This effort is coordinated in Europe by a compact and newly revised legislative framework (EPBD). The focus of the legislation is in the building sector, as it is one of the largest consumers of energy, both in Greece, in Europe and the rest of the world. Buildings are responsible for 40% of energy consumption, and also have a very large space to improve energy efficiency. European Union adopted Directive 2002/91 / EC to control and improve the energy efficiency of buildings, defining continuous consultation between the states and the imposition of common methodologies. This Directive provides for the energy study or inspection of buildings and their electrical installations by independent accredited experts, the auditor, with a view to energy efficiency in the identity of the building. The ultimate goal of the legislation is to achieve zero energy building (ZEB). These buildings are expected to play a leading role in energy saving.
In Greece, the first organized legislation was the ‘Energy Performance of Buildings’ Regulation (G.G. 407 / 9.4.2010). The methodology to be applied is determined by this Regulation, the Technical Guidelines of the Technical Chamber of Greece (TEE) issued and certified TEE- ΚΕNΑΚ software. In the context of this dissertation, the energy management of the main building of Athens Metro S.A. is investigated, as a case study of a typical tertiary sector building (office building), which presents significant shortcomings in the energy design, resulting in low energy performance. With the energy audit that carried out, the energy performance of this building is evaluated. The audit includes inspection of the thermal insulation, to determine the thermal characteristics of building envelope, the recording of lighting systems, all the computers, consumption in electrical appliances and equipment used in offices and recording of the HVAC systems. The methodology adopted complies with the certified ‘TEE- KENAK’ software. The purpose of the inventory is to collect all the necessary information needed to extract a firm conclusion on the energy performance and ranking of the building.
Additionally, energy saving measures which aim to improve the energy efficiency of the aforementioned building is both proposed and appraised.
Chapter 1
1.1 General
Worldwide, the reduction of energy consumption is an issue of crucial importance, due to both environmental and financial reasons. Therefore, numerous efforts are being made to drastically reduce energy consumption.
The growing demand for energy in Europe over the last few decades has caused major environmental problems. Increased scientific evidence of climate change, high energy prices, increasing dependence on imported energy and the possible geopolitical consequences of this dependence, have led the European Union to take action. In particular, almost 50% of the EU’s energy needs are served via imported energy resources. It is estimated that with the same rate of growth, this ratio will have raised up to 70%, by 2020. Another important point is that energy imports account for 6% of total EU imports, with 45% of imported oil coming from the Middle East and 40% of gas from Russia. For this reason, EU has focused on reducing energy consumption while increasing renewable energy production (RES) in order to reduce greenhouse gas emissions and achieve greater energy independence. These efforts officially started with the Kyoto Protocol where first written back in 1997. According to this protocol, the 191 countries (until 2010) have decided to reduce greenhouse emissions by 2012 to 5.2% on the basis of 1990 data. [11]
Figure 1.1: A graphic showing the reduction of greenhouse gas emissions required by the Kyoto protocol.
In January 2007, the European Commission proposed to take drastic measures, namely achieving 20% less energy consumption, 20% reduction in emissions greenhouse, and 20% share of energy from RES, as shown in Figure 1.2.
Figure 1.2: EU 20-20-20 Policy
According to the International Energy Agency (IEA), energy consumption in heating, cooling, lighting and hot water buildings accounts for more than 40% of total energy consumption and 50% of greenhouse gas emissions in Europe. The sector of tertiary and residential buildings represents the largest consumer energy, even from industry and transport. The production and use of energy is the cause of 94% of CO2 emissions, with a 45% share in the construction sector (European Commission data). Recent research actions aim at achieving improved energy efficient buildings. Achieving a 20% reduction in energy consumption by 2020, equivalent to 390 million tons of oil equivalent, will bring significant benefits for energy and the environment. In addition, the expected CO2 reduction of 20% compared to 1990 figures (equivalent to about 780 million tons) is more than double that of the EU required to reach the Kyoto Protocol. To achieve this goal, we must achieve a reduction in annual power consumption of 1.5%.
