[1] (25%) Air enters a compressor operating at steady state with a pressure of 14.7 lbf/in.2 , a temperature of 90 oF, and a volumetric flow rate of 1000 ft3 /min. At the exit, the pressure is 100 lbf/in.2 and the temperature is 410 oF. Using the ideal gas model, determine the diameter of the exit duct in ft so the exit air velocity does not exceed 700 ft/s.

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