A U-value, Time Lag, and Decrement Factor calculator opaque wall or roof surfaces.
OPAQUE calculates the U-value, Time Lag, and Decrement Factor for wall or roof opaque surfaces composed of a single or multiple layers. These can be used to calculate the Heat Gain or Loss through the surface. Composite surfaces are constructed by the user from a library of materials and displayed in two or three dimensions. In addition, 2-D plots of Outdoor and Sol-Air Temperatures, Radiation variables, and Heat Gain/Loss through the envelope can be displayed.