Question

A house is being designed to use a thick concrete floor mass as thermal storage material for solar energy heating. The concrete is 30 cm thick and the area exposed to the sun during the daytime is 4 m × 6 m. It is expected that this mass will undergo an average temperature rise of about 3°C during the day. How much energy will be available for heating during the nighttime hours? 

Answer 1

C.V. The mass of concrete.

Concrete is a solid with some properties listed in 

V = 4 × 6 × 0.3 = 7.2 m³ ;

m = ρV = 2200 kg/m³ × 7.2 m³ 

= 15 840 kg

∆U = m C ∆T = 15840 kg × 0.88 KJ/kg K x 3 K =  41818 kJ = 41.82 MJ