Thermal Conductivity is defined as a measure of the rate at which heat flows through a material. An insulating material is a poor conductor of energy and is used primarily to provide resistance to heat flow and therefore has a low thermal conductivity. The thermal transmittance of a material or an assembly is expressed as a U-value. The units of measurement are W/m²K. The better insulated a structure is, the lower the U-value will be. Thermal conductivity of PVC is 0.17 W/m2K and the thermal conductivity of aluminium is 160 W/m2K which means aluminium is almost 1,000 times more conductive than uPVC. In our thermal imaging you can see the thermal performance of existing typical single glazing aluminium window on the right, at best it has a U-value of around 6.5. On the left side you can see our uPVC double glazed window with U-value 1.7
Before photos of aluminium windows:
