Question

One winter day, the climate control system of a large university classroom building malfunctions. As a result, 500 m3 of excess cold air is brought in each minute. At what rate in watts must heat transfer occur to warm this air by 10 °C (that is, to bring the air to room temperature)? unit Preview P=

Answer 1

Given,

The volume, V = 500 m³

The density of air, $\rho$ = 1.29 kg/m³

T = 10 ^o C

We know,

The rate at which the heat must transfer, P = Q / t

Where,

Q is heat transfer, = mc$\Delta$T

=> P = mc$\Delta$T / t

P = $\rho$ V c $\Delta$T / t

c is the specific heat = 721 j / kg ^o C

t = 60 sec

P = (1.29) (500) (721) (10) / 60

P = 77507.5 W

P = 77.5 kW