Example-1 An uncovered swimming pool loses 1.0 in of water off of its 1000 ft² surface each week due to evaporation. The heat of evaporation for water at the pool temperature is 1050 Btu/lb. The cost of energy to heat the pool is $10.00 per million Btu. A salesman claims that a $500 pool cover that reduces evaporative losses by two third will bay for itself in one in 15-week swimming season. Can it be true? Example-2 Calculate the thermal resistance and rate of heat transfer through a pane of window glass (k = 0.81 W/m K), 1 m high, 0.5 m wide, and 0.5 cm thick, if the outer temperature surface temperature is 24.5 °C and the inner surface temperature is 24.0°C