Heat Reflective Glass
Also known as Energy Efficient Glass, or low-e glass, heat reflective glass has a special metallic coating on one side. This very thin coating gives a slight brown or grey tint to the glass and allows the suns energy to pass through from the outside while reducing heat loss from inside the home. Heat reflective glass by itself does not improve insulation; it has to be part of a double or triple-glazed unit.
There are two types of heat reflective glass; the first is sputtered or soft-coat glass, this the coating is easily damaged by air or moisture, so it can only used on the inside of sealed double–glazed or triple-glazed units.
The second type is pyrolytic or hard-coat glass. Although this does not have to be sealed into a double–glazed unit, it is a less effective at keeping heat out of your conservatory in the summer.
Heat reflective glass will also reduce glare on really bright summer days, but still allow light into your conservatory on dull days.