Glass Roof U Value

This glass specification will produce a glass unit with ug value of 1 0 1 1 w m 2 k.

Glass roof u value.

Reference table for u values u value is the coefficient of transmission i e the transmission of heat through the materials which compose the building s envelope or outer shell. So for example if the temperature difference on a typical cold day was 15 degrees then the amount of heat loss would be 15x6 90 watts per square metre. U value has an inverse relationship to r value. All insulated glass from iq is specified to this standard as a minimum.

There are various ways of improving the uw value of an installation. In descending order these are typical u values for glass. Double glazing with 16 20mm gap 3 0. The u value of a single sheet of glass as found in a traditional window pane is 6 0w m 2 k which means that for every degree of temperature difference between the outside and the inside a square metre of the glazing would lose 6 watts.

Triple glazing with 16 20mm gap 2 2. Determine the thickness of the insulation layer above the joists required to achieve a u value of 0 20 w m2k for the roof construction shown below. Technically u values are calculated as the amount of heat lost through one square meter of glass for every degree difference in temperature either side of the glass. Obviously improving the individual u factors in the calculation will improve the overall thermal performance.

You can expect a standard double glazed panel to have a u value of around 3 w m2k whilst a triple glazed panel with xenon filled cavities and low e coatings will have a u value of around 0 4 w m2k.