The U value of a material is a measure of how well heat passes through the material and the lower the U value, the greater the resistance to heat and therefore has a better insulating value. The U value is normally found in the building and construction industry to specify assemblies or combintion of elements which provide an appropriate insulation and energy efficiency value. The U-Value unit of measurement is W/m2 and pertains to the volume of heat lost in watts (W) per square metre of material.
What is a Good U Value
The lower the u-value the lesser the heat loss, insulation is better and effectively provides for lower fuel bills. Be care ful when you are being quoted u values and always ask if the value applies to the full assembly or just one element of it, such as the glass.
Example U-Values in Kingsbridge Windows:
Timber Tilt and Turn Windows
Timber tilt & turn windows is our most energy efficient system. The 78mm profile with a 42mm triple glazed unit can achieve a U-Value of 1.0W/m2K, and water tightness of 1500Pa. A standard 68mm profile with a 32mm unit will achieve 1.5W/m2K.
The standard Low E, Argon filled double glazed units give U-Value of 1.4W/m2K. The same window when triple glazed reaches a value of about 1.2W/m2K and better depending on window design.
Warm edged 44mm Low E, Argon filled triple glazing units are used in the standard timber passive window to achieve a U-value of 0.83W/m2K. Modified Alu Clad version U-Value is 0.78W/m2K
Kingsbridge Joinery sash windows achieve U-Values of 1.5 W/m2k for the hardwood window and 1.4 W/m2k for the softwood or Accoya® window. For more on U Value Sash Windows