Over the years, the development of services, increasing the duration of the workers and working hours, as well as the demanded indoor comfort conditions, have resulted in increased energy consumption in buildings, such as to be comparable to the consumption of industry and transportation sections. The energy consumption in a building depends on the climate of the region, the architectural design of the building, electromechanical systems installed, but also the behavior and the requirements of its users. According to the International Energy Agency (IEA), energy consumption for the operation of electrical installations in buildings accounts for about 50% of total consumption. In particular, most office buildings account for around 1/3 of the total energy consumption of service providers and trade [1]. Increasing energy consumption and pollutants generated by the operation of buildings have resulted in increased pollution and significant deterioration of environment, causing as well as health problems in humans. Especially in Greece, fuels used primarily for the production of electricity are lignite and oil, the fuel with the greatest environmental impact. Oil is also a fuel that is not inexhaustible and consistently of high value as an imported species. Therefore, the increase in energy consumption for the operation of buildings is not only very polluting, it is also very expensive.
1.2 EU’s Building section and Legislation
1.2.1 Building section in EU
The building sector in Europe is the largest user of energy and the largest source of carbon dioxide emissions as it is responsible for 38.1% of total energy consumption, and about 28% of total CO2 emissions (Figures 1.3 &1.4).
Figure 1.3: EU-28 Energy consumption Figure 1.4: World CO2 emissions by sector.
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In recent years, there has been an increase in buildings in Europe and the rate of old buildings being withdrawn is very small, resulting in even greater energy consumption. In the field of buildings, the energy required comes from various forms (oil, gas, electricity, etc.) as opposed to the transport sector, which has almost exclusive use of oil. Based on the above, the options for interventions in the building sector are more, as there are many ways of providing energy to the building. Intervention in the construction sector to reduce energy consumption is a clear EU target not only to meet the 2020 targets but also to improve the building and comfort of its users as well as to achieve long-term climatic goals and low carbon emissions in 2050.
Figure 1.5: Sharing energy forms by sector [source: Eurostat]
One of the most serious problems faced by the global community in recent years is global warming. This is due to the hole the ozone caused by the irrational emission of pollutants from the combustion of conventional fuels (petroleum, lignite, etc.) Which emit huge amounts of CO2. The emission of carbon dioxide is mainly due to the production of electricity. As shown in Figure 2, the building sector is responsible for about 19% of total CO2 emissions from anthropogenic agents.
This area has many room for improvement in terms of savings as with the appropriate measures, the overall energy savings 2020 will reach 11%. That is, to achieve the ultimate the objective of reducing energy and greenhouse gas emissions, And the increase in electricity production to 20%, the upgrading tertiary sector is a necessary and very substantial one measure. Building-related activities are also an important part of the EU economy, around 9% of EU GDP and 7-8% of employment in the EU respectively. Therefore, apart from environmental benefits, the energy upgrading of buildings will bring new jobs and significant social and economic benefits. For the above the EU has adopted directives on energy savings in the building sector, So as to give the main impetus to the member states.
1.2.2 Legislation in EU
The European Union’s policy is to provide its inhabitants with the most energy-efficient products, low-energy consumption buildings, as well as the most energy-efficient systems overall. For this reason, the European Commission has adopted a series of measures which are on energy performance of buildings, energy performance of products, for cogeneration of electricity and heat as well as funding to achieve these objectives.
1. Directive 2002/91 / EC (16 December 2002) EPBD
[Energy Performance of Buildings Directives]:
The Directive is the legal instrument of the European Community for the rational use of energy in the building sector. The provisions cover the energy needs for Domestic Hot Water (DHW) production, for heating, cooling, ventilation and lighting for new and existing buildings. [17]. It is important to note that the EPBD does not determine the levels and the legislation for each of its members, but members must introduce those corresponding mechanisms and requirements taking into account local climatic, economic and social conditions.
