Question

If we considered a hall to be a box 100 x 50 x 20 m³ (width x depth x height) in size with walls constructed from 20 cm thick fiberglass insulation (σ = 0.04 W / m K) over a 10 cm thickness of brick (σ = 0.3 W / m K),

a) What is the "R-value" of the walls (in SI and English Units)?

b) On a 35^o C day, how much heat is conducted through the walls if the interior temperature is maintained at 20^o C? (You may assume that the roof has the same thermal resistance as the walls and you should ignore the floor.)

c) A ton of refrigeration is the rate at which heat must be removed from 2000 lb of 32^o F water to freeze it in 24 hours. How many tons of refrigeration must be there to keep the hall cool on this day?

d) Does the hall have this much refrigeration?

Answer 1