Thermal Performance and Energy Balance (1) - 1

THERMAL PERFORMANCE AND ENERGY BALANCE OF FOOD COOKING USING
SELECTED POT TYPES AND SIZES
BY
ADENIYI ADEMOLA JOHNSON
EES/17/18/0057
AKINTOLA ABIDEEN ISOLA
EES/17/18/0105
OLADUNJOYE EMMANUEL ABIODUN
EES/17/18/0322
A PROJECT SUBMITTED TO THE DEPARTMENT OF AGRICULTURAL ENGINEERING,
FACULTY OF ENGINEERING, COLLEGE OF ENGINEERING AND ENVIRONMENTAL
STUDIES
IN PARTIAL FUFILMENT OF REQUIREMENTS FOR THE AWARD OF BACHELORS
DEGREE IN AGRICULTURAL ENGINEERING, OLABISIONABANJO UNIVERSITY, AGO -
IWOYE, OGUN STATE, NIGERIA.
MAY, 2023.
DECLARATION
We hereby declare that this project has been written by us and a record of our own research work. It
has not been presented in any previous application for a higher degree of this or any other university.
All citations and sources of information are clearly acknowledged by means of reference.
Adeniyi Ademola Johnson ………………………..…..

EES/17/18/0057 Signature/Date
Akintola Abideen Isola …………………………....

Oladunjoye Emmanuel Abiodun ……………………………..

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CERTIFICATION
This project entitled “Thermal performance and energy balance of food cooking using selected pot
types and sizes”, meets the regulation governing the award of the degree of Bachelor of Engineering
of the Olabisi Onabanio University, Ago-Iwoye and is approved for its contributions to Engineering
Knowledge and literary presentation.
………………………….. …………………………..
Engr. Adetifa B.O. Date
Project Supervisor
………………………….. …………………………..
Engr. Babalola A.A. Date
Ag. Head of Department
II
DEDICATION
This project is dedicated to almighty God, the creator of the universe and the owner of the breath,
whose mercy and omnipotence made this work a reality.
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ACKNOWLEDGEMENT
Our profound gratitude goes to almighty God for guiding us through this study.
We would like to express our sincere gratitude and appreciation to all those who have contributed to
the successful completion of this project.
First and foremost, we would like to extend our deepest thanks to my project supervisor, Engr. B.O.
Adetifa, for their invaluable guidance, support, and expertise throughout the duration of this project.
His insightful feedback, constructive criticism, and constant encouragement have been instrumental
in shaping the direction and quality of this work. We would also like to acknowledge the
contributions of the faculty members of the Agricultural Engineering department at Olabisi
Onabanjo University for their support and encouragement throughout my academic journey. Their
dedication to teaching and research has been a constant source of inspiration.
We extend our heartfelt appreciation to our classmates and friends who provided assistance and
encouragement during the project's execution. Their willingness to collaborate, share ideas, and
engage in fruitful discussions greatly enriched the project's outcomes. We would like to express our
gratitude to the participants and individuals who generously shared their time, knowledge, and
expertise to support the data collection process. Their contributions were invaluable in providing the
necessary insights and perspectives for this research.
We would like to acknowledge the support and resources provided by Department of Agricultural
Engineering, Olabisi Onabanjo University during the course of this project. Their cooperation and
willingness to provide access to facilities, equipment, and materials were essential in carrying out
the experiments and analysis.
Finally, we would like to express our heartfelt appreciation to our families for their unwavering
support, love, and encouragement. Their belief in our abilities and their constant motivation has been
the driving force behind our accomplishments. Although it is not possible to name everyone who has
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contributed to this project, we want to express our gratitude to all those who have played a role,
either big or small.
Thank you all for being a part of this journey and for making this project possible.
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TABLE OF CONTENTS
DECLARATION....................................................................................................................................I
CERTIFICATION.................................................................................................................................II
DEDICATION.....................................................................................................................................III
ACKNOWLEDGEMENT...................................................................................................................IV
TABLE OF CONTENTS.....................................................................................................................VI
LIST OF FIGURES..........................................................................................................................VIII
LIST OF PLATES.................................................................................................................................X
LIST OF TABLES...............................................................................................................................XI
LIST OF NOMENCLATURES.........................................................................................................XII
ABSTRACT.....................................................................................................................................XIV
CHAPTER ONE....................................................................................................................................1
INTRODUCTION.............................................................................................................................1
1.1 General Background................................................................................................................1
1.2 Problem Statement...................................................................................................................2
1.3 Aim and Objectives..................................................................................................................3
1.4 Justification..............................................................................................................................3
1.5 Scope........................................................................................................................................3
CHAPTER TWO...................................................................................................................................4
LITERATURE REVIEW...................................................................................................................4
2.1 Cooking....................................................................................................................................4
2.2 Pot Sizes and Cooking Efficiency...........................................................................................4
2.3 Energy Balance and Efficiency................................................................................................5
2.4 Cooking Heat Transfer.............................................................................................................5
2.5 Boiling and evaporation...........................................................................................................5
2.6 Heat Transfer and Cooking Time.............................................................................................6
2.6.1 Modes of Heat Transfer........................................................................................................6
2.7 Types of Pot.............................................................................................................................7
2.7.1 Properties of clay pot..........................................................................................................10
2.7.2 Advantages of clay pot........................................................................................................11
2.8 Characteristics of Quality Cookware.....................................................................................11
VI
2.8.1 Good conductivity...............................................................................................................11
2.8.2 Uniform heat distribution...................................................................................................12
2.8.3 Proper thickness/Gauge......................................................................................................12
CHAPTER THREE.............................................................................................................................13
METHODOLOGY..............................................................................................................................13
3.1 Materials................................................................................................................................13
3.2 Experimental Procedures for Water Heating Test..................................................................17
3.3 Experimental Procedures for Cooking Test...........................................................................19
3.4 Experimental Setup................................................................................................................20
3.5Experimental Analysis............................................................................................................22
3.5.1Temperature Distribution and Heat Energy Used................................................................22
3.5.2 Cooking Efficiency.............................................................................................................24
3.5.3 Total Heat Supply...............................................................................................................24
3.5.4 Cooking Power...................................................................................................................25
3.5.5 Thermal Efficiency.............................................................................................................25
3.5.6 Energy Balance...................................................................................................................25
3.5.7 Unaccountable Losses........................................................................................................26
3.6 Statistical analysis..................................................................................................................26
CHAPTER FOUR...............................................................................................................................27
RESULTS AND DISCUSSION..........................................................................................................27
4.1 Water Heating Test Results....................................................................................................27
4.2 Food Temperature Distribution..............................................................................................39
4.3 Cooking Power and Cooking Efficiency...............................................................................51
4.4. ENERGY BALANCE..........................................................................................................62
4.5. COMPARATIVE ANALYSIS..............................................................................................64
CHAPTER FIVE.................................................................................................................................70
CONCLUSION AND RECOMMENDATION...................................................................................70
5.1 Conclusion.............................................................................................................................70
5.2 Recommendation...................................................................................................................70
References........................................................................................................................................72
VII
LIST OF FIGURES
Figure 4.1: 1 kg of water heating test for different small sized pots………………………...28
Figure 4.4: 1 kg of water heating test for different medium sized pots………...…………....32
Figure 4.5: 2 kg of water heating test for different medium sized pots ………………..……33
Figure 4.6: 3 kg of water heating test for different medium sized pots……………………...35
Figure 4.7: 1 kg of water heating test for different big sized pots……………………….......36
Figure 4.8: 2 kg of water heating test for different big sized pots ………………………......37
Figure 4.9: 3 kg of water heating test for different big sized pots……………………….......39
Figure 4.10: Temperature distribution for different small sized pots with rice of 85 g……...40
Figure 4.11: Temperature distribution for different small sized pots with rice of 170 g…….41
Figure 4.12: Temperature distribution for different small sized pots with rice of 250 g…….43
Figure 4.13: Temperature distribution for different medium sized pots with rice of 85 g…...44
Figure 4.14: Temperature distribution for different medium sized pots with rice of 170 g….45
Figure 4.15: Temperature distribution for different medium sized pots with rice of 250 g….47
Figure 4.16: Temperature distribution for different big sized pots with rice of 85 g………...48
Figure 4.17: Temperature distribution for different big pots sizes with rice of 170 g……….49
Figure 4.18: Temperature distribution for different big pots sizes with rice of 250 g……….51
Figure 4.19: Cooking Power for different small sized pots with 1 kg of water quantity…….52
Figure 4.20: Cooking Power for different small size pots with 2 kg of water quantity……...53
Figure 4.21: Cooking Power for different small size pots with 3 kg of water quantity……...54
Figure 4.22: Cooking Power for different medium size pots with 1 kg of water quantity…..56
VIII
Figure 4.25: Cooking Power for different big size pots with 1 kg of water quantity………..59
IX
LIST OF PLATES
Plate 2.1: Iron Pot ……………………………………………………………………...……8
Plate 2.2: Stainless Pot ……………………………………………………………………....8
Plate 2.3: Aluminium Pot ……………………………………………………………….…...9
Plate 2.4: Clay Pot ………………………………………………………………………….10
Plate 3.1 Digital Temperature Logger (4 Channels) with Four k –Type Thermocouples...…16
Plate 3.2: Digital Electronic Weighing Balance …………………………………………....16
Plate 3.3: Digital Hygrometer ……………………………………………………………....17
Plate 3.4: Experimental setup for Aluminium pot of different sizes ………………………..20
Plate 3.5: Experimental setup for Stainless pot of different sizes …………………………..20
Plate 3.6: Experimental setup for Iron pot of different sizes ……………………………..…21
Plate 3.7: Experimental setup for Clay pot of different sizes ……………………………….21
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LIST OF TABLES
Table 3.1 Aluminum pots specification ………………………....13
Table 3.2 Stainless pots specification ……………………….......13
Table 3.3 Stainless pots specification …………………………...14
Table 3.4 Clay pots specification……………………………..….14
Table 3.5 Energy balance ………………………………………..63
Table 3.6 Comparative analysis …………………………………64
Table 3.7 Comparative analysis …………………………………66

