Optimization of Foggers and Fan-Pad System

09/09/24 – 13/09/24

Introduction:

The purpose of growing crops under polyhouse is to create optimum conditions for quality production. Among the factors affecting the production under polyhouse are mainly diseases and pest attacks which require constant monitoring and implementing control measures. It involves a deep understanding of plant biology as well as knowledge of specific pests and diseases that are most likely to affect polyhouse.

One of the primary preventive measures in disease management is maintaining a controlled and sanitized polyhouse environment that minimizes the risk of disease outbreak. This includes ensuring proper ventilation and air circulation, managing humidity and temperature. So, to prevent polyhouse crop from disease and insect attacks here in polyhouse of Vigyan Ashram, Pabal we are mainly focusing on environment inside polyhouse.

Fogging systems operate by creating a fine mist or ‘fog’ in the greenhouse, which reduces temperature and increases humidity level in a controlled manner. A fogging system primarily contains a high-pressure pump, a distribution network of pipes or tubes, and a series of nozzles. The high-pressure pump is very important for the system ;as it forces water through the distribution network in a controlled manner. As the water reaches the nozzles, it is atomized into microdroplets, and a fine mist or fog is created.

Fan-Pad System consists of exhaust fan at one end of the greenhouse and a pump circulating water through and over a porous pad installed at the opposite end of the exhaust fan. If all vents and doors are closed when fans are operated, air is pulled through the wetted pads and water evaporates. Removing energy from air lowers the temperature of the air being introduced into the greenhouse.

Methodology:

. 1) To collect temperature and humidity data inside polyhouse.

2) To measure the airflow rate and light intensity at various locations.

3) To check the flow rate of foggers.

4) To integrate and analysis above data to design algorithm for polyhouse automation.

As a part of my project decided to check the flow rate of foggers fixed in polyhouse.

Need to check the flow rate of foggers?

. 1) Evenly distribution of water throughout the fogger system.

2) To check how much water is discharged from each foggers.

Process:

1. There are total 84 foggers fixed in polyhouse. There are 12 lines each line contains 7 foggers. What I did is collected 36 PET bottles made containers out of it to hang on foggers, so that fogger should discharge it’s flow in container.
2. Each line contains 7 foggers, we hanged containers alternately to 3 foggers in each line.
3. Kept foggers ‘ON’ for 20 seconds and measured the collected water discharge in containers.
4. Repeated the same process 2 times.

Below table contains readings of flow rate measured.

Table: 1.1

Fogger lines	Containers	Flow rate(ml/20sec)(1)	Flow rate(ml/20sec)(2)
1	A1	65	50
	A2	200	200
	A3	125	130
2	B1	230	195
	B2	175	170
	B3	350	225
3	C1	60	60
	C2	140	150
	C3	190	190
4	D1	175	180
	D2	145	170
	D3	115	150
5	E1	120	120
	E2	165	170
	E3	140	160
6	F1	170	175
	F2	135	140
	F3	150	175
7	G1	150	160
	G2	135	175
	G3	145	150
8	H1	150	150
	H2	155	150
	H3	235	230
9	I1	145	160
	I2	160	165
	I3	145	150
10	J1	370	375
	J2	125	160
	J3	85	100
11	K1	140	155
	K2	85	135
	K3	175	170

15/9/24-18/9/24

From this day I started collecting temperature and humidity data by devices like hygrometer, digital thermo-hygrometer and air flow with the help of anemometer

Fig.no. 1.1 Graphical representation of temperature near cellulose pad inside and outside polyhouse in condition when fan pad system and foggers were off.

The above graph represents temperature rise data with respect to time. The data was collected with the help of  digital thermo-hygrometer. The above temperature data is of near cellulose pad inside and outside polyhouse in condition when fan pad systems and foggers were ‘OFF’. Overall, this condition was created to observe the temperature rise trend.

Time	⁰C outside	⁰C inside
11:00	29.7	30
11:20	29.8	29.9
11:40	31.1	30
12:00	30.9	33.3
12:20	31.1	34.8
12:40	32.4	34.9
13:00	32.5	34.9
13:20	34	36.8

Fig.no. 1.2 Graphical representation of temperature at the center of polyhouse in condition when fan pad system and foggers were off

The above graph represents temperature rise data with respect to time. The data was collected with the help of  digital thermo-hygrometer. The above graph represents the temperature rise at the center of poly-house in condition when fan pad systems and foggers were ‘OFF’. Overall, this condition was created to observe the temperature rise trend at the center.

Time	Temp. ⁰C
11:00	33.7
11:20	32.8
11:40	35.6
12:00	35
12:20	35.6
12:40	36.1
13:00	37
13:20	38.8

Fig.    Graphical representation of Temperature near exhaust fans inside and outside polyhouse  when only foggers were kept ‘ON’ within the above interval of time.