The main points of the EPBD are:
• A common methodology for calculating the energy performance of a building
• Establishing minimum limits for the energy performance of new buildings but also those that will undergo a major renovation
• Regulations on energy performance certificates for new and existing buildings and regulates the publication of these certificates as well as their duration, which should not exceed 5 years.
• Regular inspections on boilers and central air conditioning units in new and existing buildings, as well as evaluation for heating installations in buildings that their system is more than 15 years old.
EPBD applies to both residential and tertiary sector (offices, public buildings, etc.). On the other hand, buildings of historic importance, buildings less than 50 m2, buildings that are not permanent residences and have low energy consumption and construction sites are excluded from EPBD. Energy performance certificates must be available when buildings are finished, sold or rented. The Directive also states that users of buildings must be able to regulate it power consumption for heating and DHW, to such an extent that it is economically advantageous. 17
2. Directive 2010/31 / EU [EPBD-Revision]
This directive is a review of the previous one and came to cover some gaps and clarify some concepts. The objections that occurred against the previous directive are:
• Remove the 1000 m2 threshold. Under the previous directive the buildings that should be renovated are only those that the surface more than 1000 m2.
• Member States should also set thresholds for techniques such as boilers and central air conditioners.
• The new directive refers to products and electrical appliances which are to be launched on the market by setting up energy efficiency measures.
It generally states that the EU Member States should adopt either at national or local level, a methodology for the evaluation of the energy performance of buildings taking into account the following:
• Thermal characteristics of the building (insulation, heat capacity etc.)
• Insulation of heating system and DHW system.
• Air conditioning installations
• Lighting installations
• Indoor climatic conditions
• The positive effect of exposure of the building in an appropriate orientation for the effect of sunshine
• The production of CHP electricity.
Member States should determine the minimum energy requirements to be displayed in a building and a methodology that will provide them with the best solution for implementing the directive. They also have the right to vary these limits according to whether the buildings are already existing or new, and depending on the function of the building (offices, factories, hospitals, etc.). The Directive also proposes the installation of smart metering devices in new and existing buildings. A very important point mentioned in the EPBD is Zero Energy Building (ZEB). By 31 December 2020 all new buildings should be buildings of virtually zero consumption while buildings housing public authorities or belonging to them are buildings with almost zero energy consumption. Member States should implement National plans to:
• The implementation as well as the exact definition of the term Zero Energy Building.
• Setting intermediate targets for improving energy performance of new buildings by 2015.
• Providing information on policies as well as on finance measures to be taken. Member States should introduce one a list of already existing organizations to promote its improvement energy performance of buildings (refreshed every three years.
•
Also with regard to the energy performance certificates of buildings, if the buildings have an area of more than 500 m2 and the building is used by Public Authorities or buildings regularly visited by the public, the Certificate must be in a prominent place [18].
3. Directive 2006/32 / EC [Energy end-use efficiency and energy services]
This directive cancels its predecessor (Directive 93/76 / EEC) and:
• It sets indicative measures, incentives as well as economic and legal frameworks so as to eliminate market barriers as well as imperfections which inhibit the efficient use of energy.
• Creates conditions for the development and promotion of a market oriented towards energy services so that they can energy saving programs and other measures implemented contribute to improving energy efficiency.
Under this directive, Member States must adopt and implement achieve a 9% reduction in energy consumption within the framework National Energy Efficiency Action Plan (NEEAP). They are also responsible for setting up independent public bodies to monitor progress. The public sector must also take action to achieve the purchase of appliances and vehicles consuming low energy and the creation of financial support sections. Another important point of this directive concerns the accounts that are paid by the residents of the Member State. To install personal counters in every consumer that can show the amount of energy consumed by each user, and the bills for the purchase should be based only on the consumption of the energy in question. [19].
