The implementation of passive cooling into office buildings are becoming increasingly common due to a wide range of factors including the damage caused by an office buildings energy consumption, operation on the environment, increasing electricity prices, change in the climate conditions, worsening of heat islands, increase in greenhouse effect and so on. Passive cooling involves the incorporation of techniques with the intention to treating the internal environment of an office building in a natural means without the use of mechanical means, to improve the buildings performance globally. A range of passive cooling options have the potential for reducing the operational energy consumed by a building and improve the level of the internal comfort experienced by the user. This review presents the results from case studies on office buildings. The main aim of the case study was to establish the level of thermal performance of an office building and how the implementation of passive cooling techniques can greatly improve its performance. The aim of the literature review was to develop an understanding of passive cooling techniques that may be used to office buildings to combat energy consumption and improve occupant comfort. The results for the case study research conducted indicate that there are a number of passive cooling techniques into an office buildings external façade, shading, thermal insulation and natural ventilation through the use of night ventilation and window operation. It is considered with the exception of reflective roof coverings and the use of passive cooling will result in an increase in the comfort levels noticed by a buildings occupants TABLE OF CONTENTS ABSTRACT INTRODUCTION AIMS & OBJECTIVES LITERATURE REVIEW INTRODUCTION BACKGROUND REDUCING ENERGY CONSUMPTION IMPROVING INTERNAL COMFORT CONDITIONS REGULATION AND LEGISTRATION ON SUSTINABILITY THE IMPACT OF AIR-CONDITIONING ENVIRONMENTAL ECONOMICS INDOOR AIR QUALITY PASSIVE COOLING TECHNIQUES NATURAL VENTILATION GLAZING THERMAL INSULATION SHADING ADVANTAGES OF PASSIVE COOLING CONCLUSION METHODOLGY INTRODUCTION RESEARCH APPROACH RESEARCH STRUCTURE DETAILED RESEARCH REPORT METHODOLOGY IDENTIFY A RESEARCH PROBLEM WRITE A LITERARURE REVIEW CONCEPTUALISING A RESEARCH STRATEGY TOOLS FOR DATA COLLECTION COLLECTION OF DATA & PROCESSING DATA WRITING THE RESEARCH ANALYSIS RESEARCH CONSTRAINTS SUMMARY
An review into the use of passive cooling options for office buildings is the proposed topic of research, It is an area of great interest as it has be used abundantly with the infrastructure of today’s society, and can play a vital role from the buildings we work in to the dwellings we habitat. By implementing these types of solutions we can reduce a buildings energy consumption, reduce the use of mechanical cooling systems (air conditioning) and reduce our carbon footprint, which is directly linked to global warming and climate change. During the last 70 to 80 years, In most populated cities around the world, there has been a substantial increase in the construction of new buildings, of which would require massive amounts of energy to run all year round. During hot climate conditions (summer months) one specific function of a building is needed, to keep the building at a cool ambient temperature for thermal comfort to humans, typically this is achieved by using air conditioning. Air conditioning systems are a readily available product, where a comfortable thermal environment is achieved at the push of a button, it can be installed in virtually any building, even buildings that do not retain heat well, that have a poor thermal design. With this type of system comes vast financial expenditure to install the units, and the running cost of the plant needed to power the air-conditioning units. Further consequences are:
- Huge amounts of wasted electricity
- Air pollution
- Cost of annual maintenance
- Cost of manufacturing
- installing and maintaining the cabling,
- Increases the capital cost of buildings.
With the need to generate more and more energy to power mechanical cooling systems, we increase our carbon footprint and aid in global warming which in turn changes our climate. It is expected in the UK alone that over the next 50-60 years we would have seen an increase of temperatures of 3-6 ºC. This will result in warmer summertime months than of past years ranging from 30-35 ºC and could see many existing buildings suffer from overheating. see life cycle below: Therefore the potential of advances in passive cooling techniques can ultimately reduce:
- Energy demand
- Cooling loads
- Greenhouse gas emissions
- Avoid overheating of new and existing buildings in warm months
As consequence of all these contributing factors, the following the research objectives, aims were developed.