Table 3.8 Comparative analysis …………………………............68
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LIST OF NOMENCLATURES
Parameters Meaning Unit
Quantity of heat transferred to water j
Quantity of heat transferred to pot j
Quantity of heat transferred to wall j
Mass of water kg
Specific heat capacity of pot j/kg0c
Mass of pot kg
Change in pot temperature C
Change in wall temperature C
Mass of wall kg
Mass of air kg
Specific heat capacity of water j/kg0c
Specific heat capacity of air j/kg0c
Change in air temperature C
Volume of air m 3
Length of kitchen m
Breadth of kitchen m
Height of kitchen m
Thermal efficiency %
XII
Initial water temperature C
Change in water temperature C
Mass of gas used by minute g
Initial mass of water Kg
Density of air at room temperature kg/m3
Total amount of heat transferred j
Calorific value of cooking gas kj/g0c
Cooking power W
Time Minutes
Energy accountable j
Energy utilized j
ABSTRACT
The thermal performance and energy balance of cooking using selected cook pots were
investigated in this study. The aim of this study is to determine the thermal performance and energy
balance of food cooking using selected cook pots. The objective is to study the temperature
distribution of selected pot types and their contents during and after cooking. Four pot types were
selected for the experiment: aluminum, stainless, iron and clay.
Three different quantities of rice 85 g, 170 g and 250 g were used for the cooking test and three
quantities of water 1 kg, 2 kg and 3 kg were used for water heating test using a standard cooking
setup. Energy balance calculations were conducted to assess the overall energy utilization, cooking
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power and cooking efficiency of each cook pot. Energy balance calculations were conducted using
MS Excel and SPSS to carry out comparative analysis.
The results revealed significant variations in the thermal performance of the cook pots. The Iron
pot exhibited higher heat retention, leading to extended cooking durations even after the heat source
was turned off. The aluminum pot was identified as the most energy-efficient option, whereas the
clay pot offered faster heat transfer but consumed more energy and exhibited prolonged cooking
times. The stainless pot provided a balance between energy efficiency and heat retention.
Further research could focus on experimenting on different food types, effects of pot shapes and
other heating source to provide a comprehensive understanding of cook pot selection for optimal
cooking experiences.
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CHAPTER ONE
INTRODUCTION
1.1 General Background
Thermal performance of food cooking is the combination of temperature and time required to
eliminate a desired number of microorganisms from a food product. Thermal properties are involved
in almost every food processing operation. The most important thermal properties in food processing
such as, specific heat capacity, thermal conductivity, and thermal diffusivity of food materials depend
mostly on the food’s composition, temperature and density. They have a significant effect on the rate
of heat transfer into the particulates within the food product. When considering heat transfer during
food processing, the thermal conductivity of the food plays an important role. The thermal
conductivity of food determines how fast heat can be evenly transferred to the entire food mass,
which in turn affects the quality of the final product.
Cooking is an inevitable part of daily life for many reasons such as to reduce food borne
illnesses, and to enhance taste, texture, and digestibility. Food is cooked using thermal energy. The
energy is heat. Depending on the cooking appliance, it can either be electrical or chemical potential
energy and the electric potential energy is converted to thermal energy by electric cooker. Pots and
utensils used for cooking and food preparation typically work on Liquefied petroleum gas (LPG),
coal, biomass, or electric stoves. Liquefied petroleum gas LPG gas is the most used energy source.
Kitchens are one of the places where deals with this phenomenon daily in cookware application
(Paisarn N., 2014).
Cooking, ultimately, is about heat, how heat enters the food and what happens to the food
when it enters. In cooking, typically there is a heating element (such as a fire), a heat transfer
medium (oil, water, air, a pan or pot), and the food itself. The heat moves from the element through
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the medium to the food (Burr Z., 2022). The heat moves from the element through the medium to the
food.
'Temperature' and 'heat' are often used interchangeably, but they are not the same thing.
Temperature is the driving force for heat transfer. Like gravity moves masses, temperature moves
heat. Heat moves from hotter materials to colder materials (a temperature difference causes the heat
to move). Temperature measures, roughly speaking, how much the molecules in a material are
vibrating. Temperature is a property of a material independent of how much of a material there is.
Heat or thermal energy, is a measure of the amount of energy that is contained in a material (this is a
bit simplified - there are lots of different measures and forms of energy).
Heat depends on how much of the material you have, you double the amount of a material,
and you double the heat. Thermal performance is a basic tool that assesses how efficiently a stove
uses fuel to heat water in a cooking pot and amount of emissions created as a result. The ratio of heat
energy entering the cooking pot to the energy content of the fuel consumed is known as the thermal
efficiency of cook stove.
1.2 Problem Statement
The thermal performance and energy balance of food cooking using selected pot types and
sizes pose a significant problem in achieving energy-efficient and sustainable cooking practices.
Despite the widespread use of various pot materials and sizes, there is a lack of comprehensive
understanding regarding their thermal properties and their impact on heat transfer, cooking times,
and energy utilization. This knowledge gap hinders the ability to make informed decisions in
selecting appropriate pots for efficient cooking and optimal energy utilization. By gaining a deeper
understanding of the thermal performance and energy balance of food cooking using selected pot
types and sizes, it will be possible to provide evidence-based recommendations, guidelines, and
strategies for selecting pots that optimize heat transfer, cooking times, and energy utilization.
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1.3 Aim and Objectives
The aim of this study is to determine the thermal performance and energy balance of food
cooking using selected cook pots. The specific objectives include to;
I. To study the temperature distribution of selected pot types and their contents during and after
cooking.
II. To investigate the energy balance, cooking efficiency and cooking power for selected pot types
and sizes heating different quantities of water.
III. To carry out a comparative analysis to determine the effect of pot type and size on different
cooking parameters.
1.4 Justification
The justification for studying the thermal performance and energy balance of food cooking
using selected pot types and sizes lies in promoting energy efficiency, resource conservation,
optimizing cooking times, raising consumer awareness, and driving advancements in the culinary
industry. By understanding the thermal properties of different pots, we can make informed decisions
that result in more sustainable and efficient cooking practices, benefiting both individuals and the
environment.
1.5 Scope
This study is based on thermal performance and energy balance of food cooking using
different cook pots, (Iron, Stainless & aluminum) of different sizes.
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CHAPTER TWO
LITERATURE REVIEW
2.1 Cooking
Cooking is a fundamental activity that requires efficient heat transfer and energy utilization to
achieve desirable outcomes. The thermal performance and energy balance of food cooking,
particularly when considering the pot types and sizes used have significant implications for energy
efficiency and cooking effectiveness. This literature review aims to examine existing research on
cooking, focusing on the thermal performance and energy balance associated with selected pot types
and sizes, highlighting key findings and their implications for energy-efficient cooking practices.
The reason for cooking include;
1. To improve its digestibility, that is, to make it easier to eat, break down and absorb,
2. To increase its palatability, which means to make it more attractive by improving the taste,
smell and colour, and
3. To make it safe to eat, in relation to food poisoning and food spoilage micro-organisms.
2.2 Pot Sizes and Cooking Efficiency
The size of the pot relative to the amount of food being cooked plays a crucial role in thermal
performance and energy balance. Oversized pots can result in increased energy consumption due to
higher heat loss to the surroundings (Liu et al., 2020). Conversely, using an undersized pot may lead
to uneven cooking and longer cooking times (Sarkar et al., 2018). Therefore, selecting an
appropriately sized pot is essential for optimizing cooking efficiency and energy utilization.
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2.3 Energy Balance and Efficiency
Numerous studies have examined the energy balance and efficiency of various pot types and
sizes during cooking. Ogunlowo et al. (2017) conducted experiments comparing aluminum and
stainless steel pots of different sizes. They found that smaller pots exhibited higher energy efficiency
due to reduced heat loss. However, larger pots had shorter cooking times due to increased heat
transfer. Adeosun et al. (2020) investigated the energy balance of cast iron pots and observed that
although they consumed more energy, their heat retention properties minimized the need for
extended heating during cooking.
2.4 Cooking Heat Transfer
Cooking of food usually uses a combination of three methods. Leland (2015) explains that
cooking food using conduction involves direct heat transfer through contact with a metal pan, liquid,
or surrounding air. According to Özisik (2012), convection heat transfer occurs faster than
conduction and is facilitated by the movement of air, liquid, or steam around the food during
cooking. Bird et al. (2007) discuss that stirring a pan during cooking redistributes heat through
convection, ensuring even cooking by moving hot parts of the food to cooler regions. As explained
by Holman (2010), heat transfer inside a pot of water is primarily accomplished by convection.
Hotter water rises and transfers heat to other regions, while colder water sinks to the bottom.
2.5 Boiling and evaporation
According to Çengel and Boles (2014), boiling and evaporation both involve the phase
change from liquid to vapor, but they differ in that evaporation occurs at the liquid-vapor interface
without bubble formation, while boiling is characterized by the rapid motion of vapor bubbles
forming at the solid-liquid interface.
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Serway and Jewett (2017) explain that radiation heat transfer in microwave cooking occurs
when microwave (light waves) or infrared energy (heat waves) penetrate the food, causing molecules
of water and fat to vibrate rapidly, generating friction and heat that cooks the food.
2.6 Heat Transfer and Cooking Time
The efficiency of heat transfer directly impacts cooking times and energy consumption.
Research has demonstrated that the thermal conductivity of the pot material significantly influences
heat transfer efficiency (Dehkordi et al., 2019). Aluminum pots, with their high thermal conductivity,
promote rapid and uniform heat distribution, resulting in shorter cooking times (Chiew et al., 2021).
In contrast, stainless steel pots, despite lower thermal conductivity, exhibit better heat retention,
reduce the need for continuous heating and contributing to overall energy efficiency (Ogunlowo et
al., 2017). Clay pots excel in heat retention but it requires longer preheating times and consumes
more energy.
2.6.1 Modes of Heat Transfer
The three fundamental modes of heat transfer are: conduction, radiation and convection.
I. Conduction: According to Çengel and Boles (2014), conduction is the transfer of heat
between substances that are in direct contact with each other. It occurs when heated particles
gain energy and transfer it to nearby particles through direct contact, leading to the passage
of heat from the hot end to the colder end of the substance.
II. Convection: Pulkit Agarwal et al. (2015) explain that convection occurs when warmer areas
of a liquid or gas rise to cooler areas, resulting in a continuous circulation pattern.
Convection ovens use fans to enhance convective heat transfer and circulate hot air for more
efficient cooking.
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III. Radiation: According to Serway and Jewett (2017), radiation is a method of heat transfer
that does not require any physical contact between the heat source and the heated object. It
involves transmitting heat through empty space via thermal radiation, such as infrared
radiation emitted by the sun or a light bulb filament.
2.7 Types of Pot
Different pot types and materials have varying thermal properties, which affect heat transfer and
energy utilization during cooking. Common pot materials include aluminum, stainless steel, iron,
and clay. Studies have shown that aluminum pots have high thermal conductivity, allowing for
efficient heat distribution and shorter cooking times (Dehkordi et al., 2019). Stainless steel pots,
although lower in thermal conductivity, offer good heat retention properties, leading to more even
cooking and reduced energy consumption (Ogunlowo et al., 2017). Cast iron pots are known for
their excellent heat retention, but they may require longer preheating times and consume more
energy (Adeosun et al., 2020).
1. Iron Pot
Iron cookware is a classic. It is strong, inexpensive, and an even conductor of heat. Cooking
with iron pot provides a source of iron, which is an important nutrient. Cooking foods in unglazed
cast iron may double the amount of iron in foods. Iron cookware as shown in Plate 2.1 requires
special handling to prevent rust damage. Frequently coat the inside of cast iron cookware with
unsalted cooking oil, do not scour or wash with strong detergents.
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Plate 2.1: Iron Pot (Yaoota. 2023).
2. Stainless Pot
Stainless pots are widely used in food contact applications. This is largely because of the
corrosion resistance of stainless steels coupled with their strength and durability, their ability to be
readily cleaned and sterilized without deterioration using a wide range of cleaning/sterilizing
systems, and the fact that they impart neither color nor flavor to foodstuffs and beverages.
Serway and Jewett (2017) explain that stainless pots are a combination of iron and other
metals, such as chromium, nickel, molybdenum, or titanium, which contribute to their hardness,
resistance to damage at high temperatures, scratching, and corrosion. According to McGee (2004),
stainless steel as shown in Plate 2.2 is regarded as a durable cookware choice because it will not
permanently corrode or tarnish and its hard, nonporous surface is resistant to wear. Ricketts et al.
(2018) mention that stainless steel cookware does not conduct heat evenly, and it is commonly
constructed with copper or aluminum bottoms to improve heat distribution.
Plat
e 2.2: Stainless Pot (Le Creuset. 2023).
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3. Aluminum Pot
Callister and Rethwisch (2014) explain that aluminum is the third most abundant element in
the Earth's crust and is widespread in minerals. Due to its reactive nature, pure aluminum does not
occur in nature in a free element state. It has good working and forming properties, high ductility,
but low mechanical strength, which is why it is often used in alloys. According to Geankoplis and
Brater (2003), more than half of all cookware sold today is made of aluminum. Aluminum cookware
as shown in Plate 2.3 is often coated with nonstick finishes or treated to harden the surface and make
it more scratch resistant. Helfferich (1962) mentions that the acid in some foods may cause more
aluminum than usual to enter the food when using aluminum cookware, which can lead to pitting on
the pot's surface.
Geankoplis and Brater (2003) explain that anodized aluminum has been processed to harden
the cookware surface, creating a nonstick, scratch-resistant, and easy-to-clean product. The anodized
surface prevents reactions with acidic foods, and manufacturers claim that the aluminum is sealed
during the final stage of anodization to prevent leaching of aluminum into food. Serway and Jewett
(2017) mention that aluminum is a lightweight material, making pots and pans easy to handle. The
U.S. Department of Agriculture (USDA) advises against storing highly acidic or salty foods in
aluminum pots and pans due to potential reactions that may occur. They also caution that thin-walled
aluminum pots and pans can easily get dents, scratches, and become deformed.
Plate 2.3: Aluminium Pot (Yaoota. 2023).
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4. Clay Pot
Clay pots as shown in Plate 2.4 are made from clay soil. This is rich old traditional
knowledge passed from generation to generation. However, this culture of life is in very much longer
of dying a natural death because of modernization. The use of clay item has been in use for long
time.
Plate 2.4: Clay Pot
2.7.1 Properties of clay pot
• Plasticity: we can’t begin to make pottery without it. To be usable, clay has to have the
ability to hold its form while at the same time be pliable enough to be moved by the potter’s
hands. This is plasticity, and it is determined by the size and shape of very fine grains or
particles of clay called platelets.
• Porosity:is the second necessary property that clay must have. Clay has to dry without
cracking. Remember, some clay is too plastic, like bentonite. The platelets are too fine and
smooth and closely squeezes together to let the water of plasticity evaporate without cracking
the pot.
• Vitrification: is the third important property of clay. Vitrification is the process of becoming
glasslike. Although clay products never become absolutely vitrified or glasslike, it is
necessary that the clay become hard (or almost vitrified) at a reasonable temperature. Any
substance will melt at some temperature. Most materials tend to become soft and deform
before they melt. The ability of clay to hold its shape and not sag or slump in the primary
melting stages sets it apart from other materials. Vitrification is not less important than
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plasticity or porosity. It is mentioned last only because it is the last stage in pottery
construction.
2.7.2 Advantages of clay pot
• Availability and cost: clay pots are easily available and very cheap compared to others and
also more environmentally friendly. The cheapest and most durable of all the traditional pot is
the clay pot.
• Clay pot can be re-used: we can use the old discarded broken clay pots for production of
new one.
• Durability: Clay pots last long unless they are purposely or accidentally broken. They can
last as long as one can think. It is a better option with less financial investment.
2.8 Characteristics of Quality Cookware
2.8.1 Good conductivity
To work effectively, cookware should be made of a material that conducts heat quickly and
evenly. Many believe a material’s ability to conduct heat quickly is one of the most important
considerations in choosing cookware.
Aluminum is considered a fast conductor of heat. Its conductivity is four times that of iron or
steel. Aluminum cookware is made by stamping, drawing, or casting and comes in a variety of
gauges (thin, medium, and thick). Iron pots have been around for a long time. Iron is heavy, brittle,
and rusts unless protected. It is a slow conductor of heat. However, once heated, it tends to retain
heat evenly for some time after the heat source is turned off.
Stainless cookware is iron with carbon dissolved in it. It is lighter and stronger than iron but
still rusts. Stainless is an uneven conductor of heat. Stainless steel cookware is created by adding
chromium and nickel to steel. Stainless steel will not rust. Generally, stainless steel cookware is not
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magnetic unless some magnetic material has been added during production. While stainless steel is
easy to clean, durable, and resistant to corrosion, it can warp and develop hot spots.
2.8.2 Uniform heat distribution
Generally, a thin bottom conducts heat quickly but unevenly. In contrast, a thick bottomed
cooking utensil conducts heat slower, but more evenly, reducing hot spots. The thicker the bottom
material, the more heat retained, and the greater the possibility of even cooking performance.
2.8.3 Proper thickness/Gauge
Along with the conductivity of the materials used in the cookware, the gauge or thickness of
the material is another feature that determines the quality of cookware and cooking performance.
When looking at the gauge or weight of a cooking utensil, the thickness of its bottom is most
important.
CHAPTER THREE
METHODOLOGY
3.1 Materials
The materials used in this study include:
1. Aluminum pot: The specific heat capacity of Aluminium is 902 j/kg 0C (Glow Blogs, n.d.) and
the specifications are shown in Table 3.1 below.
Table 3.1: Aluminum pots specification

