ASPECT RATIO OF BUILDING FORM AS A TOOL FOR ENHANCING THERMAL COMFORT IN THE DESIGN OF A TELECOMMUNICATIONS OFFICE BUILDING (MAIDUGURI)

ladychampionz August 5, 2021 ARCHITECTURE PROJECT TOPICS AND MATERIALS, PROJECT TOPICS No Comments

: Ms Word, Ms Word Format
: 100 Pages
: ₦5000
: 1-5 Chapters

ASPECT RATIO OF BUILDING FORM AS A TOOL FOR ENHANCING THERMAL COMFORT IN THE DESIGN OF A TELECOMMUNICATIONS OFFICE BUILDING (MAIDUGURI)

ABSRACT

Thermal comfort is recognized as a key parameter for healthy and productive large workspaces found in office buildings. Achieving occupants comfort is a priority that has a great effect on energy demand in buildings, particularly in hot climate zones. The study aims at investigating a suitable aspect ratio of building form that will reduce the costly effects of providing thermal comfort to occupants in buildings in a hot-dry climate of Nigeria.

A case study approach was adopted to study the geometric properties of existing similar office buildings which were chosen purposively and a quantitative research method was used for the collection of data through computer simulation. Firstly, the study examined the thermal performance of different building forms with the same floor area against their volume to surface ratio (V/S). Forms with good thermal performance were optimized with different aspect ratios elongated along east-west orientation. ECOTECT program was used to study the energy performance of the forms on exposed surfaces.

From the deduction of the study, the west and south surfaces are the most exposed (in terms of heat gain and incident light), both the cube and cylinder forms were optimized with various aspect ratios and simulations were conducted to observe the extent to which solar radiation could be reduced on exposed west surfaces during hot periods and maximized on south surfaces during cold periods.

The study showed that a slight change in the volume to surface ratio could have a significant impact in a building’s energy performance, and also significant thermal

environment can be attained during both hot and cold periods when optimized with an optimum aspect ratio of (1:1.7) as compared to aspect ratio (1:1). 33% and 28% energy are further saved on south and west surfaces respectively when aspect ratio “1:1.7” (ideal ratio) is compared with aspect ratio “1:1”. Also, it was noted that the incident solar radiation decreases from aspect ratio 1:1.7 indicating 71% exposure, 1:1 and 1:2 indicating 72% exposure, 1:2.5 indicating 73% exposure, 1: 4 indicating 77% exposure and 1:3 indicating 78% exposure. Therefore, it could be said that an ideal aspect ratio of 1:1.7 existed for the wide range of ratios from 1:1-1:4. In conclusion, the thermal comfort of the proposed building could be optimized by applying the aspect ratio “1:1.17” of cylindrical/cuboidal form to reduce the effect of west and south solar radiation. It is recommended that prospective designers should go beyond only orienting buildings on east-west axis, rather, effort to experimentally explore different aspect ratios should be considered for befitting alternative.

vii

Title page………………………………………………………………………………………………………………… i

Declaration……………………………………………………………………………………………………………….ii

Certification… ……………………………………………………………………………………………………….iii

Dedication ……………………………………………………………………………………………………………….iv Acknowledgements…….….. ………………………………………………………………………………………v

Abstract …………………………………………………………………………………………………………………..vii Table of Contents ……………………………………………………………………………………………………..ix