The main aim of this research is to investigate the effectiveness of passive cooling options for office buildings. To achieve this, various case study’s, article journals and published technical book were research and reviewed. In addition talks with a range of industry professionals, from various background disciplines was also carried out. This research was completed with an aim of finding out an understanding of the thermal performance of office buildings through the comparison of the internal thermal environment experienced to thermal comfort standards. The aim of the research is supported by the objectives listed below:
- To find passive cooling options that may be applicable for office buildings.
- To examine the passive cooling options in regards of reducing the need for mechanical air conditioning and the energy consumption required to operate.
- To compare the indoor climate level quality using passive cooling techniques instead of using mechanical techniques.
SCOPE OF RESEARCH
This dissertation is structure in the following chapters; INTRODUCTION The introduction provides the knowledge and problems related to the research topic, identifies the aims and objectives of the research and provides an overview of the structure of the dissertation. LITERATURE REVIEW The literature review, reviews the available and current literature relative to passive cooling of office buildings, which forms the foundation of the research. The body of knowledge has been found from journal articles, books and websites related to the topic.It discusses the concept of energy consumption of an office building in the operational phase and the various passive cooling techniques available. RESEARCH METHODOLOGY The research methodology identifies and discusses the methodology adopted for this dissertation, it is based upon research models from Guide to undergraduate’s dissertations, London Southbank University, and various similar research models. It is structured to identify the process for the researched to adopt. The research followed the process of formulating a problem, write a literature review, conceptualising a research strategy, identify the tools for data collection, the collection of data & data processing and finally examine and summarise findings. ANALYSIS OF RESEARCH The analysis research SUMMARY AND CONCLUSIONS
This literature review presents the body of knowledge relative to passive cooling techniques. Providing the foundations for this research paper. The literature review was completed with the aim of establishing:
- An understanding of historic background knowledge on passive cooling;
- An understanding of reducing energy consumption in office buildings, and improving internal comfort conditions;
- The effects of mechanical cooling techniques in office buildings;
- The potential outcome of implementing passive cooling techniques into office buildings
Research from review journal articles, research papers and published technical books was considered as the main base of material evidence for this research paper. To identify the most relevant data, parameters were first defined which are shown in Table 1. This was to enable the research to be specific & narrowed down the search area to a manageable amount.
|Table 1 journal articles, research papers and published technical books research|
|Search criteria used the data search:||Title / Keywords|
|Published year (onwards):||2000|
Considering only the title and key word search parameters, the data was procured on a number of web-site databases, this is detailed in Table 2.
|Web-sites used to conduct research|
Initial review of all the results were gathered, and the most relevant journals / re-search papers & technical books were consolidated into a manageable amount. From this we gathered the most relevant data for review and comparison.
Passive cooling is not regarded as new technology. Cooling is the transfer of energy from the space or the air supplied to that space, in order to achieve a lower temperature or lower humidity level than those of the natural surroundings. The developments of cooling has passed through many stages, from simple intuitive applications of natural cooling solutions such as shading, evaporative cooling and air circulation for improving the comfort sensation. As building architecture developed to become more artistic, the needs and demands of humans also changed. Well before the development of mechanical cooling solutions, many techniques were used in the design stages for providing cooling and comfortable indoor conditions. The use of these cooling techniques was not based on the understanding of the physical process, but more on the conceptual experiences. These were simple applications such as.
- Air movement through open spaces
- External and internal shading
- Appropriate arrangement of the surroundings i.e open pools / ponds & vegetation
- Use of building materials with a low conductivity of heat, i.e marble and light surface paints
Building design incorporated many essential and simple, effective principles. Large openings of the buildings can allow for ample cross air movement, which has a direct impact of a buildings cooling load. Even if the outdoor air temperature is not a desirable low temperature the air movement creates a cooling sensation as it passes over and around a human’s body. The building itself provides sufficient protection to occupants by shading the living spaces from direct solar gains. Landscaping around the building was primarily designed for the aesthetic reasons but at the same time improved the microclimate around the building, by providing shading and evaporative cooling. Extensive use of vegetation around buildings provided the necessary shading, and also absorbing large amounts of incident solar radiation and maintaining lower air temperature. Open pools, fountains, ponds and running water very popular in the historical development of architecture aesthetics, during the periods of water evaporation due to temperature increase, this will decrease the dry bulb temperature of the air, but at the same time increase the water content / moisture of the air, which will cool a buildings external shell. Painting or using Light coloured materials on the outer surfaces of a building is used extensively around the world, in traditional Greek architecture you will find the traditional picturesque white villages on main land Greece and the surrounding Greek islands. White surfaces reflect much of the incident solar radiation, thus reducing the heat transferred into interior spaces. Another effective way of dealing with the problem of high temperatures during the day has also been the behaviours reactions of people/humans. The use of certain cooler rooms in the day, physical changes made to the building, family gatherings in cooler open spaces, mid-day breaks (siester) and outdoor sleeping were ways / solutions of dealing with high temperatures and uncomfortable conditions during supper periods.