Pot sizes Length Diameter Pot weight
Small size 0.1 m 0.18 m 0.2839 Kg

Medium
0.09 m 0.21 m 0.295 Kg
size
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Big size 0.11 m 0.26 m 0.41 Kg
2. Stainless pot: The specific heat capacity of stainless is 468 j/kg 0C (The Engineering Mindset,
2016) and the specifications are shown in Table 3.2 below.
Table 3.2: Stainless pots specification

Pot
Pot sizes Length Diameter
weight
Small size 0.09 m 0.06 m 0.455 kg
Medium
0.09 m 0.08 m 0.555 kg
size
Big size 0.1 m 0.22 m 0.705 kg
3. Iron pot: The specific heat capacity of Iron is 449 j/kg 0C (The Engineering Toolbox, 2003) and
Table 3.3: Stainless pots specification

Small size 0.08 m 0.21 m 0.495 kg

Medium
0.1 m 0.26 m 0.85 kg
size
Big size 0.13 m 0.28 m 1.05 kg
4. Clay pot: The specific heat capacity of Clay is 878 j/kg 0C (The Engineering Mindset, 2016) and
Table 3.4: Clay pots specification
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Small size 0.07 m 0.085 m 0.69 kg

Medium
0.08 m 0.2 m 1.23 kg
size
Big size 0.11 m 0.25 m 1.77 kg
5. Water (1, 2 and 3 kg)
6. Rice (85 g, 170 g and 250 g)
The equipment used includes:
1. Gas Cooker: A gas cooker or a gas stove, is a kitchen appliance designed for cooking food using
natural gas or liquefied petroleum gas (LPG) as a fuel source. It was used as the heating source
throughout the experiment.
2. Digital Temperature Logger (4 Channels) with Four k –Type Thermocouples: This device as
shown in Plate 3.1 was used to monitor and record temperature data from multiple points
simultaneously. The points are:
i. Food Temperature
ii. Pot Temperature
iii. Wall Temperature
iv. Kitchen Temperature
Key features of a digital temperature logger with four channels and four K-type thermocouples
include:
i. Dual Type K thermocouple inputs
ii. Large display with backlight
iii. Max/Min/Avg reading recording function
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iv. Data hold function
v. Temperature unit 0C, 0F, K switchable
vi. Auto power off setup
vii. Low battery indicator
Specifications:
Temperature range (T1-T4): - 50 to 1350 0C; - 58 to 2462 0F
Operation temperature: 0 to 50 0C (32 to 122 0F)
Operation humidity: 10 to 90% RH
Storage temperature: -10 to 60 0C (14 to 140 0F)
Storage humidity: 10 to 75% RH
Power supply: 9 V
Dimension: 260 x 55 x 35 mm
Weight: 190 g (battery, four thermocouples included)
Plate 3.1: Digital Temperature Logger (4 Channels) with Four k –Type Thermocouples
15
3. Digital Electronic Weighing Balance: A digital electronic weighing balance as shown in Plate
3.2 is a precision instrument which was used to weigh the mass of empty pot, rice, water and gas
cooker.
Plate 3.2: Digital Electronic Weighing Balance
4. Digital Hygrometer: This device was used to measure and monitor the relative humidity (RH) in
the air in the cooking space (kitchen). As shown in Plate 3.3, it feature digital displays that
provide direct readings of relative humidity and offer high accuracy, quick response, and
additional features such as temperature measurement, time and alarm clock. The humidity
measuring range is 10% to 99% RH.
16
Plate 3.3: Digital Hygrometer
5. Stopwatch or Timer: This enabled us to gather important data regarding heating times, cooking
durations, and cooking efficiency. The data was recorded at 1 minute intervals throughout the
experiment.
3.2 Experimental Procedures for Water Heating Test
The following experimental procedures for water heating test were carried out for each cook pot:
Step 1: The four K type thermocouples were connected to the temperature logger device using the
connecting cables. Each thermocouple was connected to a different channel of the logger.
Step 2: Initially, the quantity of cooking gas was weighed; weight of empty cooking pot and the
required mass of water was measured.
Step 3: The required cook pot was filled with the required mass of water and then placed on the
cooking gas.
Step 4: One thermocouple was placed inside the pot filled with water, one at the side of the pot, one
at the kitchen wall near the pot, and one in the ambient air in the cooking space (kitchen).
Step 5: The thermometer was turned on and the measurement unit (Celsius) was selected on it.
Step 6: The initial temperature for water, pot, wall, kitchen and humidity were recorded.
Step 7: The heat source (gas cooker) was turned on as well as the stopwatch to track the heating
duration and monitor the heating process.
Step 8: Temperature of the water was recorded at 1 minute intervals until the water reached boiling
point.
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Step 9: Once the water reached boiling point, the gas cooker was turned off and the time taken was
noted.
Step 10: The temperature distribution was continuously taken for up to 5 minutes after the gas was
turned off before the thermocouples were removed from the water and pot body.
Step 11: The gas was weighed at the end of the heating process to determine the quantity of gas used
for the heating.
Step 12: Temperature distributions results were graphed and necessary calculations were done for
each of the cook pots, based on the temperature data obtained and were represented in graphical
form.
Step 13: Finally, statistical analysis was performed on the recorded data to compare the thermal
performance and energy balance of the cook pots. The data was used to make recommendations on
the type of cook pots that are most suitable for cooking.
3.3 Experimental Procedures for Cooking Test
The following experimental procedure for cooking test was carried out for each cook pot:
Step 1: The four K type thermocouples were connected to the temperature logger device using the
connecting cables.
Step 2: Initially, the quantity of cooking gas was weighed; weight of empty cooking pot and the
required mass of rice was measured.
Step 3: The required cook pot was filled with the required mass of rice with water and then placed
on the cooking gas.
Step 4: One thermocouple was placed inside the pot filled with rice and water, one at the side of the
pot, one at the kitchen wall near the pot, and one in the ambient air in the cooking space (kitchen).
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Step 5: The thermometer was turned on and the measurement unit (Celsius) was selected on it.
Step 6: The heat source (gas cooker) was turned on as well as the stopwatch to track the cooking
time and monitor the cooking process.
Step 7: Temperature of the rice was recorded at 1 minute intervals till it was cooked.
Step 8: After the rice was cooked, the gas cooker was turned off and the time cooked was recorded.
Step 9: The temperature distribution was continuously recorded for 10-15 minutes after the gas was
turned off before interruption of the thermocouples from the rice and pot body.
Step 10: The gas was weighed at the end of the rice cooking to determine the quantity of gas used.
Step 11: Temperature distributions results were graphed and necessary calculations were done for
each of the cook pots, based on the temperature data obtained and were represented in graphical
form.
Step 12: Finally, statistical analysis was performed on the recorded data to compare the thermal
performance and energy balance of the cook pots. The data was used to make recommendations on
the type of cook pots that are most suitable for cooking.
3.4 Experimental Setup
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Plate 3.4: Experimental setup for Aluminium pot of different sizes (Small, medium and big).
Plate 3.5: Experimental setup for Stainless pot of different sizes (Small, medium and big).
Plate 3.6: Experimental setup for Iron pot of different sizes (Small, medium and big).
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Plate 3.7: Experimental setup for Clay pot of different sizes (Small, medium and big).
3.5Experimental Analysis
3.5.1Temperature Distribution and Heat Energy Used
When the experiment was carried out, the heat transferred from the cooking gas to various points
such as the water, pot, kitchen wall and cooking space (kitchen) as stated below in equation 3.1, 3.2,
3.3, 3.4, 3.5 and 3.6 were determined.
i. (3.1)
Where:
= Amount of heat transferred through the pot to the water
= Mass of water
= Specific heat capacity of water (4186 j/kg 0C)
= Change in water temperature
ii. (3.2)
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Where:
is the quantity of heat energy lost to the pot.
is the mass of the pot
is the specific heat capacity of the material (pot) is composed of e.g.
(aluminum,stainless, iron and clay material).
is the change in pot temperature.
iii. (3.3)
Where:
is the quantity of heat energy transferred to the kitchen wall
is the mass of wall (115200 kg)
is the specific heat capacity of brick
is the change in wall temperature.
iv. (3.4)
Where:
is the kitchen temperature
is the mass of air (76.8 kg)
is the specific heat capacity of air (1005 j/kg 0C)
is the change in air temperature.
v. (3.5)
Where:
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is the density of air at room temperature (1.28 kg/m3)
is the mass of air
is the volume of air
vi. (3.6)
Where:
l is the length of the kitchen (1.79 m)
b is the breadth of the kitchen (1.19 m)
h is the height of the kitchen (2.55 m)
Therefore: Volume of air ( ) = 5.43 m3
Room Temperature = 33.5 °C
3.5.2 Cooking Efficiency
The cooking efficiency is the ratio of the heat energy entering the water and the energy supplied by
the cooking gas as stated in equation 3.7...
(3.7)
Where:
is thermal/cooking Efficiency
Specific heat capacity of water at constant pressure
The initial temperature of water
Change in water temperature
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Total amount of heat transferred from gas cooker surface through bottom of the pot to
water
3.5.3 Total Heat Supply
Total heat energy used as stated in equation 3.3 is the amount of energy used in heating the water.
The equation is expressed as:
(3.8)
Where:
is the total energy used in boiling
m is the mass of gas used per minute (g)
is the calorific value of cooking gas = 50 kJ/g
3.5.4 Cooking Power
Cooking power represents the rate at which energy is being transferred to the cooking process and it
is simply represented as equation 3.9;
(3.9)
Where:
= Cooking power
= Amount of heat transferred from the gas through the pot to water
= Time taken
3.5.5 Thermal Efficiency
This is the ratio of cooking power to energy used in cooking as shown below in equation 3.10
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(3.10)
Where:
3.5.6 Energy Balance
Energy balance involves assessing the energy input (heat energy supplied) and energy output
(heat energy transferred to the water and any energy losses) during the cooking process. As
shown in equation 3.11, it is the relationship or balance between the amount of heat energy
transferred to the water, pot, wall and kitchen.
(3.11)
Where:
= Energy accountable
3.5.7 Unaccountable Losses
Energy losses occur during the cooking process and can impact the overall energy balance. This is the
subtraction of energy accountable from total energy used in cooking as shown in equation 3.12
(3.12)
Where:
Unaccountable energy loss or energy utilized
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3.6 Statistical analysis
The Experiment was analyzed with MS Excel to determine the cooking power, cooking efficiency,
energy balance and SPSS to carry out comparative analysis.
CHAPTER FOUR
RESULTS AND DISCUSSION
4.1 Water Heating Test Results
Figure 4.1 shows the results and graphical representation of 1 kg of water heating test result for
small sized pots of different materials. Aluminium pot revealed that the water initial temperature was
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31 °C and that of pot was 30.1 °C. Water reached a maximum temperature of 100.5 °C around the
4th minute. Meanwhile, the pot temperature initially lagged behind but eventually peaked at 106.6
°C around the 3rd minute before gradually decreasing when the gas cooker was turned off. For
Stainless pot, the graph shows that the water and pot temperature started at 34.6 °C and 35.4 °C
respectively. Both temperatures reached a peak of 102 °C and 102.9 °C. The pot temperature
followed the water temperature then gradually decreased when gas was turned off, mirroring the
trend of the water temperature.
For Iron pot, the graph reveals that the water and pot temperature began at 33.3 °C and 34 °C. By the
4th minute, both reached a peak of 101.8 °C and 92.2 °C. When the gas was turned off, the water
temperature gradually decreased but remained relatively stable throughout the experiment. The pot
temperature followed a similar trend as the water temperature. For Clay pot, the initial temperature
of water and pot was 32.6 °C and 32.7 °C respectively. At 7th minute, both water and pot reaches a
peak temperature of 101.9 °C and 127.7 °C. At 8th minute when the gas was turned off the water
temperature reduced to a temperature of 101.4 °C and that of pot sharply reduced to 95.7 °C.
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Figure 4.1: 1 kg of water heating test for different small sized pots
Figure 4.2 shows the graphical representation of 2 kg of water heating test result for small sized pots
of different materials. Aluminium pot initially had a water temperature of 32.8 °C, while the pot
itself was at 34.4 °C. By the 7th minute, both the water and the pot had temperatures of 100.6 °C and
102.1 °C, respectively. After turning off the gas at the 8th minute, the water temperature decreased to
101.6 °C, while the pot temperature dropped to 91.3 °C. Water temperature in the stainless pot
started at a temperature of 36.9 °C, and the pot itself was initially at 37.9 °C. At the 6th minute, both
the water and the pot reached their peak temperatures of 102.8 °C and 108.7 °C, respectively.
Turning off the gas at the 7th minute led to a decrease in the water temperature to 102.2 °C, while
the pot temperature decreased to 96.3 °C.
Water in the Iron pot was initially at a temperature of 35.4 °C, and the pot itself was at 38.8 °C. By
the 7th minute, both the water and the pot reached their peak temperatures of 101.7 °C and 103.3 °C,
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respectively. After turning off the gas at the 8th minute, the water temperature decreased to 97.7 °C,
while the pot temperature dropped to 86.4 °C. Clay pot initial water temperature was 35.1 °C, while
the pot was initially at 44.1 °C. At the 11th minute, both the water and the pot reached their peak
temperatures of 102 °C and 135.1 °C, respectively. Turning off the gas at the 12th minute caused the
water temperature to decrease to 101.7 °C, while the pot temperature sharply dropped to 99.8 °C.
Figure 4.3 shows the graphical representation of 3 kg of water heating test result for small sized pots
