Direct evaporative cooling system powered by both solar PV and existing AC power sources.

1. 1
Design Report
on
Cooling fan for Kiosk Stall
(Course: Design and Engineering for sustainability)
Submitted by Submitted to
Sheshadri Shekhar Rauth Dr. Bala Pesala

2. 2
Contents
SL. N. Contents Page No.
1 Introduction & Defining Need 3
2 Concept Generation 5
3 Concept Selection 7
4 Product Design & Features 8
5 Components Need for Hardware Implementation 10
6 Proposed Circuit Diagram and description 11
7 3D Design & Final Product 13
8 Analysis & Test Result 14
9 References 15
Cooling fan for Kiosk Stall

3. 3
CHAPTER 1
INTRODUCTION AND DEFINING NEED
1.1 Introduction:
Every day when we go through the roads, we see many of small shops. Every day in
those shops small business are continuing throughout the day. It might be vegetable
shop, tea shop or small food shop etc. This whole day’s work gives them some earning
through their livelihood. In our daily life path, we also find them according to our need.
But there is also some area in India, where electricity is not abundantly available. Then
in such situation they need to continue their work in warm sunny condition. Even due
to lack of much light, they cannot extend their small business after little darkness by
evening. Again also in urban area, the hot weather problem remain same. So to get rid
of those issues, one system is needed that gives cooling effect and also will give light.
There are different types of coolers available in the market. Currently available coolers
need external electricity supply and also not having lighting system along with it. So it
is very important to develop a cooler that will consume less or zero power from existing
power supply and also should have to be with a lighting option for both rural small
shops and urban kiosk stalls.
Fig.1 One small kiosk stall model and one small tea shop in Orissa [1]
Cooling fan for Kiosk Stall

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1.2 Defining Need
Cooling system with lighting option for small kiosk stall (such as tea, food, vegetable
etc.) holder who works inside, from 10 AM to 8 PM.
Need Priority:
Many cooling systems are available in market, its known that shop holders are not fully
satisfying with those existing system.
S. No Needs Specification which refers to Need Units
1 Cooling Temperature 0
C
2 Enough lighting Luminosity Lux
3 Low cost Cost Rs
4 Portable Portable ---
5 Durable Life time Years
6 Less weight Mass Kg
7 Less maintenance Maintenance ---
8 Easy to operate Air flow control ---
Table.1: Needs Priority
Cooling fan for Kiosk Stall

5. 5
CHAPTER 2
CONCEPT GENERATION
The cooling process can be done by various processes. Some kind of process is given
bellow.
2.1 Different Concepts
Central Air Conditioners and Heat Pumps
Central air conditioners and heat pumps are
designed to cool the entire house. In each system, a
large compressor unit located outside drives the
process; an indoor coil filled with refrigerant cools
air that is then distributed throughout the house
via ducts. Heat pumps are like central air
conditioners, except that the cycle can be reversed
and used for heating during the winter month. Fig.2 Central air conditioners[2]
Room Air Conditioners
Room air conditioners are available for mounting in
windows or through walls, but in each case they work the
same way, with the compressor located outside. Room air
conditioners are sized to cool just one room, so a number
of them may be required for a whole house. Fig.3 Room AC[3]
Evaporative Coolers
Evaporative coolers, sometimes called swamp coolers, are
less common than vapor compression (refrigerant) air
conditioners, but they are a practical alternative in very dry
areas. They work by pulling fresh outside air through moist
pads where the air is cooled by evaporation. The cooler air
is then circulated. Fig.4 Evaporative Cooler[4]
Cooling fan for Kiosk Stall

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This process is very similar to the experience of feeling cold when you get out of a
swimming pool in the breeze. An evaporative cooler can lower the temperature of
outside air by as much as 30 degrees.
Ductless Mini-Split Air Conditioners
Mini-split systems, very popular in other countries, can be
an attractive retrofit option for room additions and for
houses without ductwork, such as those using hydroid heat.
Like conventional central air conditioners, mini-splits use an
outside compressor/condenser and indoor air handling
units. The difference is that each room or zone to be cooled
has its own air handler. Each indoor unit is connected to the
outdoor unit via a conduit carrying the power and the Fig.5 Ductless Mini-Split AC[3]
refrigerant lines. Indoor units are typically mounted on the wall or ceiling.
Cooling fan for Kiosk Stall