As a result of the ever increasing general population, increasing cost of fossil fuels (non-renewable sources), the price of electricity is constantly increasing. Published results have shown that the price of electricity has drastically increased by 40-50%, from a period of 1997 to 2010, and that the predicted future outcomes show increase is likely to happen again (office of energy n.d) During the past 10-15 years the commercial market position of a building has become largely influenced by is energy efficiency and sustainability within the environment . By incorporating passive cooling technologies such as night ventilation, improved insulation or improving quality of glazing, the goal of reducing operational energy and improving sustainability, can be accomplishing. The end result of reducing an office buildings energy consumption is savings in the buildings operational cost and therefore making the building economically sustainable [1 find reference].
The health and wellbeing of an office buildings occupants are largely affected by the internal comfort levels. The overall goal of an office building is to provide a pleasing and healthy location for its occupants whilst at work, and therefore the treatment of the indoor environment is required . It is not possible to meet the needs for every individual occupant’s desires. The typical needs of the buildings population is targeted through the form of a series of indoor environmental quality indicators. BSR/ASHARE standard 55P is the proposed American national standard for Thermal Comfort Conditions for Human Occupancy (may 2003) notes that an internal environment should target to satisfy 80% to 90% of the buildings occupants. Quality indicators for the indoor environment are required to achieve the thermal and respiratory necessities of building occupants whilst avoiding the build-up of pollutants / containments. (Construction innovation ISSN:1471-4175 2001). The energy consumption of buildings is very reliant upon the environmental quality criteria as perceived in BSR/ASHARE standard 55P. Indoor environmental quality indicators are presented below :
- Indoor air quality indicators (IQA)
The indoor air quality or IQA is more or less all attributes within an internal environment that have the potential to affect the wellbeing or impose health implications of an occupant . An office buildings envelope with poor levels of indoor air quality can result in discomfort, tiredness and headaches. There also the potential of developing more serious issue such as public liability for the building operator .
- Thermal comfort indicators
Thermal comfort is often linked to an occupant’s psychological level of satisfaction with the internal thermal environment of a building . The level of thermal comfort for an occupant is achieved by adhering to the following characteristics :
- Air speed: where the speed of the air flows around the internal space / shell of a building;
- Internal air temperature: the mean temperature of the internal air of a building which surrounds an occupant;
- Relative humidity: the amount of water vaper in the air
- Thermal gradient: the difference in internal air temperature as is rises in height through a building;
- Temperature time variation: the change in air temperature over a period of time;
- Radiant temperature: the alteration in temperatures from hot and cold surfaces.
Additionally personal factors such as clothing or activities of the occupants will also influence the level of thermal comfort .
Over time government bodies have seen that the need for passive cooling is every increasing, where now governments are implementing regulations and passing law’s to make buildings more sustainable, which is a major force behind the movement to increase the energy efficiency of buildings.. The UK recognises that the impact of our daily work, social practices and construction sector has a negative global effect to a sustainable environment. UK Legislation and regulation are now enhancing our environmental sustainability through the use of sustainable design and construction in the UK construction sector . The European Directive on the Energy Performance of Buildings (EPBD) took effect from 4 January 2006. A reorganising of the requirements, which will be more demanding, was approved in May 2010 and came into effect in early 2013. The EPBD aims to promote the improvement of energy performance in buildings by encouraging owners and tenants to choose energy efficient buildings when seeking new premises, and to improve the energy efficiency of buildings that they already occupy . In the UK, the EPBD was also implemented through major changes to the Building Regulations 2006 and the introduction of energy certification (DECs and EPCs) for both domestic and non-domestic properties, which directly affect the construction of new buildings . Other legislations to improving sustainability include:
- CRC – Energy efficiency scheme: the carbon reduction commitment (CRC) Energy Efficiency Scheme is a mandatory scheme. Which focuses on large public and private sector organisations, which are responsible for around 10% of total UK greenhouse gas emissions, to reduce their environmental impact ;
- EIA – Environmental impact assessments: An Environmental Impact Assessment (EIA) is the process for identifying the environmental impact of proposed developments ;
- BREEAM & the code for sustainable homes: BREEAM is the world’s most widely used system for assessing, reviewing and improving a range of environmental impacts associated with buildings. The CSH is a largely voluntary standard that acts as a pathway to Zero Carbon Homes, which are to be mandated for all new build housing from 2016 .
