Low-E glass has a microscopically thin, transparent layer that reflects long-wave infrared energy and is much thinner than a human hair (or heat).
Short-wave solar infrared light is reflected by several low-e materials.
During the winter, when the inside heat energy tries to escape to the colder outside, the low-e coating reflects the heat back to the inside, decreasing radiant heat loss through the glass.
During the summer, the opposite occurs.
Low-e glass functions similarly to a thermos, to offer a simplified illustration.
The silver lining of a thermos reflects the temperature of the beverage within.
Because of the continual reflection that happens, as well as the insulating benefits that the air space provides between the inner and outer shells of the thermos, similar to double glazing, the temperature is maintained.
When compared to standard glass, low-e glass can reduce the amount of heat that is conducted through the glass by roughly 30%.
Low-e glass enhances thermal efficiency even more by reducing glare and preventing ultra-violet ray damage to interior furnishings.
In recent years, low-e coatings have are commonl combined with laminated and toned glass to further enhance it’s benefits over ordinary glass.
Combining a low-e coating with double glazing provides the most comprehensive solution.
When compared to normal 3mm glass, low-e coating with a proper frame can limit up to 70% of heat leakage and 77 percent of heat gain.
The main downside of low-e glass is that it is more expensive than regular glass.
Low-e glass will trap the heat radiating from things within on facades that are in direct sunshine, potentially leading to interior overheating.
Additionally, glass with a low-e coating is easily etched when it is touched by metal and the cleaning process is different from other types of glass which is traditionally cleaned with metal blades. Using the same process to clean low-e glass will permanently damage them.