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Windows
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French Doors
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Patio Doors
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Front Doors
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Roller Shutters
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Window Sills
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Windows
French Doors
Patio Doors
Front Doors
Roller Shutters
Window Sills
The u-value, also known as the heat transfer co-efficient, is a measure of the amount of heat lost through the product over a given time period. The lower the value, the more insulating and energy-efficient the product. The u-values given below (Uw for the window, Ug for the glass, and Uf for the frame) refer to those of a test window with a single sash, 1,230 mm in width and 1,480 mm in height.
| Glass Ug value W/(m²k) | Frame Uf value W/(m²k) | Window Uw value insulating glass edge seal aluminium W/(m²k) | Window Uw value insulating glass edge seal KSD W/(m²k) | Window Uw value insulating glass edge seal Swisspacer Ultimate W/(m²k) |
|---|---|---|---|---|
| 1.1 | 1.9 | 1.5 (1.54) | - | 1.4 (1.45) |
| 1.0 | 1.9 | 1.5 (1.48) | - | 1.4 (1.38) |
| 0.7 | 1.9 | 1.3 (1.28) | - | 1.2 (1.19) |
| 0.6 | 1.9 | 1.2 (1.22) | - | 1.1 (1.12) |
MB-70 – profile section
| Glass Ug value W/(m²k) | Frame Uf value W/(m²k) | Window Uw value insulating glass edge seal aluminium W/(m²k) | Window Uw value insulating glass edge seal KSD W/(m²k) | Window Uw value insulating glass edge seal Swisspacer Ultimate W/(m²k) |
|---|---|---|---|---|
| 1.1 | 1.8 | 1.5 (1.46) | - | 1.4 (1.37) |
| 1.0 | 1.8 | 1.4 (1.40) | - | 1.3 (1.30) |
| 0.7 | 1.8 | 1.2 (1.20) | - | 1.1 (1.11) |
| 0.6 | 1.8 | 1.1 (1.14) | - | 1.0 (1.04) |
MB-70 HI – profile section
| Glass Ug value W/(m²k) | Frame Uf value W/(m²k) | Window Uw value insulating glass edge seal aluminium W/(m²k) | Window Uw value insulating glass edge seal KSD W/(m²k) | Window Uw value insulating glass edge seal Swisspacer Ultimate W/(m²k) |
|---|---|---|---|---|
| 1.1 | 1.4 | 1.4 (1.41) | - | 1.3 (1.31) |
| 1.0 | 1.4 | 1.3 (1.34) | - | 1.2 (1.25) |
| 0.7 | 1.4 | 1.1 (1.14) | - | 1.0 (1.05) |
| 0.6 | 1.4 | 1.1 (1.08) | - | 1.0 (0.98) |
MB-86 – profile section
| Glass Ug value W/(m²k) | Frame Uf value W/(m²k) | Window Uw value insulating glass edge seal aluminium W/(m²k) | Window Uw value insulating glass edge seal KSD W/(m²k) | Window Uw value insulating glass edge seal Swisspacer Ultimate W/(m²k) |
|---|---|---|---|---|
| 1,1 | 7,0 | 2,3 | 2,3 | 2,3 |
| 1,0 | 7,0 | 2,2 | 2,2 | 2,2 |
AWS 50.NI – profile section
| Glass Ug value W/(m²k) | Frame Uf value W/(m²k) | Window Uw value insulating glass edge seal aluminium W/(m²k) | Window Uw value insulating glass edge seal KSD W/(m²k) | Window Uw value insulating glass edge seal Swisspacer Ultimate W/(m²k) |
|---|---|---|---|---|
| 1,1 | 1,7 | 1,6 (1,55) | 1,4 (1,43) | 1,4 (1,39) |
| 1,0 | 1,7 | 1,5 (1,49) | 1,4 (1,36) | 1,3 (1,33) |
| 0,7 | 1,7 | 1,3 (1,29) | 1,2 (1,16) | 1,1 (1,13) |
| 0,6 | 1,7 | 1,2 (1,22) | 1,1 (1,10) | 1,1 (1,06) |
| 0,5 | 1,7 | 1,1 (1,15) | 1,1 (1,10) | 1,0 (0,99) |
AWS 70.HI – profile section
| Glass Ug value W/(m²k) | Frame Uf value W/(m²k) | Window Uw value insulating glass edge seal aluminium W/(m²k) | Window Uw value insulating glass edge seal KSD W/(m²k) | Window Uw value insulating glass edge seal Swisspacer Ultimate W/(m²k) |
|---|---|---|---|---|
| 1,1 | 1,4 | 1,4 (1,43) | 1,3 (1,31) | 1,3 (1,26) |
| 1,0 | 1,4 | 1,4 (1,36) | 1,2 (1,24) | 1,2 (1,20) |
| 0,7 | 1,4 | 1,2 (1,16) | 1,0 (1,04) | 1,0 (1,00) |
| 0,6 | 1,4 | 1,1 (1,10) | 1,0 (0,97) | 0,9 (0,93) |
| 0,5 | 1,4 | 1,0 (1,03) | 0,9 (0,90) | 0,9 (0,86) |
AWS 75.SI+ – profile section
| Glass Ug value W/(m²k) | Frame Uf value W/(m²k) | Window Uw value insulating glass edge seal aluminium W/(m²k) | Window Uw value insulating glass edge seal KSD W/(m²k) | Window Uw value insulating glass edge seal Swisspacer Ultimate W/(m²k) |
|---|---|---|---|---|
| 1,1 | 1,1 | 1,4 (1,37) | 1,3 (1,25) | 1,2 (1,21) |
| 1,0 | 1,1 | 1,3 (1,30) | 1,2 (1,18) | 1,1 (1,14) |
| 0,7 | 1,1 | 1,1 (1,10) | 1,0 (0,98) | 0,9 (0,94) |
| 0,6 | 1,1 | 1,0 (1,04) | 0,9 (0,92) | 0,9 (0,88) |
| 0,5 | 1,1 | 1,0 (0,97) | 0,9 (0,85) | 0,8 (0,81) |
AWS 90.SI+ – profile section
When it comes to aluminium windows, the Uw-values are calculated using the individual U-values of the window frame, the glazing, and the heat loss experienced at the edge of the glass itself. For the sake of comparison, a standard window size of 1230 x 1480 mm is usually used for the calculation.
The thermal insulation can be improved by adding a thermally separated edge seal to insulating glass known as a "warm edge spacer".
The heat transfer coefficient of an aluminium window or French door determines whether the product can be classified as being suitable for passive houses. Energy savings not only protect the environment, they also make an immediate difference to energy bills.
The difference between a Uw value of 3.5 W/m²K and 0.83 W/m²K can make a difference of more than 1000 litres of heating oil per year for an area of 30 m².