1. Lecture Objectives: Continue with air-conditioning (psychrometric)
by looking into swimming pool example
homework assignment problems
Look at the cooling side of air condition
solve some problems related to the cooling system efficiency

2. Heat pump example A recreation center Heat Pump Ice Rink Swimming pool
Condenser
Evaporator
85-89oF
30oF
Consumes heat energy
Rejects heat energy
Electric power
for a compressor

3. Swimming pool energy and mass balance

4. Evaporation Heat loss by evaporation: hm
Tpool
Tair
pool
W s W ≈ hm Ws
Tpool
Wair
pool
Depends on the air speed and even
more on the condition of the water surface
(people splashing in the water)
Further analysis can be conducted in the psychrometric chart

5. Air conditioning in Air Handling Units (AHU)
Fresh
(outdoor)
air
Cooling
coil
Heating coil
damper
Fan (pull)
Fan (push)
mixing
Recirc.
air
Filter
Swimming pool

6. Air Handling Unit (AHU) Configurations

8. HW Assignment
Textbook (Thermal Environmental Engineering) problems: 8.1, 8.8, 8.13, 8.20 Need to talk about: - humidification and - heat recovery

9. Humidification (steam or air washer)
Steam humidifier
Air washer (mister)

10. Cooling Cycle (we discussed this but we need some numerical examples)
We need: COP = (h3-h2)/(h4-h3)

11. T-S diagram (water)

12. P-h Diagram (water)

13. P-h Diagram for R22

14. Example A) Calculate the COP when: ambient temperature is 30ºC
Cooling coil (CC) is 10ºC
Assume that :
condensation is 10ºC above ambient temperature
and evaporation is 10ºC below CC temperature B)
How much electricity you need to provide
1 ton of cooling ?