Time	⁰C  Inside	⁰C Outside
11:00	33.9	29.7
11:20	34.9	29.5
11:40	36.6	30.4
12:00	37.2	31.6
12:20	36.5	32.3
12:40	37.7	34.6
13:00	38.3	35.6
13:20	40	33.5

Date: 19/09/24

Data was coll

Fig.    Graphical representation of Temperature and Humidity at centre location inside the polyhouse  when only foggers were kept ‘ON’ within the above interval of time.

The graph represents temperature and humidity at the centre of polyhouse. Data was recorded with the help of data-logger located at the centre inside polyhouse, while the Fan-Pad System and Fogger system was ‘OFF’. Once, the temperature started increasing at it’s peak from 11:08 am the foggers were ‘ON’ and fast temperature decrease was observed till 11:11 am. It is observed between 11:14 am – 11:29 am the humidity was near 100 % or 100 % which stopped temperature drop, hence steady temperature can be seen.

Time	⁰C	RH (%)
11:08	42.06	42.28
11:11	35.13	78.45
11:14	32.42	95.06
11:17	31.91	97.28
11:20	31.86	100
11:23	31.98	100
11:26	31.42	100
11:29	31.20	100

Fig.    Graphical representation of Temperature and Humidity at centre location inside the polyhouse  when only foggers were kept ‘ON’ within the above interval of time.

Temperature and humidity data were taken from data loggers located at the centre of the polyhouse. The above temperature and humidity data were recorded while fan-pad system was ‘OFF’ ,the pads were dry. At 11:00 in morning the temperature raised at it’s peak was observed,  so from 11:07 am – 11:11 am the foggers were kept ‘ON’ to record the temperature drop and increase in humidity within the interval of time

Date: 20/9/24

Time	⁰C	RH (%)
11:07	42.32	47.27
11:08	41.97	57.29
11:09	39.73	69.26
11:10	37.98	72.24
11:11	35.04	85.9

21/09/24-22/09/24

1. Discussions on the above data by Dixit Sir and other members.
2. Graph preparation on basis of data recorded.
3. Blog writting.
4. Common lecture for all.

1/10/24

Temperature rise as the foggers are off
Time(AM)	Temp(°C)	RH (%)
10:20	35.04	86.94
10:21	35.25	87.32
10:22	35.54	84.18
10:23	35.93	84.82
10:24	36.3	80.09
10:25	36.51	76.57
10:26	36.47	76.75
10:27	36.44	77.23
10:28	36.53	75.81
10:29	36.79	74.71
10:30	37.14	73.87

Date: 2/10/24

Temperature rise analysis as soon as the foggers are off’
Time	Temp (°C)	RH (%)
10:24	35.9	84.49
10:29	37.12	80.42
10:34	38.99	69.86
10:39	40.2	63.25
10:44	41.03	58.06
10:49	41.8	57.14
10:54	42.46	42.46
10:59	43.05	52.66
11:04	43.63	51.05
11:09	44.26	49.5
11:14	44.58	44.58
11:19	44.86	48.91
11:24	45.45	46.83
11:29	45.72	44.6

8/10/24

Today, we discussed with Dixit sir about the calculations regarding volume of air to be exhausted by exhaust fans to get the assumed temperature. Below is the word file which provides details about the discussion.

9/10/24

Polyhouse data call was not taken due to poor weather conditions.

19/10/24

This calculations are done by considering absorption and emission of energy through polyhouse sheet i.e LDPE sheet, surface soil.

22/10/24

To determine the amount of heat emitted by LDPE sheet we measured the total LDPE cover over polyhouse GI skeleton.which was around 733.08 m^2.

21/11/24

There were blockages in nozzles of foggers. With the help of DBRT students from agriculture section we removed foggers and did cleaning of nozzles. We connected all the foggers and checked there efficiency. All foggers were working efficiently and no blockages were seen.

After finishing this work I took session of students on foggers and it’s uses , Fan-Pad Polyhouse and Naturally Ventilated Polyhouse.

For taking reading I turned off the water on pads and exhaust fans. At 1:13 pm temperature inside polyhouse was 37 degree ,at that time outer temperature was 27 degree, and here I started recording temperature drop by turning on foggers and exhaust fans. I got 11 degree temperature drop in 10 minutes i.e from 1:13-1:23. At 1:23 when I stopped foggers and exhaust fans the temperature was 25 degree. Now, we will see the temperature rise by keeping pads and exhaust fans off and will do calculations of heat removal in each 1 degree rise in temperature.