This coefficient is used to characterize the heat flow through a material or building element (wall, window, etc.). For materials, the thermal transmittance coefficient (also known as U-value) is defined as the amount of heat that passes per hour through 1m2 of a construction element with thickness d (m), when the difference in the still air touching the two surfaces of the element is kept constant and equal to 1°C. The Thermal Transmittance Coefficient is measured in W/m2K. The lower the value of this coefficient, the more insulating a material or building element is.
See all thermal transmittance coefficients for frames in energy-efficient opening frames
