A one room building without windows measures 6.1m x 9.1m x 2.7m, and the four walls are covered with a 0.076 m layer of glass-wool insulation. The inside walls of the room are to be maintained 21 .lC when the outside wall temperature is l . 1C. How much heat must be supplied to the room each hour in order to maintain the desired temperature? If this heat is to be supplied by an electric heater, what should be the power rating of the heater? W = 0.035 W/mgg