A plane wall (k=1W/mK) has a thickness of 0.3 m, height of 2 meter, and width of 1 m. It undergoes uniform volumetric heat generation of 1000 W/m3. The left side of the wall is insulated and the right side is cooled via convection with heat transfer coefficient of 5 W/m2K and an air temperature of 25C. a) Find the temperature of the wall at its center and the temperature at the surface in contact with the air. b) If fins (l = 1 W/mK) were added to the rigth hand side, find the temperature of the wall in contact with the air (the base of the fins). The fins are rectangular and span the width of the wall with a thickness of 10 mm and a length of 75 mm. The spacing between fins along the heigth of the wall is 20 mm

Determine the time of the day and month of the year at which the peak sensible cooling load occurs for a top floor, north-eastern corner room of an office building in durban for the following conditions: floor area: 8 x 8 x 3 m east and north walls: 115 mm face brick (outside), 20 mm air space, 115 mm ordinary brick (inside) with 15 mm plaster roof construction: suspended plasterboard ceiling, 450 mm air space, 150 mm concrete, 75mm screed, waterproofing no heat transfer across other surfaces window area 3x 1,5 m high in north wall only. ordinary glass with venetian blinds. lights and occupants : from 07: 00 to 18: 00 average light density: 25 w/m2 number of occupants : 5 seated, light office work room temperature 24°c