1. A tungsten fi lament of a lamp is at 2500°C. What percent of the total radiant energy is in the visible range? 2. Determine the view factor between a 1 m 2 skylight, oriented as shown, above a...

1. A tungsten fi lament of a lamp is at 2500°C. What percent of the total radiant energy is in the visible range?

2. Determine the view factor between a 1 m²
skylight, oriented as shown, above a floor which measures 20 m
 28 m.

3. Evaluate the percentage of daylight entering through a store window A₁
that impinges on the floor area A₄
located relative to A₁
as shown in Fig. P. 7.37. Assume that the light through the window is diffuse.