3. The air in room is to be maintained at TRA=24C and RHRA=50%. The outdoor air is very hot and extremely dry, at TOA=35C and Tw=16C. The cooling load is 10 kW, of which 60% is sensible. The supplied air is made by evaporative cooling of water into a pre-cooled outdoor air. The injected water has an enthalpy of 200 kJ/kg, and the outdoor air is pre-cooled to the room temperature by a heat exchanger using exhaust air (if the heat exchanger efficiency is 100%). No returned air is used in this case. (a) Draw a complete air-conditioning cycle on the psychometric chart; (b) What is the temperature and relative humidity of the supplied air? (c) How much is water consumption rate for the humidification? (d) If the heat exchanger efficiency is just 70%, recalculate (b) and (c).
3. The air in room is to be maintained at TRA=24C and RHRA=50%. The outdoor air...
A building is designed for the following cooling loads. Room specific heat gain and latent heat gains are 310 kW and 100 kW respectively. The room is maintained at a dry bulb temperature of 25°C and relative humidity of 50%. The outdoor air is at 28°C with 50% relative humidity, 10% by mass of outdoor air is supplied to the building. If the air supplied to the room should be at a temperature lower than 18°C, detemine the following. (a)...
Moist air at 20C and 50% relative humidity enters a duct consisting of a heating section followed by an evaporative cooling process. The air is heated to 35C in the heating section. The air then enters the evaporative cooling section where liquid water is injected into the moist air. The moist air exits the evaporative cooling section at 60% relative humidity. A. Determine the specific humidity at the exit of the heating section. (5 of 45 points. Please input your...
On a typical autumn day, outside air with a dry bulb temperature of 15°C and 40% relative humidity is brought into a processing facility where it is to be used for a controlled storage chamber. The air must be heated to 37°C and humidified to 90% relative humidity. Calculate: (11 marks total) The relative humidity of the air when it is heated to 37°C, but BEFORE it is humidified. (No water has been added to the air yet). (2 marks)...
(10 pts) Six-thousand cubic feet per minutes (C.F.M.) of atmospheric air at 28°C (dry bulb) having a wet bulb temperature of 23°C is to be cooled in an air conditioning system. The air conditioning system lowers the dry bulb temperature of the air to 20° C. Cooling with dehumidification is accomplished using chilled water loop. The chilled water enters the loop at 5°C at a rate of 280 kg/min and experience a 5°C temperature increase. The atmospheric pressure is 1...
A room is to be air conditioned in the summer using water-cooled coils. The return air to air cooling unit has a sensible heat load of 100,000 Btu/hr and a latent heat load of 40,000 Btu/hr. The total heat load of the air going to the outside is 80,000 Btu/hr. Water enters the cooling coil at 40 deg.F and exits at 52 deg.F. From the total heat load on the room, use the result for water flow found above in...
Question NO. 3 (25 points) A space to be maintained at 27°C dry-bulb temperature has a rate of sensible-heat gain of 13 kW and a rate of latent heat gain of 8.5 kW. The system used to condition the space to the required conditions. The mass flow rate of air supplied to the space is 1.1 kg/s. Outdoor air at 38 °C dry-bulb temperature and 17 ℃ dew-point temperature is introduced into the system at a rate of 0.28 kg/s....
b) A cooling coil of an Air Handling Unit has dew-point of 8'C dry-bulb (db) temperature, and outdoor air enters the cooling equipment at 28 C d.b temperature and leaves at 16'C d.b temperature with mass flow rate of lkg/s determine: i) the contact factor (CF) ii) the volume flow rate iii) the by-pass factor iv) the sensible heat that removed from the outdoor air (1.5 mark) (1.5 marks) (1 mark) (2.0 marks) c) Explain the difference between "relative humidity...
b) A cooling coil of an Air Handling Unit has dew-point of 8'C dry-bulb (db) temperature, and outdoor air enters the cooling equipment at 28 C d.b temperature and leaves at 16'C d.b temperature with mass flow rate of lkg/s determine: i) the contact factor (CF) ii) the volume flow rate iii) the by-pass factor iv) the sensible heat that removed from the outdoor air (1.5 mark) (1.5 marks) (1 mark) (2.0 marks) c) Explain the difference between "relative humidity...
Prob. # 2] The temperature to be maintained in an office building is 26 C DB heat is 77.6 kW and the latent heat gain is 14.3 kW. Th accomplished by passing it through a spray-type heated to 18 C then supplied to the room. Find and 18 C W B. The sensible e cooling and dehumidifying of the air is washer with water chilled by refrigeration. The air is then a. the apparatus dew point temperature of washer, b....
al What is the physical interpretation of the wet-bulb temperature! b] During winter time a room is maintained at a steady temperature and humidity by an air-conditioning system shown. 200 m/min of room return air at 30°C. 50% relative humidity is first mixed with 20 m/min of outdoor 10°C. 20% relative humidity. The mixed air is then introduced to a heater where the temperature of the air is raised to 45°C and supplied to the room. [Note that air and...