1st Trial –

I placed vegetables i.e. cauliflower and tomato in fridge and note down the temperature.

Day 1 :

 Sr.no. Time Outside Temperature(°C) Inside Temperature(°C) 1. 12:30 PM 27.3 21.7 2. 01:30 PM 29.9 23.3 3. 02:30 PM 29.8 22.6 4. 03:30 PM 28.4 23.3 5. 04:30 PM 28.2 23.1 6. 05:30 PM 27.9 22.9

Day 2 :

 Sr.no. Time Outside Temperature(°C) Inside Temperature(°C) 1. 10:00 AM 25.2 20.5 2. 11:00 AM 26.1 21.6 3. 12:00 PM 28.7 23.4 4. 01:00 PM 28.9 22.6 5. 02:00 PM 29.9 23.2 6. 03:00 PM 29.6 23.4 7. 04:00 PM 28.9 22.9 8. 05:00 PM 27.5 22.5

Weight Loss

 Vegetables % weight loss Evaporative fridge Outside Tomato 16.65 17 Cauliflower 20 20

Problem – Here we get only 6°C temperature difference and very high weight loss in evaporative fridge which is nearly equal to outside.

Next Action – We will close the whole structure by using jute pads.

2nd Trial

Temperature-

DAY 1:

 Time Inside temp. Outside temp. 02:00 pm 24.8 32.9 03:00 pm 25.3 32.8 04:00 pm 23.2 32.6 05:00 pm 22.8 31

DAY 2:

 Time Inside temp. Outside temp. 10:00 pm 22.4 30.4 11:00 pm 24.5 32.5 12:00 pm 27.3 35.2

Weight loss:

Table : % Weight loss in evaporative fridge, refrigerator and outside

 Vegetables % Weight loss Evaporative fridge Refrigerator Outside Tomato 0.6 0.35 0.95 Fenugreek 21.3 6.5 29

After 12 hrs:

 Vegetables % Weight loss Evaporative fridge Refrigerator Outside Tomato 0.27 0.2 0.45 Fenugreek 6.6 2.56 19.58

After 36 hrs :

 Vegetables % Weight loss Evaporative fridge Refrigerator Outside Tomato 0.53 0.12 1.13 Fenugreek 6.4 3.4 31.87

Problem – After covering whole model of fridge we get more temperature difference (i.e. 8 to 9°C temperature difference) between inside and outside of the fridge but vegetables requires more temperature difference (i.e cooling) for preservation. Weight loss of vegetables in evaporative fridge is less than outside and trial 1st also. But at this time weight loss in evaporative fridge is quite more than refrigerator.

Observation – I observed that the water which is falling on jute curtains, blockage the air which passing through the holes of jute curtains i.e decreases its porosity. Because of this, we get the temperature difference but we cannot maintain relative humidity that’s why cooling efficiency decreases and vegetables loses its weight.

Action –

1. We decided to take cooling fans inside the evaporative fridge and take the readings of temperature.
 Inside temp. Outside Temp. 20.9 26.8 23.8 30.9

Observation – here we get 5 to 7°C temperature difference. But I observed the cooling fans only circulates inside air.

2. After this we decided to take readings by stopping water which falling on jute bags after 10 minutes.
 Inside Temperature Outside temperature 18.4 31.6 17.8 31.8 22.5 31.5

Trial 3

I enclosed the whole fridge and remove cooling fans. Place the exhaust fan (29watt) on the upper side and cooling fan at (bottom) back side of the fridge. Connect timer or energy switch to motor which recirculates the water in fridge. By using timer, I turn on pump, exhaust fan for some duration and then timer goes off for some duration.

TIMER SETTINGS –

 TIMER FOR TIME ON OFF Pump 12 sec. 1 min. Exhaust fan 8 sec. 21 sec.

Temperature