ABSTRACT
Thermal properties refer to characteristics of a material defining the substance and related to
temperature dependent. The most important thing in building design is the protection of people who
live and work within the environment. The research work identified some common roofing materials
used for building design in Nigeria.. The samples include aluminium (coated), Zinc and stone coated.
The investigation was done using Ohm‟s law and Frankz Weidman principle. The thermal properties
investigated were thermal conductivity, thermal absorptivity, thermal diffusivity, thermal resistivity
and specific heat capacity. with the view of establishing their suitability as roofing materials in
building design in Nigeria based on climate and weather condition of particular location. the results
show that zinc has the highest thermal conductivity
,thermal absorptivity
,
and specific heat capacity
and also the lowest thermal diffusivity
andthermal resistivity while stone coated material has the least thermal
conductivity
, absorptivity
,and specific heat capacity
and also the highest rate of thermal diffusivity
, and thermal resistivity
Aluminum coated is within the range of both sample, with thermal conductivity
,
thermal absorptivity
, thermal diffusivity
, thermal resistivity
and specific heat capacity
.Thus stone coated material may be
recommended for roofing of building where the temperature is high and zinc may be recommended
for roofing of buildings where temperature is low. For normal temperature range, Aluminium
material may be recommended.
TABLE OF CONTENTS
TITLE PAGE i
DECLARATION ii
CERTIFICATION iii
DEDICATION iv
ACKNOWLEDGEMENT .v
TABLE OF CONTENTS vii
LIST OF TABLES x
LIST OF FIGURES xi
ABSTRACT xii
CHAPTER ONE: INTRODUCTION
1.1. Background of the study 1
1.2 Aim and objectives 2
1.3 Significance of the study 3
1.4 Scope and limitation of the study 3
1.5 Definition of terms 3
CHAPTER TWO: REVIEW OF RELATED LITERATURE
2.1. Thermal Properties of Roofing Material 5
2.2. Thermal Conductivity 5
2.3. Method of Measuring Thermal Conductivity 5
2.3.1 Steadyâ€Â�State Method 5
2.3.2 Axial Flow Methods 6
2.3.3 Guarded Hot Pla.. bte Method 6
2.3.4 Direct Heating Method 7
2.3.5 Comparative Method 7
2.3.6 Heatâ€Â�Flow Meters Method 8
2.3.7 System Design Method 8
2.3.8 Advantages of the Steadyâ€Â�State Methods to Other Methods 8
2.3.9 Disadvantages of the Steadyâ€Â�State Methods to Other Methods 9
2.3.10 Determination of Thermal Conductivity in Steady State 9
2.3.11 Non steady state or Transient Method 10
2.3.12 Laser Flash Method 10
2.3.13 Hotâ€Â�Disk Method 10
2.4 Thermal Resistivity (R) 12
2.5 Thermal Conductance(C) 12
2.6 Thermal Diffusivity 12
2.7 Thermal Absorptivity 13
2.8 Specific Heat Capacity 13
2.9 Relationship between Thermal Conductivity Thermal Diffusivity, Density and
Specific Heat Capacity 13
2.10 Heat Transfer 15
2.10.1 Conduction 16
2.10.2 Convection 16
2.10.3 Radiation 16
2.11 Heat Transfer through A Roof 17
2.12 Thermal Radiation 18
2.13 Solar Radiation 18
2.14 Solar Absorption 19
2.15 Roof Colour 20
2.16 Review of Previous Work 21
CHAPTER THREE: MATERIALS AND METHODS
3.1 Materials 23
3.2 Sample preparation 24
3.3 Methods 24
3.4 Circuit Diagram 26
3.5 Experimental Procedure for Electrical Conductivity 27
3.6 Experimental Procedure for Specific Heat Capacity 28
3.7 Experimental Procedure for Density 28
CHAPTER FOUR: RESULT AND DISCUSSION
4.1 Result of sample dimensions and mass measurement 29
4.2 Computation of Cross Sectional Area of the Sample 29
4.3 Density of Each Sample 30
4.4 Experimental Results of Resistance, Electrical Resistivity and
Electrical Conductivity 30
4.5 Results of thermal properties of the sample 32
4.6 Graphical Analysis of Result 34
CHAPTER FIVE: SUMMARY CONCLUSION AND RECOMMENDATION
5.1 Summary 39
5.2 Conclusion 40
5.3 Recommendation 40
References
LIST OF TABLES
TABLE PAGE
4.1 Sample dimension and Mass 29
4.2 Cross sectional area of each sample 30
4.3 Density of each sample 30
4.4 Experimental results of resistance, electrical resistivity and
electrical conductivity 32
4.5 Statistics of thermal properties of different roofing samples 33
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Provision of housing among other social amenities occupies a strategic position in most development
plans for developing Nations such as Nigeria (Chukwucha, and Owate, 2002). One of the
fundamental requirements of buildings is the protection of the people who live and work within them
from hash weather. Thus, objective of environmental building design is the creation of a comfortable
yet efficient internal environment (Camilleri, 2000).
