Chapter:

Radiation-:-Exchange-between-Surfaces

An enclosure consists of four surfaces 1, 2, 3 and 4. The view factors for radiation heat transfers are
F 11 = 0.1
F 12 = 0.4
F 13 = 0.25
The surface areas A 1 and A 2 are 4 m2 and 2 m2. The view factor F 41 is