The room design cooling load is 3600 Btu/hr. The enthalpy of air leaving the cooling coil is 23 Btu/lbma. The room condition is 75 F db and humidity ratio of 0.01 lbmv/lbma. The air specific volume at 13.5 ft3/lbm. Determine the supply airflow rate to the room, Q in CFM 5. Determine the rate at which heat must be added in Btu/hr to a 6000 cfm airstream passing through a

The sum of the normal stresses does not change as the stress state rotates through an angle. a)-trune b)- false

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

Air at a pressure of 1atm and a temperature of 40 c is in parallel flow over the top surface of a flat plate that is heated to a uniform temperature of 120 c. the plate has a length of 0.40m (in the flow direction) and a width of 0.15m. the reynolds number based on the plate length is 50, 000. what is the rate of heat transfer from the plate to the air? if the free stream velocity of the air is doubled and the pressure is increased to 10 atm what is the rate of heat transfer?