The design of the building envelope is crucial towards attaining an optimal configuration, which
responds effectively to environmental changes in order to reduce their impact. The understanding of
energy related characteristics and the evaluation of the relevant properties of the building envelope is
an integral part of every environmental assessment. Solar energy affects significantly, the interior
environment and the energy requirements of buildings. (Lattimer & Ouelletes 2006).
However, one way to reduce the heat flux is the use of radiant barriers which reduce the heat flux
through radiation. Most building materials particularly, roofing materials are good conductor of heat.
Materials like metal and tile are commonly used in the form of sheet metal for roofing in building
construction.
The knowledge of thermal properties of different roofing material is very important in the choice of
the type of material to be used in the construction of a self- cooling or passively cooled building
design. (Etuk, et al., 2008 & Michael, et al., 2008)
However, roofing systems used in the formal and residential sector are predominantly timber or
metal truss systems with tile or profiled steel roofing, generally these roofing systems will be
complimented with a plasterboard ceiling, regulations which require that these roof assemblies are
insulated.
Therefore, thermal insulation is applied above the ceiling to achieve the thermal resistance
requirements. The requisite thermal resistance can be achieved by adding additional layers of fibrous
loft insulation or with reflective foil layers to create air-spaces or by making use of thermally
insulating board products.(Safintra roofing and steel South Africa, 2016).
In the recent observation, it has shown that roofing materials used in building design doesn‟t take
sufficient account of climate and environmental factors in the design, most especially with the
regards to the choice of roofing materials to be used. These situations would increase the energy
consumption for heating and cooling in buildings and affects comfort, health and efficiency.
Therefore, it is important to carry out adequate research on thermal properties of these roofing
materials.
1.2 Aim and Objectives
The aim of this research is to measure and compare the thermal properties of some common roofing
materials in building design in Nigeria.
The Objectives are;
i. To identify common roofing material used for buildings in Nigeria
ii. To measure and compare specific heat capacity of these materials
iii. To measure and compare thermal conductivity as well as to evaluate thermal resistivity of
the materials
iv. To measure and compare thermal diffusivity of material
v. To measure and compare thermal absorptivity of material
1.3 Significance of the study
The result of this research would enable the builder in Nigeria, to choose the best roofing materials
for the residential and industries construction that will prevent any outbreak.
1.4 Scope of the study
This research work focuses on identifying the common roofing material in Nigeria for building
design. The thermal properties of these roofing materials will then be study comparatively by
measuring conductivity, resistivity, absorptivity, diffusivity and specific heat capacity of the roofing
material. The measurement will be carry out in the laboratory for necessary computations, at the end
of the experiment the result will be show graphically.
1.5 Definition of Terms
Temperature: is measure the degree of hotness or coldness expressed in terms of any several
arbitrary scales and indicating the direction in which energy will spontaneously flow, i.e. from higher
body to lower body .Thermometer is an instrument use to measure the temperature of a system.
Heat (Q): is the transfer of energy between two objects due to temperature differences. Without
external agent doing work, heat will flow a hotter to a cooler object. Two objects of different
temperature always interact. Heat can be flow in three different ways from one object to another
through conduction, convection and radiation.
Heat flux: is the rate of heat energy transfer through a given surface per unit time.
Thermal properties: any characteristic of a material defining the substance and related to
temperature; e.g. thermal conductivity is said to be a thermal property, but electrical conductivity is
not.
Weather: is the state of the atmosphere to the degree of hot or cold, wet or dry calm or stormy, clear
or cloudy. Weather is driven by air pressure, temperature and moisture difference between one place
and another.
.
