Papers by Athina G Gaglia
Renewable Energy, 2017
The standard efficiency of photovoltaics (PV) often deviates from the one achieved under real out... more The standard efficiency of photovoltaics (PV) often deviates from the one achieved under real outdoor conditions. This paper presents relevant data collected using a small multi-crystalline photovoltaic array at an outdoor experimental facility located north of Athens. Measurements during summer and winter periods were used to quantify the PV performance and operating characteristics. Several correlations are provided in order to facilitate the estimation of the actual PV performance with readily available local parameters (e.g. ambient air temperature, wind speed). The PV efficiency was found to be about 18% lower than that under laboratory standard test conditions, under similar operating conditions. The mean annual PV efficiency was 8.7%.
Energy and Buildings, 2003
This paper presents an overview of the results from a recently completed study on the assessment ... more This paper presents an overview of the results from a recently completed study on the assessment of the characteristics, current energy consumption and the potential for energy conservation in 29 Hellenic airports. The average annual total energy consumption at the airport terminals is 234 kWh/m 2 . A more detailed investigation for three representative airports, at different climatic zones, was also performed. Data was collected through energy audits of the three terminal buildings, thermal infrared (IR) inspections of the building envelopes and HVAC installations, an assessment of indoor environmental quality (IEQ) through long term monitoring and spot measurements of indoor thermal and visual conditions, as well as personnel and passenger questionnaires. The collected information was used to perform a detailed analysis using thermal simulations for assessing specific measures to reduce energy use without compromising comfort, and to identify possible actions for improving IEQ. For the three airports, potential energy savings range at 15-35%, while improving and maintaining indoor environmental quality.
Energy, 1994
School buildings (238) in Hellas were audited for construction, heating, cooling, lighting, and m... more School buildings (238) in Hellas were audited for construction, heating, cooling, lighting, and mechanical and electrical systems. The annual average total energy consumption is 93 kWh/m', of which approximately 72% is consumed for space heating.
Energy Conversion and Management, Apr 15, 1994
Energy performance data for 30 health care buildings have been collected during an extensive ener... more Energy performance data for 30 health care buildings have been collected during an extensive energy audit of buildings in Hellas, within the frame of a National Energy Programme sponsored by the CEC VALOREN Programme for energy conservation in buildings. This short monitoring campaign was performed with on-site visits of a trained panel of engineers to each building, in order to register all information relevant to the buildings' construction, heating, cooling, lighting, systems and all other mechanical and electrical systems. The technical results of these audits, the role of the cooling and heating systems on the energy consumed in health care buildings, are discussed. The annual average total energy consumption in hospitals is 407 kWh/m2 and in clinics is 275 kWh/m2, the majority of which is consumed for space heating (73.4% in hospitals and 65.3% in clinics).
Several scenarios for possible interventions to the outer envelope of the buildings and to the heating, cooling and lighting systems, are proposed and evaluated, in order to assess the effectiveness of various energy conservation techniques. Based on the results from several simulations, it is concluded that it is possible to reach an overall 20% energy conservation. The energy consumption for heating can be reduced by 15% in hospitals and 11% in clinics by using more efficient heat production and distribution systems. Proper insulation of the buildings can conserve 173 kWh/m2 in hospitals and 103 kWh/m2 in clinics. Cooling can be reduced by 68% (in hospitals) and 56% (in clinics) by using night ventilation and by 80 and 97%, respectively, by using ceiling fans. Natural cooling techniques, under certain conditions, can also provide an important reduction of the cooling load. The use of high efficacy lamps can reduce the electric energy consumed for lighting by up to 50%. This information provides a representative picture of the existing conditions on energy consumption in health care buildings and can be used as guidelines for future energy efficient building construction.
The existing building stock in European countries accounts for over 40% of final energy consumpti... more The existing building stock in European countries accounts for over 40% of final energy consumption in the European Union (EU) member states, of which residential use represents 63% of total energy consumption in the buildings sector. Consequently, an increase of building energy performance can constitute an important instrument in the efforts to alleviate the EU energy import dependency (currently at about 48%) and comply with the Kyoto Protocol to reduce carbon dioxide emissions. This is also in accordance to the European Directive (EPBD 2002/91/EC) on the energy performance of buildings, which is currently under consideration in all EU member states. This paper presents an overview of the EU residential building stock and focuses on the Hellenic buildings. It elaborates the methodology used to determine the priorities for energy conservation measures (ECMs) in Hellenic residential buildings to reduce the environmental impact from CO2 emissions, through the implementation of a realistic and effective national action plan. A major obstacle that had to overcome was the need to make suitable assumptions for missing detailed primary data. Accordingly, a qualitative and quantitative assessment of scattered national data resulted to a realistic assessment of the existing residential building stock and energy consumption. This is the first time that this kind of aggregate data is presented on a national level. Different energy conservation scenarios and their impact on the reduction of CO2 emissions were evaluated. Accordingly, the most effective ECMs are the insulation of external walls (33–60% energy savings), weather proofing of openings (16–21%), the installation of double-glazed windows (14–20%), the regular maintenance of central heating boilers (10–12%), and the installation of solar collectors for sanitary hot water production (50–80%).
