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