List of Figures…………………………………………………………………………………………………………xv

List of Tables…………………………………………………………………………………………………………xviii

List of Plates……………………………………………………………………………………………………….…xix

List of Appendices……………………………………………………………………………………………………xx

Abbreviations, Definitions, Glossary and Symbols………………………………………………. xxi

1.0 INTRODUCTION………………………………………………………………………………………………. 1

1.1 Background to study…………………………………………………………………………1

1.2 Problem Statement………………………………………………………………………………………...…… … 4

1.3 Aim and Objectives ………………………………………………………………………………….. …4

1.4 Research Questions……………………………………………………………………………………..………5…

viii

1.5 Scope……………………………………………………………………………………………………………….5

1.6 Justification………………………………………………………………………………………………………6 2.0 LITERATURE REVIEW ………………………………………………………………………………..7

2.1 Thermal Comfort Conditions……………………………………………………………………………7

2.1.1 Comfort zones of hot-dry regions………………………………………………………………………8

2.2 Energy Conservation in Telecommunication Office Building……………………………..9

2.3 Performance of Building Forms in Enhancing Thermal Comfort ………………………10

2.3.1 Thermal performance of a Building’s Volume to Surface Area Ratio (V/S)………….10

2.3.2 Relationship of Aspect Ratio (Width to length ratio) and Solar Radiation…………11

2.3.3 Thermal Response of Building Envelope…………………………………………………………….11

2.3.4 Relationship of Relative Compactness to the Cardinal Points ………………………………18

2.3.5 Effect of Self – Shading of Building Forms ……………………………………………………….22

2.4 Summary of Findings from Literature Review………………………………………………….24

3.0 METHODOLOGY …………………………………………………………………………………………..27

3.1 Research Design/Approach………………………………………………………………………………..27

3.1.1 Experimental/Case study Design………………………………………………………………………..27

3.2 Instruments of Data Collection…………………………………………………………………………28

3.2.1 ECOTECT (ECOTECT Version 11)………………………………………………………………….28

3.3 Criteria for Selecting Simulated Building Forms …………………………………………………..29

3.4 Dependent and Independent Variables…………………………………………………………………30

3.5 Procedure for Data Collection (Parametric Analysis)……………………………………………..31

3.6 Simulation inputs and assumptions ……………………………………………………………………..32

3.6.1 Analysis of Internal Heat Gain …………………………………………………………………………..32

3.7 Characteristics of Tropical Hot-dry Climate………………………………………………………33

3.8 Method of Data Analysis …………………………………………………………………………………..33

4.0 DATA ANALYSIS AND PRESENTATION………………………………………………………34

4.1 Case Study ……………………………………………………………………………………………………..34

4.1.1 Case Study I : National Communication Commission (NCC). ……………………………….34

4.1.2 Case Study II: NITEL Headquarters, Abuja………………………………………………………..37

4.1.3 Simulation Input Information …………………………………………………………………………….39

4.2 Thermal comfort conditions and comfort zone parameters for the simulation…….40

4.3 Analysis of Energy Consumption of the Building Forms ……………………………………42

4.4 Analysis of incident solar insolation on varying surfaces of cube and cylindrical

forms with varying aspect ratios ………………………………………………………………………44

4.5 Total Incident Solar Insolation on the Combined Exposed Surfaces for Overall

Orientations…………………………………………………………………………………………………….49

4.6 DISCUSSION OF FINDINGS ……………………………………………………………………………53

5.0 DESIGN PRELIMINARIES ……………………………………………………………………………56

5.1 General Climate Characteristics ……………………………………………………………………..56

5.1.1 Temperature ……………………………………………………………………………………………………57

5.1.2 Relative humidity ……………………………………………………………………………………………58

5.1.3 Sunshine ………………………………………………………………………………………………………..59

5.1.4 Rainfall ………………………………………………………………………………………………………….59

5.2 Site Selection Criteria ………………………………………………………………………………………60

5.2.1 The proposed site ……………………………………………………………………………………………65

5.3 Site Analysis ……………………………………………………………………………………………………..66

5.3.1 Topography …………………………………………………………………………………………………….66

5.3.2 Vegetation ……………………………………………………………………………………………………..67

5.3.3 Services / Infrastructure ……………………………………………………………………………………67

5.3.4 Climate ………………………………………………………………………………………………………….67

5.4 Summary of Site and Surrounding Analysis ……………………………………………………..68

5.5 Design Inferences from the Site Analysis ………………………………………………………….68

6.0 DESIGN REPORT …………………………………………………………………………………………69

6.1 Design brief …………………………………………………………………………………………………….69

6.2 Functional flow chart ……………………………………………………………………………………….70

6.3 Spaces of the technical staff area……………………………………………………………………..71

6.3.1 Network operations room:………………………………………………………………………………..71

6.3.2 Call centre department: ……………………………………………………………………………………71

6.3.3 Contact centre department:…………………………………………………………………………………72

6.3.4 Communications centre department:…………………………………………………………………..72

