1. MATLAB based design software for greenhouse evaporative cooling system
Wei Fang
Dept. of Bio-Industrial Mechatronics Engineering
National Taiwan University

2. design of pad and fan system
Objective
Develop Software for the
design of pad and fan system

3. Misleading catalogue information

4. Pad & Fan is powerful, but can not create miracle

5. ∵High T and high RH does not co-exist at most of the time
Pad&Fan is useful in Taiwan, all thought Taiwan is considered High T and RH
∵High T and high RH does not co-exist at most of the time

6. Required good design & Maintenance

7. Proper design
Bleed off end
Bleed off tube to floor drain or outside

8. Typical WBD (wet bulb depression) of plain area in Taiwan

9. Max. T drop using Fad&Fan in TaiwanoC %
WBD (Wet Bulb Depression) = dry bulb Temperature – wet bulb Temperature
T = WBD * Efficiency

10. Software development Tool
MATLAB (Mathworks, USA)
Popular among Engineers
Recent Textbook in Agr. Eng.
Takakura and Fang (2002) : Climate under cover -- dynamic simulations of bio-engineering systems using MATLAB. Kluwer Academic Publisher.
Cundiff and Mankin (2003)：Dynamics of biological systems. ASAE.

11. PFD (Pad_Fan_Design) Output： Input： System operating curves
Fan curves & pressure drop curves
Drawings of GH in 3D
Length of Pad required
Flow rate of Pump
Size of Sump
Makeup water required
Input：
Dimension of GH
Design criteria
Number of fans
Types of Pad

12. PFD window1 Enter GH dimension Type of roof Interval between posts
Metric,or English units
Type of roof
3 types available
Interval between posts
No. of bays per post
Misc.

13. PFD window 2 Select 1 algorithm out of 3 NGMA/ACME Munters
Air change ROT

14. PFD window 3 Number of fan required (guess value) Select type of pads
9 models of Euromme fans
Select type of pads
4 types available
Design facing velocity
Extra pressure drop
Required pad area, length
Calculated pump flow rate
Calculated sump size
Calculated makeup water

15. PFD window 3 In m3/s, in m3/m2/min Display GH in 3D
Display Fan & pad curves
In m3/s, in m3/m2/min
Display GH in 3D
Show more info. on Pads

16. Operating pt.

17. GH with Gable roof

18. GH with circular arch roof

19. GH with saw-tooth roof

20. Zoom out GH

21. Rotate in 3D

22. More info. on Pads

23. More info. On pads (cont.)
Pressure drop of pad under various wind speed
Pad efficiency under various wind speed

24. Fool proof design

25. Conclusion 1
The software developed can be served as teaching/research/design tool.
The software allows users to pick their options from currently available commercial products most popular in Taiwan, including：
9 fans，4 pads
3 roofs，
3 design criteria

26. Conclusion 2 The software provide fool proof design，including：
Interval between fans installed to check too much or too little fans
Comparison on Pad length and GH length
The software provide flexible outputs，including：
Fan curves, pad curves and system operating point
GH drawings in 3D and allow for rotate,zoom in and out
Pump, sump, makeup water requirement