As we still have extensive use of air-condition units, the following problems can be directly liked to which mechanical cooling systems damage our environment and provide poor sustainability:
The expanded use of air conditioned units has seen drastic increases in electrical demand and consumption during summer time months/seasons. With the increase in electrical demand we put our national supply grids under strain to preform, and to sustain this need for more electricity comes the demand to build new power plants. Additionally we also see an increase to the consumer for the average cost of electricity per house hold, this is to cover the construction cost of new power plants and to cover the day to day running of said energy plants. Figure 2.0 Volume of UK domestic electricity and gas consumption dating 1965-2014 . Increases in electrical energy production can then be linked to the increased use of fossil fuels which power energy production plants, from this, we generate atmospheric pollution which results in climate changes. During the process to of fuel conversion we release CO2 into the atmosphere, which is a main contributor to the greenhouse effect. Typically Coal-fired plants emit 0.5kg of carbon dioxide in the form of CO2 for each kWh generated. Heat rejection during the production & operational process of air conditioning units themselves increase the occurrence of the urban heat islands. This is where the climate is modified by the heat releases and pollution of the units, thus generally producing warmer air in cities. Where research shows that summer time heat islands are of average daily intensity of 3-5°C resulting in discomfort for humans and increased air conditioning loads. Our ozone-layer weakening can be caused by the most common refrigerants of currently used air conditioning, CFCs & HFCs. This is due to leakage during manufacturing, maintenance or failure of the unit. Is had been forecast that in the UK the average annual rate of refrigerant leakage from air conditioning units is around 15%-20% of the total machine charge. It is seen that long-term alternatives to CFCs and HFCs will have zero ozone layer depletion potential (ODP), most of them will still be strong greenhouse gases.
The Installation of air conditioning units creates an additional cost on-top of the construction cost of a building. This also leads to additional costs to operate and maintain the units. Increases in peak electricity demand creates the additional requirement of power plants to satisfy the increasing needs and background costs such as the of importing of conditioning units from abroad.
The potential to increase illness symptoms such as headaches, sore eyes, dry throat and dry skin and asthma, which can also be referred to a “sick building syndrome’ are usually linked to people working in air-conditioned buildings .
Passive cooling techniques focus on using different parts of a building and the environment it is surrounded by to accumulate cooling energy. Passive cooling main objective is the removal of heat form a buildings shell through the natural process of heat rejection into the atmosphere and surrounding ground through mean of convection, conduction, radiation, and evaporation . The use of passive cooling concentrates mainly on reducing / removing unwanted internal and external heat gains of a building, using orientation, ventilation, windows & shading techniques thus generating the cooling potential and limiting the operational energy of air conditioning . INTERNAL HEAT GAINS Most properties contain multiple internal sources of heat, which is also referred to as internal heat gains. Common sources of internal heat gains are people, lights, pets, electronic appliances, cookers, washing machines, dryers, TV’s, computers, dishwasher’s, kettles, toasters, hot plates, all which produce waste heat. When you combine all of these heat generates sources, you find a huge combined generated amount of heat. Though, this is a great for winter months, for summer months not so much. These internal heat gains make properties less comfortable to work in and result in high fuel bills . EXTERNAL HEAT GAINS The sun is the major source of external heat gains and is essential to have a knowledge of the sun’s position throughout the times of the day/month & year when designing buildings and using passive cooling. Knowledge of knowing the direction of prevailing winds is also crucial. Using this knowledge allows the us to find the best orientation of the building, window positions and shading devices. The suns heat enters properties externally in a various ways, by light hitting the roof of a house, which is absorbed into the roof structure and stays buoyant in the attic of the roof, heats up the insulation and the timber framing of the roof. Sunlight hitting windows and walls, warm air generated from light hitting driveways and patios decks. This warm air heats up walls and windows of a property. Warm air can also heat a building by passing through openings in doors and window  The main elements in the passive design of a building include the following:
- Natural ventilation through the building, reducing the barriers to air paths;
- Allowing for fans to facilitate ventilation if the natural air flow is absent or ineffective;
- Incorporating channels or corridors for warm air to exit the building;
- Suitable height for the instillation glazing to provide an adequate level of ventilation whilst avoiding significant heat gains;
- Effecting shading;
- Adequate levels of insulation;
- Use of light paints / cladding to walls and roofs to reflect solar radiation (external heat gains).