of different materials. Water temperature of Aluminium pot at time 0, was 33 °C, and the pot
temperature was 33.5 °C. At time 10, the water temperature reached its peak at 101.5 °C, and the pot
temperature reached 100.6 °C. At time 11, the gas was turned off, and the water temperature dropped
to 97.7 °C, while the pot temperature decreased to 82 °C. At time 0, the water temperature for
Stainless pot was 36.2 °C, and the pot temperature was 37 °C. At time 8, the water temperature
reached its peak at 101.5 °C, and the pot temperature reached 105.2 °C. At time 9, the gas was
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turned off, and the water temperature decreased, reaching 98.1 °C, while the pot temperature
decreased to 90.5 °C.
For Iron pot, at the beginning of the experiment, the water in the iron pot was at a temperature of
36.8 °C, while the pot itself registered 37.2 °C. After 9 minutes, the water reached its maximum
temperature of 101.7 °C, accompanied by the pot's peak temperature of 107.8 °C. At the 10th
minute, the gas supply was ceased, resulting in a decline in the water temperature to 97.3 °C, while
the pot's temperature decreased to 87 °C. For Clay pot, the water had a temperature of 34.3 °C at the
beginning of the experiment, while the pot itself was slightly warmer at 37.9 °C. By the 11th minute,
the water temperature reached its peak value at 100.7 °C, coinciding with the pot temperature
peaking at 132.8 °C. When the gas was turned off at the 12th minute, the water temperature
decreased to 99.6 °C, while the pot temperature experienced a significant drop to 95.1 °C.
30
Figure 4.4 shows the graphical representation of 1 kg of water heating test result for medium sized
pots of different materials. For Aluminium pot, the initial temperature of water and pot was 40.6 °C
and 38.3 °C respectively. At 6th minute, both water and pot reaches a peak temperature of 102.1 °C
and 125.1 °C. At 7th minute when the gas was turned off the water temperature reduced to a
temperature of 100.8 °C and that of pot reduced to 90.1 °C. Initially, the water in the Stainless pot
had a temperature of 34 °C, while the pot itself was slightly warmer at 33.3 °C. By the 4th minute,
the water temperature reached its peak value at 102 °C, while the pot temperature peaked at 116.3
°C. This indicates efficient heat transfer from the burner to the stainless steel pot and the water.
Subsequently, as the gas was turned off, the water temperature decreased to 99.5 °C at the 5th
minute, and the pot temperature dropped to 92.8 °C. This reduction in temperature can be attributed
to the dissipation of heat without further heating.
For Iron pot, initially, the water in the pot had a starting temperature of 32.2 °C, while the pot itself
was at 34.7 °C. By the 5th minute, the water temperature reached a significant milestone, reaching a
value of 102.1 °C, while the pot temperature rose to 92.8 °C. As time went on, the gas was turned
off, leading to a gradual decrease in both the water and pot temperatures. At the start of the
experiment for clay pot, the water temperature was 33 °C, while the pot temperature was slightly
higher at 34.6 °C. By the 5th minute, the water temperature reached 86.1 °C, demonstrating a
significant increase. The pot temperature also rose to 113.5 °C, indicating efficient heat transfer
between the burner and the pot. As the experiment continued, the water temperature peaked at 100.7
°C by the 7th minute, while the pot temperature reached its highest point at 131.8 °C. This showed
that the pot effectively absorbed and retained heat. However, as the gas was turned off, both the
water and pot temperatures began to decrease.
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Figure 4.4: 1 kg of water heating test for different medium sized pots
pots of different materials. When Aluminium pot was used, the initial temperature of water and pot
was 34.7 °C and 38.3 °C respectively. At 6th minute, both water and pot reached a peak temperature
of 101.2 °C and 127.5 °C. At 7th minute when the gas was turned off the water temperature reduced
to a temperature of 98.9 °C and that of pot reduced to 85.3 °C. At the beginning of the experiment
for stainless pot, the water in the pot had a temperature of 36.5 °C, while the pot itself was at 38.5
°C. By the 5th minute, the water temperature reached 91.9 °C, indicating a significant increase. The
pot temperature also climbed to 95.3 °C, demonstrating efficient heat transfer between the heat
source and the pot. However, once the gas was turned off, both the water and pot temperatures began
to decline.
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The initial water temperature when Iron pot was used was 37.5 °C, and the pot temperature was
slightly higher at 38.4 °C. By the 6th minute, the water temperature reached its peak at 100.9 °C,
while the pot temperature peaked at 102.3 °C. This indicates efficient heat transfer and absorption by
the pot. When gas was turned off, both the water and pot temperatures started to decline gradually.
By the end of the 15-minute period, the water temperature decreased to 81.9 °C, and the pot
temperature decreased to 73.4 °C. For Clay pot, the initial water temperature was 35.1 °C, while the
pot temperature started at 38.3 °C. As the experiment progressed, both the water and pot
temperatures increased. When gas was turned off at the 12th minute, the pot temperature sharply
dropped to 70.9 °C, while the water temperature decreased more gradually to 98.1 °C.
pots of different materials. For Aluminium pot, the initial temperature of water and pot was 33.3 °C
33
and 37.7 °C respectively. At 7th minute, both water and pot reaches a peak temperature of 100.2 °C
and 115.6 °C. At 8th minute when the gas was turned off the water temperature reduced to a
temperature of 96.1 °C and that of pot reduced to 112.3 °C. When Stainless pot was used, the initial
temperature of water and pot was 36.6 °C and 38.9 °C respectively. At 10th minute, both water and
pot reaches a temperature of 101.2 °C and 98 °C. At 11th minute when the gas was turned off the
water temperature reduced to a temperature of 98.2 °C and that of pot reduced to 88.5 °C.
For Iron pot, the initial temperature of water and pot was 34 °C and 33.9 °C respectively. At 5th
minute, both water and pot reaches temperature of 104.1 °C and 85.1 °C. At 6th minute when the gas
was turned off the water temperature reduced to a temperature of 99.1 °C and that of pot reduced to
83.7 °C. For Clay pot, the initial temperature of water and pot was 35.8 °C and 43.5 °C respectively.
At 11th minute, both water and pot reaches a peak temperature of 104.1 °C and 101.8 °C. At 12th
minute when the gas was turned off the water temperature reduced to a temperature of
96.6 °C and that of pot reduced to 79.5 °C.
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Figure 4.7 shows the graphical representation of 1 kg of water heating test result for big sized pots of
different materials. For Aluminium pot, the initial temperature of water and pot was 36.1 °C and
33.8 °C respectively. At 3rd minute, both water and pot reaches a temperature of 102.9 °C and 82.2
°C. At 4th minute when the gas was turned off the water temperature reduced to a temperature of
98.3 °C and that of pot reduced to 83.2 °C. For Stainless pot, the initial temperature of water and pot
was 35.1 °C and 35.6 °C respectively. At 4th minute, both water and pot reaches a temperature of
101.5 °C and 90.5 °C. At 5th minute when the gas was turned off the water temperature reduced to a
temperature of 96.7 °C and that of pot reduced to 87.5 °C.
For Iron pot, the initial temperature of water and pot was 32.6 °C and 32.4 °C respectively. At 5th
minute, both water and pot reaches a temperature of 102.1 °C and 90.6 °C. At 6th minute when the
35
gas was turned off the water temperature reduced to a temperature of 97.6 °C and that of pot reduced
to 82 °C. For Clay pot, the initial temperature of water and pot was 31.1 °C and 36.6 °C respectively.
At 7th minute, both water and pot reaches a temperature of 100.4 °C and 127.6 °C. At 8th minute
when the gas was turned off the water temperature reduced to a temperature of 98.9 °C and that of
pot reduced to 97.5 °C.
Figure 4.7: 1 kg of water heating test for different big sized pots
different materials. For Aluminium pot, the initial temperature of water and pot was 37 °C and 36.7
°C respectively. At 5th minute, both water and pot reaches a temperature of 101.6 °C and 96.9 °C.
At 6th minute when the gas was turned off the water temperature reduced to a temperature of 97.3
°C and that of pot reduced to 89.8 °C. For Stainless pot, the initial temperature of water and pot was
36
36.8 °C and 36.3 °C respectively. At 5th minute, both water and pot reaches a temperature of 100.1
°C and 101.6 °C. At 6th minute when the gas was turned off the water temperature reduced to a
For Iron pot, the initial temperature of water and pot was 34.9 °C and 34.9 °C respectively. At 5th
minute, both water and pot reaches a temperature of 101 °C and 92.1 °C. At 6th minute when the gas
was turned off the water temperature reduced to a temperature of 95.1 °C and that of pot reduced to
86.7 °C. For Clay pot, the initial temperature of water and pot was 33.7 °C and 37.9 °C respectively.
At 9th minute, both water and pot reaches a temperature of 102.7 °C and 123.5 °C. At 10th minute
when the gas was turned off the water temperature reduced to a temperature of 99.1 °C and that of
pot reduced to 86.8 °C.
37
different materials. For Aluminium pot, the initial water temperature was 32.7 °C, while the pot
started at 37.5 °C. By the 6th minute, the water temperature reached a peak at 103.3 °C, and the pot
temperature peaked at 100.5 °C. When the heat source was turned off between the 7th and 8th
minutes, the water temperature decreased from 101.6 °C to 100.7 °C, while the pot temperature
decreased from 90.5 °C to 91.6 °C. For Stainless pot, the initial temperature of water and pot was
35.6 °C and 38.3 °C respectively. At 7th minute, both water and pot reaches a temperature of 101.7
°C and 101.1 °C. At 8th minute when the gas was turned off the water temperature reduced to a
For Iron pot, the initial water temperature was 31.6 °C, while the pot started at 32 °C. During the
experiment, both the water and pot temperatures increased steadily. By the 6th minute, the water
temperature reached 100 °C, while the pot temperature rose to 82 °C. At the end of the 15-minute
period, the water temperature was 84.5 °C, and the pot temperature was 73.1 °C. For Clay pot, the
initial temperature of water and pot was 35.8°C and 43.5°C respectively. At 10th minute, both water
and pot reaches a peak temperature of 102.1°C and 132.6°C. At 11th minute when the gas cooker
was turned off the water temperature reduced to a temperature of 98.4°C and that of pot reduced to
100.1°C.
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4.2 Food Temperature Distribution
Figure 4.10 shows the thermal distribution across the food and pot body per minutes using small pot
sizes of different pot materials with 85 g of rice. At 1 minute the food in the aluminium Pot had a
temperature of 45.8 0C while the aluminium pot itself had a temperature of 51.9 0C. The temperature
of rice and pot increased to 101.3 0C and 107.4 0C respectively at 18 minutes. The food and pot
temperature decreased to 95.7 0C and 93.6 0C respectively after the heating source (gas cooker) was
turned off at 19 minutes. For Stainless Pot, the food had a temperature of 19.7 0C while the pot had a
temperature of 51 0C at 1 minute. The temperature of rice and pot increased to 102.1 0C and 92.8 0C
respectively at 16 minutes. The food and pot temperature decreased to 99.1 0C and 85.6 0C
respectively after the heating source (gas cooker) was turned off at 19 minutes.
39
For Iron Pot, the food had a temperature of 94 0C while the pot had a temperature of 50.1 0C at 1
minute. The temperature of rice and pot increased to 111.3 0C and 90.1 0C respectively at 14 minutes.
The food and pot temperature decreased to 98.8 0C and 69.4 0C respectively after the heating source
(gas cooker) was turned off at 18 minutes. For Clay Pot, the food had a temperature of 44.1 0C while
the pot had a temperature of 50.2 0C at 1 minute. The temperature of rice and pot increased to 133.2
0
C and 152.8 0C respectively at 18 minutes. The food and pot temperature decreased to 109.6 0C and
98.5 0C respectively after the heating source (gas cooker) was turned off at 21 minutes.
Figure 4.10: Temperature distribution for different small sized pots with rice of 85 g
Figure 4.11 shows the temperature distribution across different pot materials with small pot sizes,
along with the temperature changes in the food and pot over time. The experiment involved cooking
170 g of rice. At 1 minute of cooking, the rice inside the aluminium pot reached a temperature of
35.7 °C, while the pot itself was at 62.3 °C. Over the next 15 minutes, the temperature of the rice and
pot increased to 111.5 °C and 103.7 °C, respectively. After the gas cooker was turned off at 20
minutes, the food and pot temperature decreased to 96.8 °C and 89.8 °C, respectively. Similarly, in
40
the Stainless Pot, the food started at a temperature of 33.3 °C, while the pot was at 49.3 °C at exactly
1 minute. At the 21-minute mark, the rice and pot temperature rose to 93 °C and 84 °C, respectively.
When the heating source was turned off at 28 minutes, the food and pot temperature dropped to 74
°C and 73.2 °C, respectively.
For the Iron Pot, the food began at 72.1 °C, and the pot was at 50.2 °C after 1 minute. After 14
minutes, the temperature of the rice and pot increased to 112.6 °C and 83.2 °C, respectively.
Following the cessation of heating at 18 minutes, the food and pot temperature decreased to 94.5 °C
and 77.4 °C, respectively. Lastly, in the Clay Pot, the food had an initial temperature of 34.3 °C, and
the pot was at 56.5 °C after 1 minute. At the 21-minute mark, the rice and pot temperature rose to
142.6 °C and 160.2 °C, respectively. After turning off the gas cooker at 27 minutes, the food and pot
temperature decreased to 109.9 °C and 98.5 °C, respectively.
41
Figure 4.12 shows the thermal distribution across the food and pot body per minutes using small pot
sizes of different pot materials with 250 g of rice. In the Aluminium Pot, at 1 minute of heating, the
food reached a temperature of 32.5 °C, while the pot itself was at 61.1 °C. At 20 minutes, the
temperature of the rice and pot increased to 102.6 °C and 84.5 °C, respectively. Once the gas cooker
was turned off at 26 minutes, the food and pot temperatures decreased to 90.8 °C and 80.2 °C,
respectively. In the Stainless Pot, at 1 minute, the food had a temperature of 33.9 °C, and the pot was
