If you have looked into replacement glass, you have probably come across the term Low E. It stands for low emissivity, and it is one of the main reasons modern double glazing performs so much better than units made a few decades ago.
How it works
Low E glass has a microscopically thin coating, usually made from metal oxides, applied to one surface of the glass. You cannot see it in normal use.
Heat from radiators, people and everything else in a warm room travels towards the windows as long-wave infrared energy. The coating reflects much of that energy back into the room instead of letting it escape outside. Daylight, which is a different kind of energy, still passes through.
In a double glazed unit the coating sits on one of the faces inside the sealed cavity, where it is protected from cleaning and the weather.
What it means in your home
- Warmer rooms. More of the heat you pay for stays inside.
- A warmer inner pane. The glass on the room side does not feel as cold, so sitting near a window is more comfortable.
- Less condensation on the room side. Because the inner pane stays warmer, moisture is less likely to settle on it.
Hard coat and soft coat
There are two main ways of applying the coating. A hard coat is applied while the glass is being made and is very durable. A soft coat is applied afterwards, generally performs better, and is designed to be sealed inside a double glazed unit. Your installer will choose the right type for the unit.
Is it worth it?
If you are replacing a sealed unit anyway, energy efficient glass makes sense, and it comes as standard on our replacement units. It is especially worthwhile if your existing units are older, because the improvement over early double glazing can be noticeable.
It is worth thinking about other options at the same time. Conservatories may benefit from solar control glass, and units for doors need safety glass. Our glass we make page lists what we can supply.
If you would like to know which glass suits your windows, ask us for a free quote.
