known as solar heat gain, helps to make low emissity glass even more efficient at keeping your house warm.
As to be expected, there are different types of low e glass, referred to as having either a hard coating or a soft coating and some more efficient than others. Just a Quote can advise you which one is right for your home.
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