Calculate the heat up time of solid homogenous box shaped object based on radiative heat transfer. Radiative heat transfer includes radiation from furnace walls, flames, radiating gases (carbon dioxide and water), radiation from the object itself and finally reflection of incoming radiation (assuming transmission = 0). To do a detailed calculation knowledge of emissivity of surfaces, emissivity of furnace gases, view factors, beam lengths and must also be known. In most cases the value of the received radiation and the emitted radiation from the object are close. The difference is the energy absorbed by the object.