Natural ventilation introduces the flow of air into a building by natural means, where air flow / movement is one of the most important aspect of passive cooling. A breeze flowing through a building at 0.5m/s will generate an effect of the internal temperature being 3-5°C lower than it actually is. Natural ventilation is a good valid consideration for implementing into a office building. Thorough the incorporation of cavity walls, louvers and canopies and many other methods, the air can be direct through the interior of the building shell with the aim of providing fresh air, enhancing the removal of hot air and reducing the perceived internal temperature, whilst in addition avoiding the build-up of pollutants . An example of this would be opening windows at opposite ends of a building where the wind is acting in a normal direction to the building face, the open window will encourage a cross flow of fresh air through the building. The cool external air can be of use to lower the internal heat gains on hot summer days . Night ventilation is an effective and energy efficient approach to improving the indoor thermal environment of a building. The approach of Night ventilation is storing the night’s coolness, when the air temperature is low enough within the thermal mass of the building to facilitate the removal of the heat within the building envelope the next day . It has been observed that the daily peak temperature within the building shell can usually be reduced by around 3-4°C through the use of night ventilation, thus showing us potential reductions in energy consumption .
A buildings envelope is the main barrier between the internal and external environment, but with buildings now incorporating more glazing to be become aesthetically pleasing, achieving a satisfactory comfort level can often result in extreme high energy consumption . Glazing within a building is required to provide a level of thermal comfort, visual comfort and balance the level of heat absorbed. Glazing within a building can be responsible for heat loss and also heat gain. Where windows are actually the most energy transmissive element for a building. Data provided in the glazing energy performance and design shows us that glazing is responsible for around 15-25% of the heat loss of a building and around 30-40% of the heat gains [check this 13]. Data also shows that a typical façade with a window accumulates around 40-50% of the façade, by reducing the window size percentage. We gain a reduction in energy consumption and limit heat gains . The best way to neutralise energy consumption through glazing is using smarter designed windows. A number of advances have been made in the glazing industry, the latest glazing technologies have been designed with the intent to minimise energy consumption. Last are the latest advances in glazing .
- Vacuum glazing
Vacuum glazing is very similar to the same principles and assembly as double glazing, where you have 2 parallel sheets of glass separated by a gas cavity. The Vacuum glass slightly differs as the gas between the sheets if glass id evacuated to low pressure, reducing the level of heat conducted . Figure 3.0 Heat transfer process for vacuum glazing .
- Spectrally Selective Coating
Spectrally selective costing, also known as Thermochromic glazing, is the use of a thermochromic coating allowing the sunlight to enter through the glazing panel to light the building whilst reflecting the heat gains away from the building, reducing energy consumption to cool the building shell .
The thermal performance of a building shell is the result of the materials properties used in the construction phase of the build. The aim of installing insulation into a property is to reduce the speed at which heat flows through conduction, convection or radiation in and out of a property. Through the use of correct insulation to roof lost spaces and walls heat gains can be prevented from entering the building and therefore reducing the internal thermal environment .
