Passive Cooling Through Evaporative Towers
Cooling Systems
Passive Down Draught Evaporative Cooling (PDDEC) System
Provides cooling without significant energy use, resulting in a fresh, cool environment
Importance ◦ Cooling towers provide passive cooling in hot, dry
climates.
◦ Results in eco-friendly, low impact climate control solutions.
◦ Provides a more comfortable living space.
◦ Cost effective.
Indirect cooling
Air intake
Water distribution
Evaporation
Water storage
Cooled space
On hot, dry days, the cooling tower will lower the temperature of the air exiting the tower to below the ambient air temperature via the evaporative process.
By performing consecutive experiments on a controlled tower, we can determine the most effective evaporative technique that can be utilized in cooling tower systems
CONSTANTS VARIABLES
Two towers
Both used identical systems
Wind Collection
Water Distribution
Water Retention
Control and test towers Each tower was set up
with a different air/water mixing systems
2/6/13
Results Test 1 Data
Foam panel tower had an average interior-to- exterior air difference of 11.88°F
This is 6.72°F cooler than the cloth tower
The foam panel became our control
High (°F) Low (°F) Average (°F)
External
Temperature
72.83 59.31 67.40
Relative Humidity 44.33% 23.11% 32.54%
Foam Panel Internal 61.25 50.58 55.52
Cloth Internal 65.75 57.33 62.24
Foam Panel
Difference
14.95 8.74 11.88
Cloth Difference 11.62 1.98 5.16
2/6/13
CONSTANTS VARIABLES
Both towers used rigid foam panels
Panels were placed in identical positions in the towers
Test tower had foggers installed
Control tower used a stream from ½ in. tube
2/6/13
Results Test 2 Data
Control tower had an average interior-to- exterior air difference of 7.32°F
This is 3.5°F cooler than the test tower
Control tower remained our control for the next phase
2/6/13
High (°F) Low (°F) Average (°F)
External
Temperature
70.54 56.43 63.56
Relative
Humidity
74.21 50.95 61.84
Control
Internal
61.03 52.67 56.24
Experiment
Internal
65.62 55.04 59.75
Control
Difference
11.34 3.26 7.32
Experiment
Difference
5.81 1.30 3.82
CONSTANTS VARIABLES
Both towers used rigid foam panels with water stream distribution
Physical structure of the towers are identical
Test tower had a small fan installed for forced airflow
Control tower used the same passive airflow technique as before
2/6/13
Results Test 3 Data
Test tower had an average interior-to- exterior air difference of 23.27°F
This is 4.85°F cooler than the control tower
Test tower proved to be more effective
2/6/13
High (°F) Low (°F) Average (°F)
External
Temperature
99.32 82.18 91.74
Relative
Humidity
33.97% 11.20% 19.63%
Control
Internal
88.76 66.81 73.28
Experiment
Internal
74.08 63.56 68.44
Control
Difference
24.52 8.79 18.42
Experiment
Difference
30.74 16.13 23.27
Proposing 2 towers per wing to cool the space
May incorporate a duct system to evenly disperse the cooled air
Test 2 demonstrated less water loss in the fogger test tower
Test 3 demonstrated higher performance in the fan test tower, but at the cost of energy consumption
Water loss due to evaporation and splashing
Could not determine if factors such as air temperature and relative humidity, although linked, were more important than the other
Data suggests these cooling towers perform best on hot, dry days
Towers with the greatest air and water flow performed the best
Concluded that the volume of air and water mixed is most significant in the effectiveness of total cooling provided by the towers.
Applicable to residential setting