Glass Roof U Value

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.

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. In descending order these are typical u values for glass. 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. Double glazing with 16 20mm gap 3 0.

All insulated glass from iq is specified to this standard as a minimum. For example a building with material with an r value of r 11 converts to an u value of 0 09 1 r or 1 11 0 09. There are various ways of improving the uw value of an installation. This glass specification will produce a glass unit with ug value of 1 0 1 1 w m 2 k.

Example of how u values work. 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. Triple glazing with 16 20mm gap 2 2. 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.

U value has an inverse relationship to r value.