4. Directive 2004/8 / EC [Promotion of cogeneration based on Demand for useful heat in the internal energy market]
The aim of this directive is to create a framework for action to promote the use of cogeneration as CHP plants can achieve energy yields of up to 90%. It is geared to two axes:
• Short-term: The directive should consolidate existing CHP plants and promote new ones.
• Long-term: The Directive should provide the appropriate framework for High-efficiency CHP to reduce greenhouse gas emissions.
Member States should review performance every four years CHP plants. They should also encourage the creation of new CHP units as well as take steps to eliminate the economic weaknesses that prevent them from being promoted. [20].
5. Directive 2010/30 / EU [Energy consumption directive And other resources of household appliances with labeling and Providing uniform product information]
This Directive refers to products which have a direct or indirect influence on energy consumption and need to put it into practice of 20 July 2011. This Directive repeals Directive 92/75 / EEC. Suppliers have to label the products they produce, indicating the energy consumption of the product, a brief description, the results of the calculations and the energy classification of the product.
(Ranging from A to G, with G the worst performing and A +++ the best efficient). [21]
6. Directive 2009/125 / EC [Directive establishing a framework for the setting of eco design requirements for energy-related products]
The factors that are related to whether a product is energy-friendly to the environment depend on all phases of its design (extraction of raw materials, construction, distribution and transport, installation and maintenance, use, recycling). That is why the EU requires all products marketed to be CE marked (Conformite Europeene in French). If the product does not meet the criteria set by each Member State, it must prohibit its entry into the market. [22]
7. Decision 2006/1005 / EC [Addition Agreement between the US and the EU Labels in office equipment]
This directive concerns office equipment. The EU together with the US signed agreement that office equipment such as computers, printers, faxes, etc. should bear the Energy Star sign that means they have low energy consumption. [23]
8. Directive 2000/55 / EC [On Energy Efficiency Requirements for The ballasts for the lamps Fluorescence]
This directive concerns the installation of artificial lighting in the building. In particular, through the SAVE program, the European Commission encourages the use of ballast in lighting fixtures with a view to higher efficiency and lower CO2 emissions. All fluorescent lamps include ballasts which must be CE marked. [24]
1.3 Greek Building sector and Legislation
1.3.1 Building section in Greece
The European Commission has recently introduced Directive 2010/31 / EU on the Energy Performance of Buildings (Recast of Directive 2009/91 / EU) and Directive 2012/27 / EU on Energy Efficiency. These two Directives underline the importance of the energy upgrading of buildings and the importance of long-term investment considerations for the renovation of the building stock. The EU’s overall environmental and energy targets are summarized in the known 20-20-20, ie the 20% reduction in greenhouse gas emissions, the penetration of RES in the energy balance by 20% and 20% energy savings by 2020. In the Commission Communication of July 2014, the EU is finally proposing the introduction of a corresponding 30% energy savings target by 2030, and its overall 2050 objective is to reduce greenhouse gas emissions by 2050. 80-95% compared to 1990 emission levels, with buildings being crucial to achieving this goal.
The building sector (domestic and third sector) corresponding to a high percentage of total energy consumption, as shown in Figure 1.5, representing 45% of domestic consumption for the year 2012.
Figure 1.5: Data source EUROSTAT, 2014, Energy balance sheets 2011-2012, Statistical Books.
Also from Figure 1.6, which shows the distribution of CO2 emissions per energy sector, it appears that the share of household and tertiary sector accounts for 10% for the year 2012. Similarly very high is the percentage of the electricity consumed in the country’s buildings.
Figure 1.6: Data source YPEKA, 2014, Annual inventory submission of Greece under the convention and the Kyoto protocol for greenhouse and other cases for the years 1990-2012
According to Figure 1.7, 65% of the electricity consumed in Greece in 2012 relates to household (36%) and tertiary sector (29%) according to Public Power Corporation (ΔΕΗ) records.
