Carbon Saved by Installing Double Glazing
18% of heat loss in the home can occur through windows alone. Installing double-glazing can cut this by up to half, and save you around 10-15% off heating bills.
Double glazing is also safer, harder to break and cuts out noise.
According to the Energy Saving Trust, installing double glazing can save 740 kg CO2 a year.
How it Works
Double glazing, as the name implies, consists of two panes of glass separated by a heat-trapping air gap. The width of the gap should be between 16mm to 20mm. Greater gaps than this do not improve the insulating effect, unless the air is removed and the gap filled with another type of gas such as argon or krypton.
Windows can be classified by its U-value, a measure of the heat transfer through the window. The lower the U-value, the better the insulation properties of the window.
Normal sheet glass has a U-value of 5.4 W/m²K, typical double glazing has a value of half this at 2.8 W/m²K, and triple glazing brings the value down further to 2.1 W/m ²K.
Low-emissivity (low-e) coatings can reduce this number even more.
Like appliances, windows also have energy ratings from A - G
, and the most efficient will carry the Energy Saving Recommended logo.
Where to find double-glazing companies
Energy Saving Trust
http://www.energysavingtrust.org.uk/compare_and_buy_products/glazing
Double Glazing and Replacement Windows Suppliers Directory
http://www.double-glazing-replacement-windows.co.uk/
Fenestration Resource - searchable database of suppliers
http://www.fenestration-uk.com/Index.aspx
DoubleGlazing.com - directory searchable by location
http://www.doubleglazing.com/double_glazing_findasupp.htm
British Fenestration Rating Council (BFRC)
http://www.bfrc.org/defaultDirectories.aspx
Where to get further help and information
Energy Efficient Windows (US)
http://www.energy-efficient-windows.com/
Efficient Windows Collaborative (US)
http://www.efficientwindows.org/energystar.cfm
Windows Today
http://www.windowstoday.co.uk/
British Fenestration Rating Council (BFRC)
http://www.bfrc.org/
Energy Saving Trust
http://www.energysavingtrust.org.uk
