U 0.60 metric = R-9.1 imperial: the thermal conversion that every professional should master
U 0.60 metric = R-9.1 imperial: the thermal conversion that every professional must master, especially in the field of high-performance windows. The first question to ask is simple: in which system is the U value expressed? Metric (W/m²·K) or imperial (Btu/h·ft²·°F), the two systems are not directly comparable, and a misinterpretation can transform an excellent window into a product that seems average… simply because the conversion has not been done.