Figure 1.7: PPC SA, 2014, Financial Results for the year 2013
Greece’s first effort to save energy in the building sector appeared in 1979 with the Thermal Insulation Regulation of Buildings (TIR). According to a survey of the Hellenic Statistical Authority (ELSTAT 2001), 74.6% of the Greek building stock was constructed before 1980, before the TIR (Figure 4). More specifically, you estimate that only 10% of the buildings have full insulation, 20% have poor insulation and the remaining 70% have no insulation.
Figure 1.9: ELSTAT 2001, Hellenic Building Storage per year construction.
In view of the above, the goal is to gradually coordinate the upgrading of the building stock, so that in 2050 all buildings will have high energy efficiency and ideally zero and / or minimal energy consumption coupled with maximum exploitation and integration of renewable energy sources.
1.3.2 Legislation in Greece
Greece as a member of the European Union is participating in its upgrading building sector in order to reduce energy consumption. The European Commission has made it clear that Member States will adopt their own directives taking into account local climatic, economic and social circumstances. Thus KENAK was established (Building Energy Regulation Improvement). As mentioned above, Greece’s first effort to save energy in the building sector was made in 1979 with the building Thermal Insulation Regulation (TIR) and then with its recommendation of the Regulation for Rational Use and Energy Saving (KOHEE).
1. Thermal Insulation Regulation (TIR)
• It had the primary o
bjective of reducing heat losses from the building shell so that the heating requirements of the building were minimized.
• Did not formulate requirements for existing buildings.
• Required calculations based on:
a. Separating the country into 3 climatic zones
b. Using the thermal conductivity table of materials
c. The use of a panel of thermal window frames.
2. Regulation for Rational Use and Energy Saving (KOHEE)
• It is geared to limiting CO2 emissions by setting measures and conditions to improve the energy performance of buildings.
• It contained policy measures to improve energy efficiency buildings and the microclimate.
• Introduced concepts and institutions to promote rational use and management of energy resources and use of RES, improvement manufacturing quality, etc., which are part of its principles sustainable design and ecological building.
3. Building Energy Regulation Improvement (KENAK)
The purpose of this Circular is to frame the framework and lay down minimum requirements for upgrading the energy performance of buildings. This is the implementation of Law 3661/2008, which was adopted for the purpose of harmonizing the Greek legislation with Directive 2002/91 / EC. KENAK is the first comprehensive effort on the Greek side to identify all the parameters that affect the energy performance of a building. In particular, it focuses on reducing the consumption of conventional energy for heating, cooling, air conditioning, lighting and hot water production (DHW). It refers to techniques such as shell energy design, efficient building materials to be used, electromechanical installations, RES and cogeneration of electricity and heat (CHP). The methodology for calculating the energy performance of buildings is reviewed at regular intervals. In order to make the study feasible, technical instructions were issued by the Technical Chamber (TOTEE), which contain information on the climatic conditions of the area, analysis of the calculation for the energy inspection as well as minimum and maximum values to be presented by the various materials and The equipment of the building. For the need of the energy study of the building, the TEE software was created, whose predecessor is EPA-NR, The analysis of TOTEE and the software will be presented later.
For this purpose, KENAK states:
• A methodology for calculating the energy efficiency of buildings.
• Minimum requirements for energy efficiency and categories for the energy classification of buildings.
• Minimum specifications for architectural design are defined of the buildings, the thermal characteristics of its structural Shell elements, the specifications of the E / M installations.
• The content of the study on the energy performance of buildings is defined the form of the building energy performance certificate is defined.
• The procedure for energy inspections of boilers, heating and air conditioning.
According to article 4 of KENAK, the energy performance of buildings determined on the basis of a methodology for calculating consumption primary energy containing at least:
• The use of the building, the desired indoor environment conditions, the operating characteristics and the number of users.
• Climate data of the building area.
• The geometric characteristics of the building shell components in relation to their orientation and characteristics of the internal structural components.
• The thermal characteristics of the structural elements of building shell.
• The technical characteristics of the space heating installation, cooling / air-conditioning installation, hot water usage installation, lighting installation.
