A room 7m x 6m x 3m high is to be electically heated to maintain the inside temperature at 20 C, when it is 0 C outside. The room has 2 windows each 1.2m x 1.8m and a sliding glass door 2.4m x 2.1m. The transmission coefficients u in Wm^2/C are given below.
Floor: concrete slab (100mm thick) : 11.5 W/m^2/C
Walls: Cavity Brick (280mm thick) : 2.0 W/m^2/C
Windows and door (Single glazed) : 5.8 W/m^2/C
Ceiling: (do not consider a roof) : 1.0 W/m^2/C
Ignore the effects of furnishings, presence of humans, orientation to sun or any wind exposure
Assume:
There is no requirement to heat the air in the room
Calculate the power rating of the electric heater required to maintain the required temperature.