Hospital operating rooms (ORs) require efficient HVAC installations to secure the highly demandin... more Hospital operating rooms (ORs) require efficient HVAC installations to secure the highly demanding indoor environmental conditions for patients and medical personnel. This paper reviews published standards and guidelines on design, installation, commissioning, operation, and maintenance of HVAC installations in hospital ORs, indoor thermal conditions, and summarizes measured data from short monitoring of indoor thermal conditions along with audit results and main characteristics of 20 ORs in 10 major Hellenic hospitals. Measured indoor temperature ranged from 14 to 29°C, and relative humidity from 13 to 80%. The number of air changes per hour ranged from 3.2 to 58 ACH. The commonly encountered problems include insufficient indoor air exchange, poor control on indoor thermal conditions, bad space ergonomics that influence the ventilation system operation, poor technical installations maintenance and understaffed technical departments. However, there are still opportunities for energy conservation, without sacrificing comfort, and overall quality of patient care or services.
Proceedings of the Energy Sustainability Conference 2007, 2007
The existing buildings stock in European countries accounts for over 40% of final energy consumpt... more The existing buildings stock in European countries accounts for over 40% of final energy consumption in the European Union (EU) member states. Consequently, an increase of building energy performance can constitute an important instrument in the efforts to alleviate the EU energy import dependency and comply with the Kyoto Protocol to reduce carbon dioxide emissions. This is also in accordance to the European Directive on the Energy Performance of Buildings (EPBD), which is currently under implementation in all EU member states.
Solar Energy, 1994
The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original docum and are linked to publications on ResearchGate, letting you access and read them immediately.
Comprehensive information and detailed data for the non-residential (NR) building stock is rather... more Comprehensive information and detailed data for the non-residential (NR) building stock is rather limited, although it is the fastest growing energy demand sector. This paper elaborates the approach used to determine the potential energy conservation in the Hellenic NR building stock. A major obstacle that had to be overcome was the need to make suitable assumptions for missing detailed primary data. A qualitative and quantitative assessment of scattered national data resulted in a realistic assessment of the existing NR building stock and energy consumption. Different energy conservation scenarios and their impact on the reduction of CO2 emissions were evaluated. Accordingly, the most effective energy conservation measures are: addition of thermal insulation of exposed external walls, primarily in hotels and hospitals; installation of energy efficient lamps; installation of solar collectors for sanitary hot water production, primarily in hotels and health care; installation of building management systems in office/commercial and hotel buildings; replacement of old inefficient boilers; and regular maintenance of central heating boilers.
Energy Conversion and Management, 1994
Energy performance data for 30 health care buildings have been collected during an extensive ener... more Energy performance data for 30 health care buildings have been collected during an extensive energy audit of buildings in Hellas, within the frame of a National Energy Programme sponsored by the CEC VALOREN Programme for energy conservation in buildings. This short monitoring campaign was performed with on-site visits of a trained panel of engineers to each building, in order to register all information relevant to the buildings' construction, heating, cooling, lighting, systems and all other mechanical and electrical systems. The technical results of these audits, the role of the cooling and heating systems on the energy consumed in health care buildings, are discussed. The annual average total energy consumption in hospitals is 407 kWh/m 2 and in clinics is 275 kWh/m 2, the majority of which is consumed for space heating (73.4% in hospitals and 65.3% in clinics).
Indoor environmental quality (IEQ) in hospital operating rooms (ORs) constitutes a major challeng... more Indoor environmental quality (IEQ) in hospital operating rooms (ORs) constitutes a major challenge for the proper design and operation of an energy efficient hospital. A subjective assessment of the indoor environment along with a short monitoring campaign was performed during the audits of 18 ORs at nine major Hellenic hospitals. A total of 557 medical personnel participated in an occupational survey, providing data for a subjective assessment of IEQ in the audited ORs. The OR personnel reported work related health symptoms and an assessment of indoor conditions (thermal, visual and acoustical comfort, and air quality). Overall, personnel reported an average of 2.24 work-related symptoms each, and 67.2% of respondents reported at least one. Women suffer more health symptoms than men. Special dispositions, such as smoking and allergies, increase the number of reported symptoms for male and female personnel. Personnel that perceive satisfactory indoor comfort conditions (temperature, humidity, ventilation, light, and noise) average 1.18 symptoms per person, while for satisfactory indoor air quality the average complaints are 0.99. The perception of satisfactory IEQ (satisfactory comfort conditions and air quality) reduces the average number of health complaints to 0.64 symptoms per person and improves working conditions, even in a demanding OR environment.