7. 7
CHAPTER 3
CONCEPT SELECTION
Concept selection is the selection of concept from the generation of concepts. Those
have to be filtered according to needs and different aspect of concepts. After the first
filtration, the concept should be compared and filtered based on the Need priority and
weightage matrix.
From the previous generated concepts selected concepts are compared to choose the
concept for designing.
S. No Need
Priority
Weightage Central ACs
and Heat
Pumps
Room
AC
Evaporative
Coolers
Units
1. Cooling 1 4 3 2 O
C
2. Portability 0.8 1 1 4 ---
3. Initial cost 0.8 1 2 4 Rs
4. Weight 0.7 1 2 4 Kg
5. Running
cost
0.8 2 3 4 Rs
6. Maintenance 0.5 3 3 3 ---
7. Life time 0.5 4 4 3 Year
8. Air flow
control
0.7 4 4 4 ---
Total 20 22 28 18
Table.2: Technical parameters of product
After the comparison of concepts from the filtered concept it is cleared that evaporative
cooling is best suit for that purpose. So, now evaporative cooler is chosen for
development.
Cooling fan for Kiosk Stall

8. 8
CHAPTER 4
PRODUCT DESIGN AND FEATURES
Based on the previous table I can see that it is good to go for evaporative cooling. It has
to be designed for shop holders. So there should be included lighting option too.
4.1 Product Features:
 Solar based charging
 Evaporative cooling
 Led lighting
 Air flow control
 Switch
 Battery
 AC & DC charging option
 Battery charge and Water level indicator
Solar based charging
A solar charger employs solar energy to supply electricity to
devices or charge batteries. Here I am using this to charge the
battery, which will run the water pump, cooling fan and the LED
light. Charging circuit is used here. It can charge the battery
without available electricity. Only sun irradiance is needed. Fig.6 Solar panel
Evaporative cooling fan
They work by pulling fresh outside air through moist pads where
the air is cooled by evaporation. The cooler air is then circulated
through a house. This process is very similar to the experience of
feeling cold when you get out of a swimming pool in the breeze. Fig.7 Cooler diagram[5]
Here in the fan part, DC fan I have used.
Led lighting
There are led strips which will give light with switching from the top
of the cooler. Fig.8 LEDs[6]
Cooling fan for Kiosk Stall

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Air flow control
There is a switching control option to control the air flow speed.
Switch
Various switches are there to on or off the pump, on or off the fan,
speed control, light, ac/dc charging etc. Fig.9 Switch[6]
Battery
Battery is the dc storage device. Here I can charge it by both ac and dc
supply. The ac supply we are getting from the solar panel. From that
battery I am able to run pump, fan and led. Fig.10 Battery
AC & DC charging option
There are two options, where we can change the mode of charging by ac or dc.
Cooling fan for Kiosk Stall

