Glass is a critical factor for top energy rating
Apart from construction materials and windows or door framing, the choice of glazing is probably the next most critical factor on the energy efficiency of a building. To ensure top energy ratings we pay particular attention to the quality of glass we specify for our windows.
A few words on glass and glazing options:
Conventional single glazing offers little resistance to the passage of heat. Solar radiation that is not reflected or absorbed is transmitted through the glass.
Tinted glass is the most common type of absorbent glass and comes in a range of colours.
Reflective glazing maximizes light transmission while reflecting solar radiation and is often used to reduce heat gain especially on western elevations.
Low E glass (low emissive) has a metallic or oxide coating which reduces transfer of heat or cold through the glass while still allowing light through. Mostly used in double or triple glazed units.
Double glazing (or triple glazing) consists of 2 or 3 panes of glass with sealed spaces of ideally 12 to 16mm in between. This space can be filled with air or an inert gas (like argon).
Argon gas has molecules that are larger than air molecules and can therefore provide better insulation properties, increasing efficiency by 7 to 15%. It is colorless, nonflammable and odorless and as such not detectable.
Triple glazing has 3 panes of glass (any glass combination can be used) with sealed spaces of ideally 12mm in between. Some triple glazed windows can have a u-value as low as 0.9
About U-Value
The insulation qualities of windows are measured in U-Value . The lower the U-value, the better the insulation properties of the window.
Single glazed 4mm glass U-value of approx. 6
Double-glazed 4mm glass, 6mm air gap U-value of approx. 4
Paarhammer Windows
Double-glazed 4mm glass, 16mm air gap U-value of 2.2
Different glass options (eg low E-glass. triple glazing) can bring the U-value down as low as 1.4. For exact values on varying glass options please contact Paarhammer. more >>>>