at 52.2 °C. After 13 minutes, the temperature of the rice and pot increased to 112.6 °C and 96.3 °C,
respectively. When the gas cooker was turned off at 23 minutes, the food and pot temperatures
decreased to 96.6 °C and 78.5 °C, respectively.
In the Iron Pot, at 1 minute, the food had a temperature of 63.9 °C, while the pot was at 46.3 °C.
After 13 minutes, the temperature of the rice and pot increased to 117.4 °C and 91.2 °C, respectively.
Once the gas cooker was turned off at 25 minutes, the food and pot temperatures decreased to 103.1
°C and 79.1 °C, respectively. In the Clay Pot, at 1 minute, the food had a temperature of 38.9 °C, and
the pot was at 68.6 °C. After 30 minutes, the temperature of the rice and pot increased to 119.2 °C
and 126.6 °C, respectively. When the gas cooker was turned off at 33 minutes, the food and pot
temperatures decreased to 113.8 °C and 96.8 °C, respectively.
42
Figure 4.13 displays the thermal distribution over time for medium-sized pots made of different
materials and containing 85 g of rice. In the case of the Aluminium Pot, after 1 minute of heating, the
food had a temperature of 25.5 °C, while the pot itself was at 70.2 °C. Over the next 20 minutes, the
temperature of the rice and pot increased to 96.8 °C and 74.2 °C, respectively. Once the gas cooker
was turned off at 21 minutes, the food and pot temperatures decreased to 84.4 °C and 69.5 °C,
respectively. Moving on to the Stainless Pot, at 1 minute, the food had a temperature of 36.1 °C, and
the pot was at 55.8 °C. After 13 minutes, the temperature of the rice and pot increased to 86.6 °C and
100.5 °C, respectively. When the heating source was turned off at 15 minutes, the food and pot
temperatures decreased to 76.7 °C and 98.7 °C, respectively.
For the Iron Pot, at the beginning, the food had a temperature of 58.5 °C, while the pot was at 49.4
°C. Within 9 minutes, the temperature of the rice and pot increased to 117.1 °C and 95.7 °C,
respectively. After the gas cooker was turned off at 14 minutes, the food and pot temperatures
decreased to 95 °C and 71 °C, respectively. Lastly, in the case of the Clay Pot, the food started at a
temperature of 46.7 °C, while the pot had a temperature of 32.9 °C. After 13 minutes, the
temperature of the rice and pot increased to 104.3 °C and 95.7 °C, respectively. When the heating
source was turned off at 20 minutes, the food and pot temperatures decreased to 100.2 °C and 74.4
°C, respectively.
43
Figure 4.13: Temperature distribution for different medium sized pots with rice of 85 g
In Figure 4.14, a graphical representation illustrates the thermal distribution over time for medium
sized pots of various materials and containing 170 g of rice. Aluminium Pot: At the initial 1-minute
mark, the food had a temperature of 33.9 °C, while the pot registered 59.7 °C. Over the next 12
minutes, both the rice and pot temperature gradually increased to 109.6 °C and 95 °C, respectively.
When the gas cooker was turned off at the 18-minute mark, the food and pot temperatures decreased
to 99.8 °C and 85.7 °C, respectively. Stainless Pot: Starting at 36.9 °C for the food and 52.3 °C for
the pot, the temperatures continued to rise over a span of 16 minutes, reaching 112.4 °C for the rice
and 96.8 °C for the pot. After switching off the gas cooker at 18 minutes, the food temperature
decreased to 98.1 °C, while the pot temperature dropped to 87.3 °C.
Iron Pot: With an initial food temperature of 105.8 °C and a pot temperature of 38.9 °C, the rice and
pot temperatures increased to 112.9 °C and 80.4 °C, respectively, after 16 minutes. Following the gas
44
cooker being turned off at the 22-minute mark, the food and pot temperatures declined to 95.6 °C
and 62.9 °C, respectively. Clay Pot: Beginning at 40.3 °C for the food and 48.2 °C for the pot, the
rice and pot temperatures progressively raised to 101.2 °C and 100.6 °C, respectively, after 22
minutes. Once the gas cooker was turned off at 23 minutes, the food temperature decreased to 99.3
°C, while the pot temperature reduced to 88 °C.
Figure 4.15 depicts the temperature distribution across the food and pot body over time using
medium-sized pots made of different materials with 250 g of rice. Aluminium Pot: At 1 minute, the
food temperature was 39.9 °C, while the pot temperature was 28.2 °C. Over the course of 26
minutes, the rice and pot temperatures increased to 138.4 °C and 65.7 °C, respectively. After the gas
cooker was turned off at 35 minutes, the food temperature decreased to 109.1 °C, while the pot
temperature remained at 64.5 °C. Stainless Pot: The food temperature was 45.5 °C, and the pot
45
temperature was 56.2 °C at the 1-minute mark. Subsequently, after 21 minutes, the rice and pot
temperatures rose to 119.9 °C and 96 °C, respectively. When the heating source was switched off at
24 minutes, the food temperature decreased to 97.7 °C, while the pot temperature dropped to 88.5
°C.
Iron Pot: Starting with a food temperature of 42.9 °C and a pot temperature of 49.1 °C at 1 minute,
the rice and pot temperatures increased to 102.3 °C and 80.4 °C, respectively, after 19 minutes.
Following the gas cooker being turned off at 21 minutes, the food temperature decreased to 98.7 °C,
while the pot temperature decreased to 75.7 °C. Clay Pot: At the initial 1-minute mark, the food
temperature was 35.5 °C, and the pot temperature was 40.8 °C. After 23 minutes, the rice and pot
temperatures reached 102.7 °C and 101.8 °C, respectively. When the heating source was turned off at
24 minutes, the food temperature reduced to 101.3 °C, while the pot temperature decreased to
93.2 °C.
46
Figure 4.16 shows the thermal distribution across the food and pot body per minutes using big pot
sizes made of different materials with 85 g of rice. Aluminium Pot: At 1 minute, the food
temperature was 47.6 °C, while the pot temperature was 58.9 °C. As time progressed, the rice and
pot temperatures increased to 138.2 °C and 109.9 °C, respectively, at 11 minutes. After the gas
cooker was turned off at 20 minutes, the food temperature decreased to 101.9 °C, while the pot
temperature reduced to 60.1 °C. Stainless Pot: The food temperature started at 66.2 °C, and the pot
temperature was 53.7 °C at 1 minute. Over the course of 13 minutes, the rice and pot temperatures
rose to 101.6 °C and 101.5 °C, respectively. Once the heating source was switched off at 16 minutes,
the food temperature decreased to 99.2 °C, while the pot temperature dropped to 87.7 °C.
Iron Pot: Starting with a food temperature of 56.3 °C and a pot temperature of 44.5 °C at 1 minute,
the rice and pot temperatures increased to 119.3 °C and 96 °C, respectively, after 13 minutes.
Following the gas cooker being turned off at 18 minutes, the food temperature decreased to 101.1
°C, while the pot temperature decreased to 80.2 °C. Clay Pot: At the initial 1-minute mark, the food
temperatures reached 102.3 °C and 110.3 °C, respectively. When the heating source was turned off at
47
12 minutes, the food temperature reduced to 102 °C, while the pot temperature decreased to 95.6 °C.
Figure 4.16: Temperature distribution for different big sized pots with rice of 85 g
Figure 4.17 shows the thermal distribution across the food and pot body per minutes using big pot
sizes of different pot materials containing 170 g of rice. Aluminium Pot: Initially, at 1 minute, the
food temperature was 35.3 °C, while the pot temperature was 14.6 °C. As time progressed, the rice
and pot temperatures increased to 112.8 °C and 107.2 °C, respectively, at 14 minutes. After turning
off the gas cooker at 18 minutes, the food temperature decreased to 98.6 °C, while the pot
temperature dropped to 92.1 °C. Stainless Pot: The food started at a temperature of 30.4 °C, and the
pot temperature was 58.7 °C at 1 minute. Over the course of 28 minutes, the rice and pot
temperatures rose to 102.4 °C and 136.3 °C, respectively. After the heating source was turned off at
31 minutes, the food temperature decreased to 101.8 °C, while the pot temperature reduced to 82.9
°C.
48
Iron Pot: At 1 minute, the food temperature was 73.3 °C, and the pot temperature was 45.6 °C. As
time progressed, the rice and pot temperatures increased to 126.6 °C and 91.4 °C, respectively, at 12
minutes. After the gas cooker was turned off at 19 minutes, the food temperature decreased to 99.9
°C, while the pot temperature dropped to 87.8 °C. Clay Pot: Initially, at 1 minute, the food
temperatures reached 101.5 °C and 111.2 °C, respectively. Following the turning off of the gas
cooker at 18 minutes, the food temperature decreased to 102.1 °C, while the pot temperature
decreased to 99.4 °C.
Figure 4.17: Temperature distribution for different big pots sizes with rice of 170 g
Figure 4.18 shows the temperature distribution across the food and pot body per minutes using big
pot sizes of different materials containing 250 g of rice. In the case of the Aluminium Pot, after 1
minute of cooking, the food reached a temperature of 60.6 °C, while the pot itself was at 49.6 °C.
Over a span of 28 minutes, the rice and pot temperatures increased to 102.9 °C and 106.1 °C,
respectively. When the gas cooker was turned off at 29 minutes, the food temperature dropped to
49
102.6 °C, and the pot temperature decreased to 90.5 °C. Regarding the Stainless Pot, at 1 minute, the
food started at a temperature of 29.1 °C, and the pot was at 46.7 °C. After 29 minutes, the rice and
pot temperatures rose to 102.1 °C and 104.4 °C, respectively. Once the heating source was turned off
at 30 minutes, the food temperature decreased to 101.2 °C, and the pot temperature lowered to 86.5
°C.
For the Iron Pot, the food began with a temperature of 51.7 °C, while the pot had a temperature of
33.9 °C at 1 minute. Within 20 minutes, the rice and pot temperatures increased to 131.3 °C and 96.4
°C, respectively. After turning off the gas cooker at 34 minutes, the food temperature decreased to
96.6 °C, while the pot temperature decreased to 71.6 °C. Lastly, with the Clay Pot, at 1 minute, the
food had a temperature of 44.2 °C, and the pot was at 68.7 °C. After 16 minutes, the rice and pot
temperatures increased to 102.4 °C and 114.6 °C, respectively. When the heating source was turned
off at 18 minutes, the food temperature dropped to 100.2 °C, and the pot temperature decreased to
95.5 °C.
Figure 4.18: Temperature distribution for different big pots sizes with rice of 250 g
50
4.3 Cooking Power and Cooking Efficiency
Figure 4.19 shows the cooking power and time used in heating 1 kg of water quantity for small sized
pots of different materials. For Aluminium pot, the highest values are observed at the 2nd minute,
with a cooking efficiency of approximately 70% and a cooking power of around 1751.14 W. After
the peak, both parameters gradually decrease. For Stainless pot, the cooking efficiency increased
from 0 at time 0 to a peak value of approximately 77.86% at the 1st minute. However, from the 2nd
minute onwards, the cooking efficiency gradually decreased. Similarly, the cooking power starts at 0
and increases to its peak value of 1946.49 W at the 1st minute, but then decreased over time.
For Iron pot, the cooking efficiency initially increased, reaching its peak value of approximately
65.9% at the 1st minute. However, from the 2nd minute onwards, the cooking efficiency gradually
decreased. Similarly, the cooking power started at 0 and increased to its peak value of 1646.49 W at
the 1st minute, but then decreased over time. By the 4th minute, the cooking efficiency has dropped
to approximately 47.8% and the cooking power to around 1194.75 watts. For Clay pot, the cooking
efficiency shows a slight increase initially, reaching a peak value of approximately 30.1% at the 4th
minute. However, it fluctuates around this peak value in the subsequent minutes. The cooking power
follows a similar trend, with a peak value of around 753.48 W at the 4th minute.
51
Figure 4.19: Cooking Power for different small sized pots with 1 kg of water quantity.
pots of different materials. For Aluminium pot, the cooking efficiency starts at 0 and gradually
increased, reaching a peak value of approximately 59.2% at the 3rd minute. After that, the efficiency
remained relatively stable. Similarly, the cooking power increased initially and reached a peak value
of around 1479.05 W at the 3rd and 4th minute, followed by a slight decrease. For Stainless, the
cooking efficiency started at 0 and gradually increased, reaching its highest value of approximately
152.4% at the 1st minute. However, from the 2nd minute onwards, the cooking efficiency decreased
steadily. The cooking power followed a similar trend, starting at 0 and peaking at around 3809.26 W
at the 1st minute, but then gradually decreasing.
For Iron pot, the cooking efficiency starts at 0 and gradually increased, reaching a peak value of
approximately 82% at the 1st minute. However, from the 2nd minute onwards, the cooking
efficiency fluctuates but generally decreases. The cooking power follows a similar trend, starting at 0
and peaking at around 2051.14 W at the 1st minute, but then shows variations with a general
52
decreasing trend. For Clay Pot, the cooking efficiency fluctuates over the observed time period, with
a peak value of approximately 39.6% at the 8th minute. The cooking power starts at 0 and gradually
increases, peaking at approximately 990.69 W at the 8th minute. However, after the peak, the
cooking power fluctuates and generally shows a decreasing trend.
pots of different materials. For Aluminium pot, the cooking power steadily increases from 0 to a
peak value of approximately 1862.77 W at the 3rd minute. After reaching the peak, the cooking
power fluctuates but generally decreases. The cooking efficiency, on the other hand, starts at 0 and
gradually increases, reaching its highest value of approximately 74.5% at the 3rd minute. It then
fluctuates but remains relatively high throughout the observed time period. For Stainless pot, the
cooking power starts at 0 and gradually increased, reaching its peak value of approximately 4311.58
W at the 1st minute. However, from the 2nd minute onwards, the cooking power shows a decreasing
53
trend with fluctuations. The peak cooking efficiency was observed at the 1st minute, with a value of
approximately 172.5%. However, the cooking efficiency also decreases over time.
For Iron pot, the cooking power increased from 0 and peaked at approximately 3055.78 W at the 1st
minute. However, it gradually decreased over subsequent minutes. The peak cooking efficiency was
observed at the 1st minute, with a value of approximately 122.2%. However, the cooking efficiency
also decreased over time. For Clay pot, the cooking power gradually increased, reaching its highest
point at approximately 1967.42 W during the 1st minute. However, it started to decline in subsequent