The sun transmits / radiates its heat gains through glazing, which increases the internal temperature of a building, where the internal fabrics / furnishings of a building absorbed the heat. The most effective method of reducing the impact of solar gains into a building is to stop or reduce the the direct radiation of the sun prior to it coming into contact with the glazing / building external shell . Shading is now considered a main technique to reduce cooling loads in a building. Shading of a building face can be implemented through a range of techniques which include the flowing ;
- Internal shading;
- Static or movable external blinds or louvers;
- Rolling reflective roof canvass;
- Earthern pots;
- Vegetation to the external face;
- Recesses in the external envelope of the building;
- External roller shades
Of the shading methods noted it is commonly known that the use of external shading techniques usually outweigh the use of internal shading techniques as the heat transmission is lost to the external environment, rather than to the inside of the building shell . The use of trees as a natural shading technique is an extremely effective technique for reducing heat gains into a building, the trees are to be positioned around the perimeter of the building & far enough away so that the routes do not affect the foundations of the building . Courtyards provided a cooling technique by the use of shading and night-cooling. At night the open-aired courtyard will lose heat into the atmosphere while being protected from warming effects of the night winds. The cool air stratifies at night and seeps into the surrounding rooms fo the building, thereby cooling them. In the day the air in the courtyard which is shaded by the four walls heats up slowly but remains cool until late in the evenings, by which time the night process of cooling comes into effect. Green roofs or also known as roof lawns or roof gardens have been used to reduce the rate of solar heat gains, to help maintain comfortable thermal conditions in buildings/homes. Unlike the most conventional method of using a thin layer of concrete to prevent solar gains from entering the roof, which transfers 50% of the solar energy, a green roof with equal thickness will roughly transfer 5% of the solar gains . Is has been found that windows or glazed areas of a building face with shading techniques have reduced the energy consumption to cool a building via the use of mechanical means.
The energy required for heating and cooling of buildings is approximately 6.0% – 7.0% of the total world energy consumption, this figure can drastically be reduced by 2.0% – 2.5% with the use of efficient passive cooling design. In hot climate countries energy needs for cooling can amount to two or three times those for heating on an annual basis. By using basic principles of heat transfer combined with the local climate and specific properties of construction material, passive cooling can make possible the control of the comfortable living conditions of the within the interior of general housing. Even in areas of the world where the mean average maximum temperature is around 30°C-32°C, with the use of efficient passive cooling design indoor comfort conditions can be achieved. Figure 1.0, annular increase in mean annual temperature for the London, North West England & North Scotland Regions . It was anticipated that in 2010 an increase of 8 – 9 million tons of oil equivalent per annum in total could be achieved in technical potential solar contribution, if passive cooling techniques were applied in general housing / buildings.
The Literature review has presented an overview of the energy consumed by a building through the use of mechanical means to cool. The use of air conditioning systems within an office building totals up to around half of the energy consumed to cool. Therefore there is a need to reduce the operational energy of a building through reducing the use of mechanical air conditioning systems. Passive cooling has been identified as an effective method for reducing the operational consumed of a building. Many methods / techniques of passive cooling may be implemented into an office building either at construction phase or post construction. Natural ventilation, new technology glazing, shading and thermal insulation are all viable options to have potential in the savings on operation cost to mechanical air conditioning and operational energy consumption.
The research methodology used for this report follows a structure outlined by various sources including; London south bank university & guide to undergraduate’s dissertations. The research structure used is as follows
- Identify a research problem;
- Write a literature review;
- Conceptualising a research strategy
- Tool’s for data collection
- Collection of data & data processing
- Examine and sum-up findings
This part of the research report explores every stage of the research process in detail and discusses the research found so that the main issues arising from the report are clarified.
Research methods can be categorized from a number of views;
- Application approach – Pure research & Applied Research;
- Objectives approach – Descriptive research’ Exploratory research, Correlation Research & Explanatory research.
This research report paper uses the application approach. The research technique, procedure and methods were applied to the collection of information with a view to determine the likely effect of a passive cooling technique on the operational energy consumption and internal comfort of an office building. The research approach used is a combination of descriptive, collated and illustrative research. It provides information to various methods of using passive cooling into a building from construction phase or post construction phase. It shows the relationship between passive cooling, operational energy consumption and internal comfort and it explains why the need for change to passive cooling is essential to change the operational energy consumed by an office building.
The following is the structure the research followed, it is a step-by-step process to undertaking the research report;
- Identify a research problem;
- Write a literature review;
- Conceptualising a research strategy
- Tool’s for data collection
- Collection of data through interviews and data research
- Examine and summarise findings
The structure is very simple, which was assembled from various web page sources various sources including; London south bank university & guide to undergraduate’s dissertations.
The research problem was established from the knowledge gap during the preliminary research for the current literature. The research identified a number if case studies and journals which explored passive cooling techniques, the impact of mechanical air conditioning and the impact of an office buildings energy consumption. As a direct outcome of this research finding, the problem was identified.