6.3.5 Information security operation department: ………………………………………………………..72

6.3.6 Geographical Information System (GIS) room: …………………………………………………..73

6.3.7 Interactive Voice response (IVR) room: …………………………………………………………….73

6.3.8 Transmissions room …………………………………………………………………………………………73

6.4 Bulk schedule and space grouping …………………………………………………………………..73

6.5 Schedule of Accommodation……………………………………………………………………………..77

6.6 Design Philosophy ……………………………………………………………………………………………81

6.7 Main Buildings in the Centre……………………………………………………………………………83

6.7.1 The telecommunication office………… …………………………………………………………………83

xii

6.7.2 The vocational/technical training unit/restaurant …………………………………………………83

7.0 CONCLUSION AND RECOMMENDATION……………………………………………84

7.1 Conclusion …………………………………………………………………………………………………….84

7.2 Recommendation …………………………………………………………………………………………..85

7.3 Contribution to Knowledge …………………………………………………………………………..86 REFERENCES …………………………………………………………………………………………………….87

1.0 INTRODUCTION

1.1 Background to study

Telecommunication office buildings are essential to the economy; however, they are also significant consumers of energy required to maintain thermal comfort. (Creamer Media Reporter, 2015). Thermal comfort is recognized as a key parameter for healthy and productive workplaces, some of which are found in telecommunications building. At the same time, lowering energy use in commercial building is vital if a significant reduction in greenhouse gas emissions is to be achieved. Traditionally thermal comfort has been achieved at the expense of significant energy use for heating and/or cooling (Ismail, Jusoh & Makhtar, 2010). In a major study, Taylor, Fuller & Luther (2008) found that a well- designed building should be able to provide good thermal comfort, while simultaneously having low energy consumption.

The thermal conditions of an office environment are very important with respect to the productivity and success of that office. The excessive cost of energy used to attain occupants‟ comfort could lead to decrease in profits productivity, and if this effect is lasting for a longer period, it could be detrimental to offices‟ productivity. (Ismail etal.,

2010).

Studies have shown that employee satisfaction with the thermal comfort of their workplace plays a significant role in both employee retention and productivity. One study even revealed that employees consider workplace comfort second only to compensation in terms of benefits (American Society of Interior Designers). Since telecommunication office workplaces and cooling need expand, it is as a result of the use of servers and other telecommunication equipment that has spread widely in our society, and their importance as a social infrastructure has been increasing. However, the operation of telecom equipment generates a large amount of heat and requires year-round air conditioning, so there is a strong demand for reduced power consumption of air conditioning systems. (Yosuke, 2014).

Also, in order to stress the widespread of telecommunication sector that brought about office workspaces and cooling need demand, Olusoji (2000) stated how the Nigerian Telecommunication limited (NITEL) was created from a merger of the Nigerian External

Telecommunication and the Telecommunication Departments of the defunct Post and Telecommunication in 1985. Olusoji (2000) further asserted that the main objective of establishing NITEL was to harmonies the planning and co-ordination of internal and external telecommunication development and provide accessible efficient and affordable services.

However, almost 20 years or more down the line the Nigeria Telecommunication Limited had roughly half a million (500,000) lines available to over 100 million Nigerians (Nigeria Business Information, 2005). From a bit above 500,000 NITEL fixed wire line and mobile subscriber in 2001, the industry grew to over 7 million subscribers in 2004; in December 2008, the subscribers in the market grew to 62.99 million, an addition of 22.59 million subscribers in 2008 alone represented 56% annual growth rate. Recent figure as at January 2009 put the subscribers‟ base at 64.16% while G.S.M subscribers are in the range of 57 million, CDMA subscription in Nigeria grew from just 380,000 in 2007 to more than 6 million at the end of 2008. (Nigeria Business Information, 2005).

From the above statistics, it is evident that growth in the telecommunication industry in Nigeria is increasing which in turn requires increase in the number of office facilities as thesame, while putting into cognizance an energy conservation approach in their design as a result of energy they require on air-conditioning.