minutes. The cooking efficiency peaked at the 1st minute, with a value of around 78.7%.
Following the peak, the cooking efficiency showed fluctuations but generally decreased over time.
Figure 4.22 shows the cooking power and time used in heating 1 kg of water quantity for medium
sized pots of different materials. For Aluminium pot, the cooking power gradually increased from 0
and reached its peak at approximately 837.2 W during the 1st minute. Following the peak, the
cooking power remained relatively stable with minor fluctuations. The highest cooking efficiency
54
was observed at the 5th minute, with a value of approximately 31.8%. However, the cooking
efficiency experienced variations throughout the observed time. For Stainless pot, the cooking power
gradually increased, peaking at around 1667.42 W during the 1st minute. However, it then showed a
downward trend with fluctuations. On the other hand, the cooking efficiency followed a similar
trend.
For Iron pot, the cooking power gradually increased, peaking at approximately 1590.68 W during the
2nd minute. However, it then showed a declining trend with subsequent decreases. On the other
hand, the cooking efficiency started moderately high, but fluctuated throughout the observed time
period. For Clay pot, the cooking power gradually increased, reaching its peak around 896.50 W
during the 2nd minute. However, it then displayed a slight decline with subsequent fluctuations.
Meanwhile, the cooking efficiency showed variations throughout the observed time period,
gradually decreasing over time.
Figure 4.22: Cooking Power for different medium sized pots with 1 kg of water quantity.
55
sized pots of different materials. For Aluminium pot, the cooking power gradually increased,
reaching a peak value of approximately 2379.04 W during the 2nd minute. Subsequently, it
displayed a slight decrease while exhibiting fluctuations. On the other hand, the cooking efficiency
showcased variations throughout the observed time period, demonstrating a general decreasing
trend. For Stainless pot, the cooking power gradually increased, reaching its highest point at
approximately 1925.56 W during the 1st minute. However, it then showed a downward trend with
subsequent fluctuations. On the other hand, the cooking efficiency started moderately high, but
gradually decreased over time, demonstrating variations throughout the observed period.
For Iron pot, the cooking power gradually increased, reaching a peak of approximately 2525.55 W
during the 1st minute. However, it then exhibited a declining trend with subsequent fluctuations. In
contrast, the cooking efficiency started at a high level but gradually decreased over time,
demonstrating variations throughout the observed period. For Clay pot, the cooking power gradually
increased, reaching its peak value of approximately 1010.22 W during the 5th minute. Subsequently,
it displayed slight fluctuations but remained relatively stable. On the other hand, the cooking
efficiency showed variations throughout the observed time period, initially increasing and then
reaching a relatively stable level.
56
sized pots of different materials. Aluminium pot, the cooking power gradually increased, reaching its
peak value of approximately 3641.82 W during the 1st minute. However, it then exhibited a
declining trend with subsequent fluctuations. In contrast, the cooking efficiency displayed variations
throughout the observed period, initially starting at a high level and later stabilizing. For Stainless,
The cooking power initially increased, reaching a peak value of approximately 2909.27 W during the
first minute. However, it gradually decreased over subsequent intervals. Similarly, the cooking
efficiency varied, with initial high values followed by a downward trend.
For Iron pot, the cooking power experienced a notable increase, reaching its peak at 4960.41 W
during the first minute. However, it gradually decreased in subsequent intervals. On the other hand,
the cooking efficiency exhibited a similar trend, starting high and gradually declining over time.
Clay pot cooking power initially started at 0 and gradually increased over time, reaching a peak of
57
1299.56 W at the eleventh interval. The cooking efficiency displayed fluctuations throughout the
intervals, with some variations in its values.
Figure 4.25 shows the cooking power and time used in heating 1 kg of water quantity for big sized
pots of different materials. Aluminium pot, the cooking power started at 0 and gradually increased
over time, reaching a peak of 1866.26 W at the second interval. The cooking efficiency also
displayed variations throughout the intervals, with some fluctuations in its values. Stainless pot
cooking power started at 0 and gradually increased over time, reaching a peak of 1455.79 W at the
third interval. The cooking efficiency for stainless pot also displayed variations throughout the
intervals, with some fluctuations in its values.
Iron pot cooking power started at 0 and gradually increased over time, reaching its peak at 1159.87
W during the fourth interval. The cooking efficiency, on the other hand, exhibited some variations
throughout the intervals. It started at 0, increased in the first interval, decreased in the second
58
interval, and fluctuated thereafter. In Clay pot, the cooking power gradually increased over time,
starting from 0 and reaching a peak of 1144.17 W during the first interval. However, it experienced
some fluctuations afterward, with slight decreases and increases. On the other hand, the cooking
efficiency showed a decreasing trend throughout the intervals. It started at 45.7%, gradually
decreased, and reached its lowest point at 27.62%.
Figure 4.25: Cooking Power for different big sized pots with 1 kg of water quantity.
pots of different materials. Aluminium pot cooking power exhibited a positive trend over time,
starting from 0 and steadily increasing. It reached its peak at 2902.29 W during the first interval and
maintained relatively high values in the subsequent intervals. In contrast, the cooking efficiency
started at a high value of 116%, then, it gradually decreased. The cooking power for Stainless pot
increased gradually over the observed time intervals, starting from 0 and reaching a peak of 3865.07
W during the first interval. It then gradually decreased but remained at relatively high levels
throughout the subsequent intervals.
59
The cooking power for Iron pot shows a relatively stable pattern with some fluctuations. It starts at 0
and gradually increases over time, reaching a peak of 2539.51 W during the first interval. However,
there is a slight decline in the subsequent intervals, but the power remains at relatively high levels.
On the other hand, the cooking efficiency also exhibits a similar trend, starting from 0 and gradually
increasing. It reaches a peak of 101% during the first interval and then fluctuates around a slightly
lower value in the following intervals. Clay pot cooking power starts at 0 and gradually increases,
reaching a peak of 1395.33 W during the first interval. However, the power decreases in the
subsequent intervals, with some fluctuations. Similarly, the cooking efficiency also starts relatively
low at 0 and increases gradually. It reaches its peak value of 55.8% during the first interval and
fluctuates around a slightly lower value in the following intervals.
Figure 4.26: Cooking Power for different big sized pots with 2 kg of water quantity.
pots of different materials. Aluminium pot cooking power steadily increases over time, starting at 0
60
and reaching a peak of 7053.41 W during the first interval. This indicates a higher energy output for
cooking. Similarly, the cooking efficiency also increases over time, starting at 0 and reaching a peak
value of 282% during the first interval. Stainless pot cooking power steadily increases over time,
starting from 0 and reaching a peak value of 4939.48 Watts during the first interval. This indicates a
significant energy output for cooking. On the other hand, the cooking efficiency also shows a
consistent pattern. It starts from 0 and reaches a peak value of 197% during the first interval.
Iron pot cooking power gradually rises from 0 to a peak value of 6237.14 W during the first interval.
Simultaneously, the cooking efficiency also demonstrates an upward trend, starting from 0 and
reaching a maximum value of 249% during the first interval. The cooking power for Clay pot
gradually increases over time, starting from 0 and reaching a peak value of 1728.81 W during the
fifth interval. This indicates a significant increase in the amount of energy being used for cooking
simultaneously, the cooking efficiency exhibits a fluctuating trend. It starts at 0 during the first
interval, and then rises gradually until the fifth interval, where it reaches a peak value of 69%.
Figure 4.27: Cooking Power for different big sized pots with 3 kg
61
4.4. ENERGY BALANCE
Table 3.5 shows the energy balance on energy utilization of selected pot types and sizes based on the
amount of water heated. The table shows that energy utilization varies significantly depending on pot
type, size, and the amount of water heated. Aluminium pots generally exhibit higher energy
utilization values compared to other materials like Clay, Iron, and Stainless. The amount of water
heated is another factor influencing energy utilization. When larger quantities of water were heated,
the total energy used (Qtot) tends to be higher. These factors indicate that the choice of pot material
and the volume of water being heated affect the thermal performance and energy balance of cooking.
Table 3.5: Energy balance on energy utilization of selected pot types and sizes based on the amount of
water heated.
Pot type Pot Size Water Heated Time Qw QP Qk Qtot Qac Qu
(kg)
Aluminium Big 1 3 279624.80 17899.29 30873.60 450000.00 328398.31 121601.69
2 5 540831.20 22263.16 46310.40 750000.00 609405.49 140594.51
3 6 886594.80 23298.66 69465.60 900000.00 979360.05 0.00
Medium 1 6 257439.00 23096.61 46310.40 900000.00 326846.30 573153.70
2 6 556738.00 23735.23 38592.00 900000.00 619065.85 280934.15
3 7 840130.20 20728.41 30873.60 1050000.00 891733.01 158266.99
Small 1 5 290927.00 19589.95 54028.80 650000.00 362086.83 287913.17
2 7 567621.60 17336.47 30873.60 1050000.00 615832.21 434167.79
3 10 860223.00 17239.97 30873.60 1500000.00 908337.14 591662.86
Clay Big 1 7 290089.80 141419.46 331891.20 1050000.00 763400.74 489993.54
2 9 577668.00 133027.54 23155.20 1150000.00 733851.24 468898.09
3 10 832595.40 138466.75 23155.20 1200000.00 994218.04 260132.46
Medium 1 7 283392.20 104970.17 23155.20 1050000.00 411517.84 638482.16
2 11 546691.60 80239.54 54028.80 1250000.00 677828.55 572171.45
3 11 857711.40 64580.41 46310.40 1250000.00 966982.99 476153.71
Small 1 7 290089.80 57552.90 46310.40 1050000.00 393953.38 656046.62
2 12 560086.80 55129.62 61747.20 1800000.00 669245.56 1146933.12
62
3 11 833851.20 57492.32 23155.20 1650000.00 914499.22 735500.78
Iron Big 1 5 290927.00 27438.39 15436.80 750000.00 333802.58 416197.42
2 5 553389.20 26966.94 7718.40 750000.00 588075.28 161924.72
3 6 858967.20 23572.50 38592.00 900000.00 921132.65 0.00
Medium 1 5 292601.40 22173.87 787276.80 750000.00 1102052.46 319417.44
2 6 530784.80 24387.44 15436.80 900000.00 570609.62 329390.38
3 5 880315.80 19540.48 23155.20 750000.00 923012.65 0.00
Small 1 4 286741.00 12935.24 0.00 600000.00 299676.72 300323.28
2 7 555063.60 14335.45 15436.80 1050000.00 584836.38 465163.62
3 9 815014.20 15691.20 15436.80 1350000.00 846142.81 503857.19
Stainless Big 1 4 277950.40 18113.71 15436.80 600000.00 311501.37 288498.63
2 5 529947.60 21545.08 23155.20 750000.00 574648.59 175351.41
3 7 830083.80 20720.23 38592.00 1050000.00 889396.82 160603.18
Medium 1 4 284648.00 21558.42 23155.20 600000.00 329362.09 270637.91
2 7 541668.40 17948.03 15436.80 1050000.00 575053.75 474946.25
3 10 811246.80 15350.63 23155.20 1500000.00 849753.17 650246.83
Small 1 4 282136.40 14373.45 0.00 600000.00 296510.32 303489.68
2 6 551714.80 15076.15 15436.80 900000.00 582228.37 317771.63
3 8 820037.40 14522.51 7718.40 1200000.00 842278.99 357721.01
4.5. COMPARATIVE ANALYSIS
Table 3.6 shows the comparative analysis of the effect of amount of water heated on energy utilization of
selected cooking pots. Aluminium pots generally exhibit high energy utilization with a significant portion of
the energy being accountable (Qac). Clay pots show mixed results with varying energy utilization across
scenarios, making it less consistent in terms of efficiency. Iron pots, especially in the "Big" and "Medium"
sizes, also display relatively high energy utilization. Stainless pots yield mixed outcomes, with some
scenarios being energy-efficient while others are less so. Larger pot sizes consistently require more energy
compared to smaller sizes, this is expected since heating a larger quantity of water requires more energy.
63
Table 3.6: Effect of amount of water heated on energy utilization of selected cooking pots
Pot type Pot Size Water Heated (kg) Time Qw QP Qk Qtot Qac Qu
1 (A) C
2 (B) C
Big
3 (C) A A
1 (A) C
2 (B)
Aluminium Medium
3 (C) A
1 (A) BC
2 (B)
Small
3 (C)
1 (A)
2 (B)
Big
3 (C) A
1 (A)
2 (B)
Clay Medium
3 (C)
1 (A)
2 (B) C
Small
3 (C) A A
Iron 1 (A) C
2 (B) C
Big
3 (C) A A
1 (A)
2 (B) C
Medium
3 (C)
Small 1 (A)
2 (B)
64
3 (C)
1 (A) C
2 (B)
Big
3 (C) A A
1 (A)
2 (B)
Stainless Medium
3 (C) A B A
1 (A)
2 (B) C
Small
3 (C) A A
Table 3.7 shows the comparative analysis of effect of pot sizes on energy utilization of selected cooking pots.
The data consistently highlights that the size of the pot (Big, Medium, and Small) has a notable influence on
energy utilization during cooking. Larger pots generally demand more energy compared to smaller ones,
when the same amount of water is heated. This shows that pot size has a significant impact on energy
utilization. The data also reveals that the effect of pot size on energy utilization can vary depending on the
pot type. Different materials (Aluminium, Clay, Iron, Stainless) exhibit unique characteristics in terms of
heat transfer and efficiency. This indicates that the selected cooking pots can be energy-efficient under
specific conditions.
In summary, the filled areas of the table demonstrate that pot size plays a significant role in energy utilization
during cooking. Smaller pot sizes generally tend to be more energy-efficient, but the specific trends can vary
depending on the pot type and other factors.
Table 3.7: Effect of pot sizes on energy utilization of selected cooking pots
Water
Pot
Heated Pot Type Time Qw QP Qk Qtot Qac Qu
Size
(kg)
1 Aluminiu Big (A)
m
Medium (B)
65
Small (C)
Big (A)
Medium (B)
Clay
Small (C)
Big (A)
Medium (B)
Iron
Small (C)
Big (A)
Medium (B) C
Stainless
Small (C)
Big (A)
Aluminiu Medium (B)

