Refrigeration and Air Conditioning
Question
A central air conditioning system shall be designed for a restaurant based on the following design data:
- Seating capacity: 200 people
- Ventilation rate: 10 L/s per person
- Indoor condition: 25°C dry bulb, 60% relative humidity
- Outdoor condition: 32°C dry bulb, 27°C wet bulb
- Room sensible load: 70 kW
- Room latent load: 30 kW
- Supply air temperature: 20°C
- Air temperature rise due to return fan power: 2°C
- Coil Apparatus Dew point (ADP): 14°C
Carry out the following:
i. Sketch a plant layout of the air conditioning process showing the air flow to and from the restaurant, mixing box and cooling coil, supply and return fan, and name all state points.
ii. Sketch the process on the psychrometric chart, identify all the state points named in i on the chart, and determine the following:
a. Volume of supply air to the restaurant
b. Coil cooling load
c. Coil sensible heat factor
d. Coil bypass factor
e. Temperature rise of supply air due to supply fan power
f. Condensate removed by the coil in kg/s
Assume the density of air to be constant at 1.2 kg/m³ and neglect duct heat loss.