As a consequence of this, building form was adopted as one of the important design parameters that affect the cooling energy required to attain occupants‟ comfort in a buildings, according to (Erdim & Manioglu, 2011) . Also, Study by (Chia, Mohd, & Dilshan, 2007) in tropical hot-humid region in Malaysia shows that different geometrical forms have the ability to react to thermal comfort differently, due to differences in their geometrical characteristics. Studies by Philip & Alan, (2014) reported that aspect ratio could affect incident solar radiation on the form. Ratti, Raydan, Steemers (2003) asserted that in order to achieve good thermal comfort, it is noted that during hotter periods, the sun has a high solar angle thus there is need for maximum shading and minimum exposure while during colder periods the sun has a lower solar angle indicating no need for cooling. Ratti, et.al (2003) further postulated that a building form can possess good thermal properties if it has a low exposed area on maximum incident solar radiation in hotter periods and high exposed area on minimum incident solar radiation in colder periods. This study aimed at examining different aspect ratios of building forms in hot dry region and attempts to suitably enhance thermal comfort, within a large office workspace with minimum amount of energy by reducing heat gain into the building during hotter periods and increasing heat gain into the building during colder periods. Although previous researches have determine the effect of different building forms on energy consumptions in different climatic region, but there are limited study that have investigated the role of

aspect ratio of building forms on energy required for thermal comfort specifically in hot- dry climate of Nigeria.

Therefore, primary design parameters of building should be developed as providing the climatic comfort conditions and minimum energy consumption during the construction and use of the building. Building form is one of the important design parameters affecting the heating and cooling energy consumption in the building.

1.2 Problem Statement

Thermal comfort within the modern office (especially those with large workspaces such as telecommunications office buildings) is determined by air conditioning both centrally for the whole building, and locally at room level by the occupants. Air conditioning systems are typically optimized during extreme summer period in hot dry regions. These air conditioning systems require huge amount of energy to attain occupants comfort . This results in unnecessary energy consumption.

It is in line with this that it is significant to provide an optimum architectural approach in the design of buildings with large workspaces that will reduce such effect by exploring different building forms, from which the essential one will be applied in reducing cost on cooling for telecom buildings in hot-dry climates of Nigeria.

1.3 Aim and Objectives

The aim of this research is to investigate the aspect ratio of suitable building form that will reduce the cooling demand required for occupants thermal comfort in a

telecommunications office building in a hot-dry region.

111v

The research intends to achieve the aim above through the following objectives;

To study the thermal comfort conditions and comfort zones in hot-dry regions.

To study the effect of various building forms toward enhancing thermal comfort.

To optimize the studied building forms with different aspect ratios using solar exposure with a computer simulation. iv. To demonstrate the research findings in the design of a telecommunications office building in Maiduguri, Nigeria.

1.4 Research Questions

This research seeks to answer the following questions:

Which building form reduces energy demand on thermal comfort for a large workspace office building.
In what ways can the research findings be applied in the design of a telecommunication office building?

1.5 Scope

This research is focused on the architectural aspect of telecommunication office building design in hot-dry region, Maiduguri. However, this study will only check and compare different building forms and the extent to which energy demand to attain minimum comfort level could be reduced in such way. And not on the technology aspect which has to do with the energy required to run telecommunication equipment.

111v

1.6 Justification

According to a report from the International Center for Investigative reporting (ICIR),

(2015) which stated that Switzerland has promised to partner with countries affected by Boko Haram insurgency in reconstructing ravaged areas and displaced persons. Among the facilities to be reconstructed as noted by the government are telecommunication facilities which have been completely destroyed and require reconstruction and replacements in Maiduguri.

To further justify the reason why telecom building must be undertaken in this research, another report by the African Business Central (ABC), (2014), noted that Nigerian government makes progress in latest attempt to privatize incumbent Telco and its mobile unit Mtel. Investment vehicle National Telecommunications Commission (NATCOM) has emerged as the successful bidder for Nigerian incumbent Ntel and its mobile unit Mtel.