• Passive solar systems.
• The reduction of the calculated final fuel consumption to primary is done using the coefficients.
KENAK also defines a reference building, which has the same geometry as well as the same orientation as the building in question. In the next chapter there is a full energy study to the office building of STASY SA as well as analysis of the reference building. With KENAK, Greece laid the foundations for achieving buildings that consume as little energy as possible.
1.4 Aims of the Thesis
The purpose of this diploma thesis is to implement the revised Energy Performance of Buildings Directive (EPBD) at the main office building of STASY SA. In this paper, the method and the interventions applied to the building are presented in order to minimize the energy consumption. It also presents assessments of these interventions, based on environmental and economic benefits. In order to assess the energy performance of the existing building, an energy study was carried out with the TEE software, which is in line with the KENAK. In the present work, we analyze the software as well as the methods of calculating the geometric characteristics and systems of the building with the methods mentioned in the technical instructions of the Technical Chamber of Greece.
Chapter 2
Literature review
2.1 General
Nowadays, it is scientifically proven that energy efficiency of most existing buildings is burdensome for the environment. For this reason, the control of energy and then the study for improving the energy efficiency of an existing building is absolutely necessary. Several studies have been conducted to evaluate the energy efficiency in office buildings from the early design phase. The bulk of the literature in the field of building renovation is to minimize energy consumption and reduce CO2 emissions is mainly focused on defining scenarios on economic issues and the cost-effectiveness for both residential and office buildings.
The study of Santamouris & Dascalaki (2002), selected ten buildings located in different climatic zones of Europe, which houses offices. For each one of these buildings an exhaustive energy audit was performed. Additionally, the observations recorded by monitoring bodies were considered, specific experiments were performed and all proposed renovation scenarios were evaluated. The final deliverables from this study include: case studies which show representative renovations in high quality offices in different countries of Europe. The assessment methodology adopted, classifies buildings housing offices on the basis of their energy efficiency, CO2 production, internal thermal and visual comfort. The technical and economic potential for energy savings from selected scenarios are evaluated along with energy efficiency criteria and best practice methodologies which take into consideration the integration of renewable energy in office buildings.
In the publication of Triantis, Morck, Erhorn, & Kluttig (2003), a comparative analysis of 25 case studies regarding environmental renovation of educational buildings in 10 different countries in Europe and the United States was presented. The analysis includes cost factors, environmental benefits, energy savings factors, guiding design lines, user’s c
omments and beneficial consequences from any conversion that took place, during the renovation in case studies selected. The data collected used to develop an online tool called “energy concept adviser”. The conclusions derived from this analysis is that the integration of the architectural features of the building to be renovated, both on premises and in terms of the forming materials, is essential to the successful integration of environmental renovation strategies in educational buildings. In addition to energy savings, reduced environmental impact and enhanced interior climate, integrated projects include better use and evaluation of improved spaces in or around the building increase the participation of students and teachers in the system to achieve high environmental standards.
The publication of Asadi, Silva, Antunes, & Dias (2011), provides a mathematical model of optimization of multiple criteria, which provides assistance in the process of evaluating technology options for building renovation. The aim is to minimize energy use in a cost effective manner, while meeting the needs and requirements of users. The results from the application of the model in an existing house demonstrated the potential of this methodology to indicate the correct strategies for renovating buildings and enhance the applicability of this approach.
Rey (2004) introduces the publication of multi-criteria strategic assessment methodology for building renovations. According to this method, three basic communication strategies are identified:”substitution strategy” “stabilization strategy “and” dual-skin façade strategy “. This estimate is based on specific criteria, which are directly related to the three pillars of sustainability: environmental, sociocultural and economic criteria. The application of this approach has been validated in three case studies on factors that are representative of three different architectural periods. As evidenced by the results of the three case studies, the method developed can be a tool to aid decision making. Furthermore, it offers an efficient possibility of comparing the degree of efficiency of different renovation strategies.