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CHAPTER 5
COMPONENTS NEEDED FOR HARDWARE IMPLEMENTATIO
SL.N. NAME SPECIFICATIONS PICS.
1 DC pump 12V, 10W 1
2 DC fan 12V, 12W 1
3 Mosquito net --- 1
4 Grass wool 250 g ---
5 Plastic sheet 0.20 m2
6
6 Pipes 2 m 1
7 Battery 12V, 7.5 Ah 1
8 Wire 2 m 1
9 Switches 20V, 3A 4
10 Solar panel 16V, 8W 1
11 Rectifier --- 1
12 Charge controller --- 1
13 LED 0.5W 4
Table.3: List of Hardware required
Fig. 11 Making of cooling pad from grass wool and mosquito net
Fig. 12 Sheets to make the structure, DC fan, Battery, DC pump
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CHAPTER 6
CIRCUIT DIAGRAM AND DESCRIPTION
Fig.13 Circuit block diagram of the cooling system
As water is evaporated, energy is lost from the air, reducing the temperature. Two
temperatures are important when dealing with evaporative cooling systems.
Dry Bulb Temperature
 This is the temperature that we usually think of as air temperature, measured by
a regular thermometer exposed to the air stream.
Wet Bulb Temperature
 This is the lowest temperature that can be reached by the evaporation of water
only.
When considering water evaporating into air, the wet-bulb temperature, as compared to
the air's dry-bulb temperature is a measure of the potential for evaporative cooling. The
dry and wet bulb temperature can be used to calculate the relative humidity.
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Evaporation will take place when the humidity is below 100% and the air begins to
absorb water. Any given volume of air can hold a certain amount of water vapor and
the degree of absorption will depend on the amount it is already holding. The term
humidity describes how much water is already in the air; relative to the amount it is
capable of holding. Air is saturated when it cannot hold any more water. Imagine it as a
sponge, if the sponge held half as much water as it was capable of holding, it would be
50% saturated. In the case of air, we would describe the Relative Humidity as being
50%.Energy is required to change water from liquid to vapor. This energy is obtained in
an adiabatic process from the air itself. Air entering an evaporative air cooler gives up
heat energy to evaporate water. During this process, the dry bulb temperature of the air
passing through the cooler is lowered.
In this direct evaporative cooling system designed by me, there is a switch that can on
and off the water pump inside. Firstly we have to on that to make the cooling pads
weight. Than we have to on the fan, which will force to come the air through the
weighted cooling pads. As it passes through the pad the air is cooled by evaporation.
The key to effective evaporative cooling is ensuring that each of the cooling pads are
completely saturated at all times during operation and that the systems fan & motor are
sized and designed to deliver the appropriate airflow for the home. There a speed
control option is also there, where we can control the flow of air. There is an option with
LED lighting system. The system can be charge both solar panel and ac existing source.
Calculations:
Here load voltage is 12V and the total wattage is (10+12+2) W = 22 W.
Minimum run time needed = 4 hours
Ah required by load = ((22*4)/12) Ah = 7.33 Ah
Battery capacity is 12V, 7.5 Ah
Time need to charge only by solar ((7.5*16)/8) = 15 hours.
Combination of external sources and solar panel will reduce the charging time.
(All assumptions are made neglecting all losses)
Cooling fan for Kiosk Stall

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CHAPTER 7
3D DESIGN AND FINAL PRODUCT
Fig.14 3D design of the cooler
Fig.15 Solar evaporative cooler with LED
Cooling fan for Kiosk Stall

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CHAPTER 8
TEST RESULT AND ANALYSIS
 Measuring instrument used:
Fig.16 Thermocouple based thermometer and Digital anemometer[7]
 There are two options for the dc fan speed is given bellow.
Options Speed of air (m/s)
High button 3.90
Low button 3.00
Table.4: Air speed measurement
 As I have tested it, I got those results given bellow in the high speed option in
between 2:00 PM to 2:30 PM on 19/05/2016 in Chennai.
S. No. Actual
RH
(%)
Increased
RH
(%)
RH
Increment
(%)
Actual
Temperature
(0
C)
Reduced
temperature
(0
C)
Temperature
reduction
(0
C)
1 48.00 58.50 10.50 33.50 29.60 3.90
2 49.50 57.50 8.00 33.00 29.40 3.60
3 50.00 59.00 9.00 33.10 29.30 3.80
4 51.00 59.50 8.50 32.70 29.10 3.60
5 51.50 58.00 6.50 32.80 29.40 3.40
Total
avg.
8.50 3.66
Table.5: Temperature and Humidity measurement
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Conclusion:
So finally the product that I have made will run by both solar and existing power
supply which will resolve the power issue and it can give both light and cooling effect
to those persons. As I have tested this in Chennai, having higher humidity, it will work
more efficiently in low humidity areas.
References:
[1] http://www.alamy.com/stock-photo/orissa.html
[2] http://www.westcountyheatandcool.com
[3] http://www.nairaland.com/1508281/lg-introduces-new-mosquito-combating-air
[4] http://www.portacool.com/en/us/home
[5] http://evaporative-cooling24.co.uk/evaporative-coolers
[6] http://www.switch-lighting.co.nz
[7] http://www.amprobe.com/amprobe/usen/hvac-tools
[8] http://www.sciencedirect.com/science/article/pii/S1359431102000698
Cooling fan for Kiosk Stall