m
Small (C) A
Big (A) BC
Medium (B)
Clay
Small (C)
2
Big (A)
Medium (B)
Iron
Small (C)
Big (A)
Medium (B)
Stainless
Small (C)
3 Big (A)
Aluminiu Medium (B) A

m
Small (C) AB
Clay Big (A) BC
Medium (B)
66
Small (C)
Big (A)
Medium (B)
Iron
Small (C) AB
Big (A) C
Medium (B) C A
Stainless
Small (C)
Table 3.8 shows the comparative analysis on effect of pot types on energy utilization of selected cooking
pots. Clay pots across all scenarios, tend to have lower heat discharge to the kitchen environment (Q k)
compared to other pot types, indicating that they retain heat well due to high specific heat capacity of clay.
Heating 1 kg of water typically results in lower energy utilization compared to higher water quantities. As the
quantity of water increases to 2 kg and 3 kg, the energy utilization increases accordingly. However, the
relative performance of different pot types and sizes remains relatively consistent. Small pots especially
iron(C) and Stainless (D) small pots consistently show higher heat discharge to the kitchen compared to other
pot types. The blank spaces indicate that they have no significant effect.
Table 3.8: Effect of pot types on energy utilization of selected cooking pots
Water Heated Pot Size Pot Type Time Qw QP Qk Qtot Qac Qu
(kg)
1 Aluminiu
(A)
m
Clay (B) ACD
Big
Iron (C)
Stainless (D)
Medium Aluminiu
(A)
m
Clay (B) ACD
67
Iron (C)
Stainless (D)
Aluminiu
(A) CD
m
Clay (B) ACD
Small
Iron (C)
Stainless (D)
Aluminiu
(A)
m
Clay (B) ACD ACD
Big
Iron (C)
Stainless (D)
Aluminiu
(A)
m
Clay (B) ACD AC
2 Medium
Iron (C)
Stainless (D)
Aluminiu
(A)
m
Clay (B) ACD CD CD
Small
Iron (C)
Stainless (D)
3 Aluminiu
(A)
m
Clay (B) ACD ACD
Big
Iron (C)
Stainless (D) A
Medium Aluminiu
(A)
m
Clay (B) ACD AC
Iron (C)
Stainless (D) C
68
Aluminiu
(A) CD
m
Clay (B) ACD D
Small
Iron (C)
Stainless (D)
CHAPTER FIVE
CONCLUSION AND RECOMMENDATION
5.1 Conclusion
This study aimed to investigate the thermal performance and energy balance of food cooking using selected
pot types (aluminium, stainless, iron and clay). Different water quantities of 1 kg, 2 kg, 3 kg and different
quantities of rice 85 g, 170 g and 250 g were experimented on. Through a meticulous experimental setup and
comprehensive data analysis, we have gained valuable insights into the effects of pot material on cooking
efficiency, cooking power and energy balance. The findings of this study shed light on the diverse
temperature distribution and heat retention properties of the different pot materials. Aluminium pots
demonstrated rapid heating but tended to lose heat quickly. Stainless steel exhibited balanced performance
with moderate heating rates and heat retention. Iron and clay pots displayed slower heating rates but
excellent heat retention, contributing to energy savings over prolonged cooking periods. These results
reinforce the importance of pot selection in optimizing energy usage during food preparation. By making
informed decisions about pot selection based on cooking requirements and material properties, individuals
can contribute to reducing energy consumption and minimizing environmental impact.
5.2 Recommendation
The following recommendations were suggested for further studies:
69
I. Experimenting on different food types, such as beans, yam, vegetables, corn, or soups. Different
food items have varying thermal characteristics, and their interaction with different pot types can
yield diverse results.
II. Further research should delve deeper into the effects of pot shapes on thermal performance and
energy balance. This will help to provide a more understanding of the pot types' performance.
III. Different heat source should be used to carry out the experiment, such as electric cooker or
biofuel.
References
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73

