Energy-saving, low-emissivity glass
En
Modern double-glazed windows are superior to conventional windows in almost all characteristics. This happens because their creators are working to improve every design element, including improving energy-saving characteristics.
It has been established that a significant proportion of heat loss during the heating season occurs through glass, so the desire to make them “warmer” is completely logical.
You can visually determine whether there is an energy-saving coating on the glass using a simple experiment. If the flame of a candle or lighter, reflected in the glass, gives a double reflection, one of which is yellow and the second slightly reddish, then there is a special film on the glass.
A little physics
To more accurately explain the concept of “energy-saving glass,” which is sometimes also called “low-e glass,” you need to brush up on your high school physics course. If we evaluate the ability of window glass to absorb (lose) heat on a scale from 0 to 1, then the value will be equal to 0.9 - this is the emissivity coefficient. Its physical meaning is that 90% of the heat will be given off, that is, window glass retains heat very poorly. Energy-saving glass has an emissivity coefficient of about 0.17, therefore, it cools 5.3 tenths times slower.To achieve this result, a thin layer, invisible to the human eye, is sprayed onto the surface of the glass, which significantly changes the ability to hold the glass. The energy-saving layer has important properties: retains long-wave heat rays indoors, maintaining indoor temperature; allows short-wave sunlight to enter the room, providing normal illumination.