Problem 3 Air flows through a duct, past a specific location (point 1) at a rate of 2,500 L/s. At this location the dry bulb and wet bulb temperatures are measured to be 30°C and 22°C, respectively. a. Make use of the Psychrometric chart to find the enthalpy, specific volume, humidity ratio, and relative humidity of the air at point 1. b. If the air at point 1 flows past a heating coil and is heated to a temperature of 45°C, what is the rate at which heat is transferred to the air? C. If instead, the air at point 1 passes by a cooling coil and is cooled to 15°C dry bulb and 90% relative humidity, determine the following: i. Total rate at which heat is withdrawn from the air (COOLING = ȧTOTAL) (Note: Take hw = 62.97 kJ/kg) ii. The sensible heat transfer rate (as) 9s iii. iv. The sensible heat factor (note that this nothing fancy. It is just SHF = Mass flow rate of condensate (mw), grams/hour ȧtotal Fig. 2-10 SI ASHRAE Psychrometric Chart H ASHRAE PSYCHROMETRIC CHART NO.11 NORMAL TEMPERATURE BAROMETRIC PRESSURE: SEA LEVEL 101.325 kPa COPYRIGHT 1992 AMERICAN SOCIETY OF HEATING, REFRIGERATING AND AIR-CONDITIONING ENGINEERS, INC. 14 108 20 30 BENBIBLE HEAT TOTAL HEAT ENTHALPY HUMIDITY RATIO 40. -10 - ENTHALPY k SATURATION TEMPERATURE C 80 20, 100 30 19% RELATIVE HUMIDITY 10 20 30 DRY-BULB TEMPERATURE, "C 28 IDITY RATIO w