Using a simulation program, Al-Ragom (2003), demonstrated that it is possible to save energy in existing homes and thus is possible to increase the national revenue of Kuwait, if renovation scenarios are implemented effectively. The study presents the results from fifteen different renovation scenarios which include insulated roof and walls and modification of glass. From this study emerges that by selecting the appropriate scenario and applying it to 42.403 old houses in Kuwait, it is possible to save 3.25 million MWh per year, and estimated that in ten years the government will have to reduce costs by $ 577 million for energy efficiency.
The study of C. A. Balaras et al. (2007), includes an overview of the residential building stock in the EU with particular reference to Greek buildings. The aim of the study was to calculate the benefits and determine the priorities of energy saving strategies in buildings in order to reduce CO2 emissions. Specifically, they applied 14 ECMs (energy conservation measures) in existing buildings of different climate zones, which need renovation in order to reduce CO2 emissions. The 14 ECMs include: thermal insulation of external walls, insulation of the roof, openings fillings, double-glazing application, maintenance of central heating, replacement of inefficient burners with efficient liquid fuel or gas burner devices, installation temperature control systems for heating systems, installation of external blinds, installing ceiling fans, installing solar panels for hot water heating, installation of energy-saving lamps. These scenarios and their impact on reducing CO2 emissions were assessed and so the best ECMs emerged. These are: wall insulation (with 33-66% energy savings and 3573, 6 kt CO2 reduction), filling openings (16-21%, 1712,2 kt), installation of double glazing (14-20%, 1539,2 kt), maintenance of central heating boilers (10-12%, 951,4 kt) and installation of solar collectors for domestic hot water (50-80%, 2709,7 kt). Similar conclusions were reached by the study, both of Amstalden, Kost, Nathani, & Imboden (2007), resulting from energy upgrading investments in homes in Sweden, as well as Kragh & Rose (2011) for homes in Denmark.
An alternative solution could be given to the problem of high energy consumption in the building sector which is the adoption of bioclimatic principles in the process of renovation of existing buildings. The bioclimatic design is the design of buildings in interaction with the environment and attempts to redefine the principles of architecture and guidelines based on harmonious natural environment and human coexistence. The use of renewable energy sources, in particular the free solar energy for heating and natural lighting of buildings, cool winds for naturally cooling them, thus restoring to a large extent, the disturbed balance between the building and the natural environment (Technical Chamber of Greece, 2011). The bioclimatic design, which, in fact, is a vital part of the overall objective of the renovation of old buildings, is limited only by the design part of the renovation. The benefits of this process will be huge.
Krstic (1998) mentions in his article that the bioclimatic rehabilitation of existing buildings can bring significant amounts of energy savings. The study examines some corrective measures in apartments located in Belgrade. Close balconies and building lofts for housing, resulting in an efficient and cost-effective increase in living space and improvement of living conditions. In their study, Cabral & Chalfoun (1998) focus on the case of renovation of an old building in Portugal, within the framework approaching sustainable construction. They attempted to improve the external microclimate of the building to reduce the cooling load required during the summer indoor building. At the same time, they have adopted strategies that were inside the building which included the application of double glazing and design rooflights taking measures for their nighttime protection and their sun protection with the extension of the roof. From the implementation of these strategies, the cooling load can be reduced by 71% while the heating load by 9%. For the exterior of the building suggested the installation of a passive cooling system in order to modify the conditions of outdoor space and thereby to improve the conditions in the interior of the building. Specifically installing cooling towers and shading systems provide sun protection in an outdoor patio that works as a summer restaurant. According to calculations, reducing the temperature in the outdoor patio, by the presence of the cooling tower, reaches 8°C.
