Glass Roof U Value

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.

Glass roof u value.

All insulated glass from iq is specified to this standard as a minimum. 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. Example of how u values work. This glass specification will produce a glass unit with ug value of 1 0 1 1 w m 2 k.

U value has an inverse relationship to r value. Triple glazing with 16 20mm gap 2 2. 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. It is proposed to use mineral wool insulation between and over the joists with a thermal conductivity of 0 04 w m k.

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

Obviously improving the individual u factors in the calculation will improve the overall thermal performance.