Chapter 6 - The Second Law of Thermodynamics - Problems - Page 326: 6-156

A

$\dot{V}=2.4m\times200m^2\times 1/h=480\ m^3/h,\ \rho=1.2\ kg/m^3$ $\dot{m}=\rho.\dot{V}=576\ kg/h$ $m=\dot{m}\Delta t,\ \Delta t=10h$ $m=5760\ kg$ $Q=mc_p\Delta T,\ c_p=1.005\ kJ/kg.°C,\ \Delta T=(32-22)°C$ $Q=57888\ kJ=16.08\ kWh$ $COP=Q/W=3.2$ $W=5.025\ kWh$ $C=W\times p,\ p=\$0.10/kWh$ $C=\$0.50$