A literature review is the outcome of reviewing all existing knowledge of the research subject and provide the research paper with a theoretical background, guiding the subject and put it into a context which is characteristic and appropriate for the purpose of this study. The literature review process of the report involved searching for existing literature relating to the subject of passive cooling including technical books, articles, journals and information on the world wide web. After securing a range of literature a preliminary review was produced on passive cooling, reducing building energy consumption and internal comfort conditions. From this the finalised literature review was produced over the past 4-6 months, the finalised reviewed involved a process of update the review over the time period.
The research strategy is used in the paper to answer the questions validly, objectively & specifically. The aim of the research is to illustrate what procedures were used and the activities undertaken to assertion the answers to the research problem. The research strategy ensures that all the aspects of the research were undertaken and completed in the correct sequence. Making sure the report is open, accountable and provides clarity, minimising errors and bias opinions, in achieving the required ability to for this study to be carried out by another researcher. The characteristics of this report as as follows:
The research was non-experimental as it was not within the scope of the research to implement a passive cooling technique and observe the changes.
The research was retrospective as is based on the current performance of existing documented passive cooling technique used in office buildings.
The research was cross-sectional as it is aimed to enhance the current performance of an office building by way of using passive cooling techniques.
Multipole Case study research Case study research examining the thermal performance of an office building in the UK was used as the main tool for collecting data, where it was used to identified that office buildings in the UK which underachieving in both thermal mass conditions and energy consumption. The case study research allows the exploration and understanding of the complex issues from thermal mass and energy consumption. The case study will enable the report to closely examine the data within a specific context & will explore and investigate real-life results through collected detailed analysis Case studies are an in-depth examination of a case which provide a systematic way of observing the events, collecting data, analysing information and reporting the result over a period of time specific to that study. For this report a multiple case study design was adopted. Data was collected from an array of case studies on passive cooling, thermal performance and energy consumption of an office building. Advantages of adopting the case study method are:
- Examination of the data us conducted within the context of its use;
- Case studies allow for both quantitative and qualitative analysis of the data;
- Case studies help to explore and describe the dada in real life environments and explain the complexities of real life situations.
A numerous amount of case studies research papers were read in a period of two to three weeks and were generally completed at London South Bank university or the residence of the researcher. The collection of data involved preparing hand written notes & voice note for analysis of the case studies. The data processing stage involved the researcher to edit the collected raw data from notes and literature written down as well as voice notes collected to identify and rectify errors made, incompleteness and gaps. This involved comparing transcripts of the notes made and voice notes recorded The researcher processed the data for the dissertation on Microsoft word to show the analysing of the data and tables. A final summarising of the findings was produced and incorporated into the dissertation to make meaningful conclusions, from the research findings.
The researcher wrote the research analysis using a similar structure to the literature review and research instrument. The findings from the case study research were analysed and compared to the information presented in the literature review to establish common findings and differences.
The researcher acknowledges that the research was constrained due to the following;
- The building performance research was limited to one location as oppose to multiple national locations, which was due to limited time on the research;
- Information to the energy consumption cost of the case study was unavailable due to limitations of data available to the public on the web and published data;
- In the time frame it was not possible to fully analyse the cost implications of implementing passive cooling technologies;
- The researcher was limited to a time period of 10-12 weeks to carry out the research due to working in a full time demanding job and only having day release to for university studies;
- The research report was limited to 10000 words plus or minus five percent.
The research methodology adopted for the subject is based upon a 6 stage process as outlined by numerous university’s including London south bank university. The methodology adopted by the researcher was successful in providing sufficient data for analysis and the deduction of meaningful conclusions. As a result, the research methodology has been successful in satisfying the research aim and objectives and in answering the research question.
ANALYSIS OF RESEARCH
From reviewing and analysing various case studies on passive cooling techniques, the technique opted for this research dissertation was night ventilation, and its effectiveness for cooling an office building. The analysis research is structured as follows;
- Weather and building suitability;
- Cooling potential and performance;
- Building application;
- Summary of findings.
WEATHER & BUILDING SUSTAINABILITY
Of the many techniques researched from various case studies and the techniques listed in the literature night ventilation is the chosen technique as it particularly appropriate for an office building. This is due to the way an office building is used, which enables high air flow to flush out the interior at night when the buildings are uninhabited. The UK’s daily temperature range varies from medium to large.