RAT EQUATION THERMAL HEAT TRANSFER
When Solar Radiation strikes Glass sheet, it is partly reflected, partly absorbed in the thickness of the glass and partly transmitted.
RAT Equation? When the combined UV, visible light and infrared (solar energy) strikes glass it is reflected (R), absorbed (A) and transmitted (T) in different proportions, depending on the type of glass involved. This gives us the RAT Equation which accounts for 100% of solar energy.
Thermal Heat: Transfer Heat is transferred either by convection (upward warm air currents), conduction (passing from one object to another) or radiation (where heat passes through space to an object where it is reflected, absorbed or transmitted). The absorbed portion of the energy is subsequently dissipated by reradiation (or emission) to both the outside and inside, in varying proportions, dependent on the type of glass and external weather conditions
Shading co-efficient(SC) : The ratio of total solar radiation through a particular glass type, relative to the total solar radiation through 3mm clear float glass. This show the glass performance in reducing heat.