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THERMAL PERFORMANCE AND ENERGY BALANCE OF FOOD COOKING USING

SELECTED POT TYPES AND SIZES

ADENIYI ADEMOLA JOHNSON

AKINTOLA ABIDEEN ISOLA

OLADUNJOYE EMMANUEL ABIODUN

A PROJECT SUBMITTED TO THE DEPARTMENT OF AGRICULTURAL ENGINEERING,

FACULTY OF ENGINEERING, COLLEGE OF ENGINEERING AND ENVIRONMENTAL

IN PARTIAL FUFILMENT OF REQUIREMENTS FOR THE AWARD OF BACHELORS

DEGREE IN AGRICULTURAL ENGINEERING, OLABISIONABANJO UNIVERSITY, AGO -

IWOYE, OGUN STATE, NIGERIA.

Adeniyi Ademola Johnson ………………………..…..

Akintola Abideen Isola …………………………....

Oladunjoye Emmanuel Abiodun ……………………………..

Knowledge and literary presentation.

whose mercy and omnipotence made this work a reality.

the successful completion of this project.

contributions of the faculty members of the Agricultural Engineering department at Olabisi

dedication to teaching and research has been a constant source of inspiration.

necessary insights and perspectives for this research.

the experiments and analysis.

either big or small.

Plate 2.1: Iron Pot ……………………………………………………………………...……8

Plate 2.2: Stainless Pot ……………………………………………………………………....8

Plate 2.3: Aluminium Pot ……………………………………………………………….…...9

Plate 2.4: Clay Pot ………………………………………………………………………….10

Plate 3.2: Digital Electronic Weighing Balance …………………………………………....16

Plate 3.3: Digital Hygrometer ……………………………………………………………....17

Table 3.1 Aluminum pots specification ………………………....13

Table 3.2 Stainless pots specification ……………………….......13

Table 3.3 Stainless pots specification …………………………...14

Table 3.4 Clay pots specification……………………………..….14

Table 3.5 Energy balance ………………………………………..63

Table 3.6 Comparative analysis …………………………………64

Table 3.7 Comparative analysis …………………………………66

Parameters Meaning Unit

Quantity of heat transferred to water j

Quantity of heat transferred to pot j

Quantity of heat transferred to wall j

Specific heat capacity of pot j/kg0c

Change in pot temperature C

Change in wall temperature C

Specific heat capacity of water j/kg0c

Specific heat capacity of air j/kg0c

Change in air temperature C

Change in water temperature C

Mass of gas used by minute g

Initial mass of water Kg

Density of air at room temperature kg/m3

Total amount of heat transferred j

Calorific value of cooking gas kj/g0c

selected for the experiment: aluminum, stainless, iron and clay.

MS Excel and SPSS to carry out comparative analysis.

1.1 General Background

which in turn affects the quality of the final product.

(Paisarn N., 2014).

efficiency of cook stove.

1.2 Problem Statement

and sizes heating different quantities of water.

different cook pots, (Iron, Stainless & aluminum) of different sizes.