Table 2 Eco-cooler effects on temperature, humidity, wind speed and atmospheric pressure for six eco-cooler designs

From: Evaluating the effectiveness of the ‘eco-cooler’ for passive home cooling

 

Design 1: larger bottles

Design 2: smaller bottles

Design 3: flipped board (suction)

Design 4: nozzle extension

Design 5: reduced air resistance

Design 6: mixing air at nozzle

Short tests

 Duration (minutes)

20

20

20

20

20

20

 Number of measurements per experiment (N)

126

126

126

126

126

126

40 °C, 70% humidity

Eco-cooler effect estimates for temperature ( °C)

 4.0 m/s

0.00 (−0.21–0.21) 0.984

0.11 (0.04–0.18) 0.179

0.02 (−0.02–0.05) 0.357

0.11 (0.02–0.20) 0.016

0.20 (−0.43–0.83) 0.522

0.11 (0.06–0.16) <0.001

 2.0 m/s

0.01 (−0.10–0.13) 0.855

0.11 (0.00–0.21) 0.042

0.02 (−0.08–0.12) 0.662

0.13 (0.09–0.17) <0.001

0.10 (0.04–0.17) 0.002

0.11 (0.02–0.19) 0.012

 0.2 m/s

−0.18 (−0.20 to −0.16) <0.001

−0.04 (−0.04–0.11) 0.329

−0.05 (−0.06–0.04) <0.001

−0.17 (−0.22 to −0.11) <0.001

−0.08 (−0.11 to −0.06) <0.001

−0.13 (−0.20 to −0.15) <0.001

40 °C, 70% humidity

Eco-cooler effect estimates for humidity (%)

 4.0 m/s

−0.40 (−1.50–0.70) 0.470

−0.47 (−1.45–0.51) 0.338

−0.00 (−0.99–0.98) 0.995

−0.42 (−0.85–0.01) 0.057

−0.67 (−1.76–0.42) 0.221

−0.40 (−0.90–0.13) 0.139

 2.0 m/s

−0.38 (−1.88–1.12) 0.614

−0.44 (−0.94–0.06) 0.086

−0.05 (−1.24–1.13) 0.928

−0.43 (−2.01–1.15) 0.585

−0.33 (−1.95–1.29) 0.683

−0.33 (−1.08–0.42) 0.382

 0.2 m/s

0.33 (−0.53–1.12) 0.614

−0.23 (−0.98–0.52) 0.533

0.17 (−0.73–1.07) 0.704

0.42 (−0.03–0.86) 0.066

0.22 (−1.15–1.58) 0.751

0.40 (−1.23–2.02) 0.622

35 °C, 60% humidity

Eco-cooler effect estimates for temperature ( °C)

 4.0 m/s

0.09 (−0.06–0.24) 0.226

0.11 (−0.12–0.35) 0.334

−0.02 (−0.28–0.24) 0.870

0.13 (0.05–0.20) 0.001

0.08 (0.02–0.14) 0.009

0.09 (0.01–0.17) 0.031

 2.0 m/s

0.04 (−0.04–0.12) 0.320

0.12 (−0.01–0.24) 0.073

0.02 (−0.14–0.19) 0.775

0.11 (0.05–0.17) <0.001

0.05 (−0.10–0.19) 0.508

0.08 (−0.00–0.17) 0.625

 0.2 m/s

−0.02 (−0.09–0.05) 0.547

0.02 (−0.01–0.04) 0.269

−0.07 (−0.09 to −0.06) <0.001

−0.16 (−0.2 to −0.1) <0.001

−0.10 (−0.14 to −0.06) <0.001

−0.15 (−0.20 to −0.10) <0.001

35 °C, 60% humidity

Eco-cooler effect estimates for humidity (%)

 4.0 m/s

−0.54 (−2.31–1.24) 0.543

−0.55 (−1.5–0.50) 0.295

0.09 (−1.65–1.84) 0.917

−0.48 (−1.07–0.11) 0.105

−0.31 (−2.86–2.25) 0.810

−0.32 (−0.57 to −0.08) 0.012

 2.0 m/s

−0.35 (−1.39–0.70) 0.504

−0.49 (−1.04–0.06) 0.079

−0.06 (−0.72–0.59) 0.846

−0.36 (−0.84–0.12) 0.139

−0.20 (−0.51–0.11) 0.208

−0.30 (−1.01–0.48) 0.474

 0.2 m/s

0.07 (−0.19–0.33) 0.575

−0.15 (−0.34–0.03) 0.107

0.63 (−1.41–2.67) 0.537

0.49 (−0.19–1.18) 0.151

0.33 (−0.03–0.70) 0.071

0.63 (−1.36–2.62) 0.523

Long tests

 Duration (hours:minutes)

14:28

14:24

NA

15:13

15:18

4:46

 Number of measurements per experiment (N)

5256

5316

 

5446

5658

1752

40 °C, 70% humidity

Eco-cooler effect estimates for temperature ( °C)

 4.0 m/s

0.02 (−0.05–0.09) 0.562

0.11 (0.08–0.14) <0.001

NA

0.10 (0.07–0.13) <0.001

0.09 (0.06–0.12) <0.001

0.09 (0.01–0.18) 0.028

40 °C, 70% humidity

Eco-cooler effect estimates for humidity (%)

 4.0 m/s

−0.28 (−0.53 to −0.02) 0.032

−0.44 (−0.67 to −0.20) <0.001

NA

−0.33 (−0.77–0.11) 0.146

−0.29 (−0.56 to −0.02) 0.033

−0.28 (−0.68–0.13) 0.179

Wind speed

Wind speed after eco-cooler (m/s)

 

Design 1

Design 2

Design 3

Design 4

Design 5

Design 6

 

A

B

A

B

A

B

A

B

A

B

A

B

 4.0 m/s

1.41

0.69

3.80

4.01

1.29

1.34

2.75

3.30

1.85

2.03

3.14

3.23

 2.0 m/s

1.02

0.50

2.02

2.02

0.65

0.66

1.65

1.77

0.96

1.06

1.58

1.65

 0.2 m/s

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

  1. The effects of the eco-cooler on temperature and humidity were measured with six sensors placed in the climate chambers. Three of these sensors were placed before the eco-cooler and three after the eco-cooler. We used linear regression to quantify the eco-cooler effect (i.e., the difference between the sensor measurements before and after the eco-cooler). The numbers shown for each eco-cooler design and climate scenario are (from right to left in each cell): the eco-cooler average effect size, and the 95% confidence interval (in parentheses) and the p value of the effect size.
  2. Wind speed and atmospheric pressure estimates were empirical spot measurements.
  3. High humidity = 70%, medium humidity = 60%, low humidity = 40%.
  4. High temperature = 40 °C, medium temperature = 35 °C, low temperature = 30 °C.
  5. Difference in means are significant if temperature is ±0.5 °C and humidity is ±4.5%.
  6. Short duration tests consisted of three wind speeds: 4 m/s, 2 m/s and 0.2 m/s. Long duration tests consisted of one wind speed: 4 m/s.
  7. Wind speed tests corresponding to A and B were conducted under climatic chamber conditions of 70% humidity, 40 °C, and 60% humidity, 35 °C respectively. Bolded numbers represent an increase in wind speed after the eco-cooler.
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