According to a study presented by Patania, Gagliano, Nocera, & Galesi (2006), the energy consumed for heating the Kore University lecture hall, can be reduced by 65% with the application of passive solar greenhouse system. The study of Zain-Ahmed, Sayigh, Surendran, & Othman (1998), deals with the application of bioclimatic map, of bioclimatic psychrometric map, of Mahoney tables and possible control zones, with a view to determining the appropriate strategies for achieving internal comfort conditions. The study area was the Klang Valley in Malaysia, and the most appropriate strategies culminating related natural ventilation, shading and drying. The basic design principles that the building meets the concept of bioclimatic design are:
1. the building acts as a natural solar collector in winter, with proper positioning, proper shape, appropriate size and orientation of the openings, and with appropriate internal structure,
2. the building to act as heat storage, providing protection from cold winds while thermal protection (insulation),
3. the building acts as a heat trap (thermal mass), and
4. the building to act as natur
al cooling storage in summer, with a choice of bright coatings for exterior surfaces, thermal insulation and natural ventilation.
Since ancient times, as seen through the writings of ancient philosophers, the use of land properties, air, sun and water in the housing construction process, was very important, which in Socrates (the memoirs of Xenophon 430-435 B.C.) ideal residence is one that offers warmth in winter and coolness in summer (Chegkazi, 2009). Indeed a building which has been designed based on the principles of bioclimatic design has many advantages for both the environment and for its users, such as reduction of greenhouse gas emissions and conserve natural resources, save energy for heating up to 60%, and up to 30% for lighting, improving indoor air quality, favorable microclimate with proper planting and materials, improved hygiene and thermal comfort (Cyprus Energy office, 2010).
Drawing examples from the traditional buildings in the world, found that indigenous wisdom that hide within these buildings, and applied knowledge of craftsmen whose experience was based on the observation and interpretation of nature, is what must now be regenerated with the term “bioclimatic design” adding technological development. Typical examples of energy efficient traditional buildings are the ‘built with mud’ villages in Pueblos, Arizona, and the traditional Islamic houses that exploit natural ventilation for cooling the space with typical wind-towers. Traditional buildings of similarly high energy efficient performance are the circular igloos which due to the absence of external openings minimize heat loss to the outside, or the semi-diged buildings located in Greek islands, which due to their high thermal inertia remain almost unaffected interiors from changes in external temperature. Similarly, housing in multi-floor dwellings may be seasonal, i.e. living on the ground floor in the summer months and on the upper floors during winter (Karatsiori, 2008).
Regarding the Greek traditional architecture, some of the basic features of traditional Greek homes are patios, courtyards and solar spaces, called “Glass-ROOM”, which are fundamental bioclimatic components. Additionally, the various types of windows and shading used as pergolas, awnings, shutters, are elements that together with other reported ones reflect the traditional wisdom which ultimately is timeless and continue even today used in modern bioclimatic architecture (Serghides, 2010).
The Energy Inspection of Buildings was also instituted in our country by the Regulation Energy Performance of Buildings (KENAK) and the Presidential Decree for Energy Inspectors, as well as by the creation of the Special Energy Inspectors Service. The specific regulatory framework established by the new regulation on energy, which provides clear instructions and guidelines for rational energy building design and allows for quick and inexpensive inspection of buildings.
‘Energy audit is the process of assessing the actual energy consumption, the factors affecting them and the improving methods for saving energy in buildings’. (1)
The whole process is designed so that the energy audit is an effective inspection system upgrading the country’s building stock and not a formal and bureaucratic process. For conducting energy audit of a building a plurality of elements and data related to the characteristics of building shell, the climatic conditions, the electromechanical facilities and other factors where used. However, a particularly important role on the results of energy inspection and conclusions generated from it, expressed by the meaning of the ‘reference building’.
4.2.2 Reference building
The reference building is determined to be the same as the studied building. Specifically, it is considered to have the same geometry, orientation, use and operating characteristics of the existing building. The Reference building meets minimum standards and has defined technical features both external structural elements and in electromechanical facilities related to HAVAC indoor, production HWU and lighting (2). The technical instructions (TEE) set with detail the technical characteristics of the reference building so as to building envelope as well as for the electromechanical installations.