Energy and Buildings, 1996
... result from the use of practical retrofitting techniques, materials and new energy efficient ... more ... result from the use of practical retrofitting techniques, materials and new energy efficient systems are ... The data were collected during an extensive energy audit of buildings that was ... In: M. Santamouris, Editor, Natural Cooling Techniques in Greece, The Centre for Renewable ...
Building and Environment, 2007
The existing building stock in European countries accounts for over 40% of final energy consumpti... more The existing building stock in European countries accounts for over 40% of final energy consumption in the European Union (EU) member states, of which residential use represents 63% of total energy consumption in the buildings sector. Consequently, an increase of building energy performance can constitute an important instrument in the efforts to alleviate the EU energy import dependency (currently at about 48%) and comply with the Kyoto Protocol to reduce carbon dioxide emissions. This is also in accordance to the European Directive (EPBD 2002/91/EC) on the energy performance of buildings, which is currently under consideration in all EU member states. This paper presents an overview of the EU residential building stock and focuses on the Hellenic buildings. It elaborates the methodology used to determine the priorities for energy conservation measures (ECMs) in Hellenic residential buildings to reduce the environmental impact from CO 2 emissions, through the implementation of a realistic and effective national action plan. A major obstacle that had to overcome was the need to make suitable assumptions for missing detailed primary data. Accordingly, a qualitative and quantitative assessment of scattered national data resulted to a realistic assessment of the existing residential building stock and energy consumption. This is the first time that this kind of aggregate data is presented on a national level. Different energy conservation scenarios and their impact on the reduction of CO 2 emissions were evaluated. Accordingly, the most effective ECMs are the insulation of external walls (33-60% energy savings), weather proofing of openings (16-21%), the installation of double-glazed windows (14-20%), the regular maintenance of central heating boilers (10-12%), and the installation of solar collectors for sanitary hot water production (50-80%). r
Indoor air quality in hospital operating rooms (ORs) is of great concern for patients and medical... more Indoor air quality in hospital operating rooms (ORs) is of great concern for patients and medical personnel, thus mandating the use of efficient HVAC systems and active gas scavenging systems in ORs. A wide range of relevant medical and engineering literature is summarized in this paper, highlighting relevant challenges, problems and solutions, along with recommended good practices. Indoor conditions in Hellenic ORs were monitored and data were used to assess the exposure of medical personnel to anaesthetic gases and other indoor chemical compounds. Accordingly, even when mechanical ventilation and scavenging systems were employed in some of the audited ORs, medical personnel are still exposed to poor indoor air quality. The average concentration of anaesthetic gases (isoflurane, sevoflurane) was 2362 mg/m3, exceeding the exposure limit in 18% of the audited ORs. The average concentration of disinfecting agents was 288 mg/m3 for formaldehyde and 207 mg/m3 for glutaraldehyde. Additional compounds were identified in the OR indoor air that represent 54% of the total volatile organic concentration.
Energy and Buildings, Aug 15, 2010
The process of building labeling and certification in accordance to the provisions of the Europea... more The process of building labeling and certification in accordance to the provisions of the European Directive on the Energy Performance of Buildings (EPBD) constitutes a unique opportunity for collecting information on the characteristics of the building stock and its energy performance on a national and European level. Thus, there is a need to handle data from a large stock of buildings and to be able to analyse information and extract practical trends and benchmarks. Stakeholders and technical managers who oversee a number of buildings experience similar needs in order to collect, organize and monitor the energy performance of a large pool of buildings. To facilitate these efforts, a common evaluation database and
complimentary software for its exploitation have been developed in the frame of a European project.
This paper presents an overview of the database and its available tools, and the main results from a case study on Hellenic buildings that reveals relevant characteristics. The Hellenic database included a sample of 250 buildings from different regions in Greece, with a breakdown that is representative of the national building stock. The main results focus on the buildings’ energy performance, thermal envelope characteristics and the exploitation of solar thermal energy.
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Papers by Athina G Gaglia
Several scenarios for possible interventions to the outer envelope of the buildings and to the heating, cooling and lighting systems, are proposed and evaluated, in order to assess the effectiveness of various energy conservation techniques. Based on the results from several simulations, it is concluded that it is possible to reach an overall 20% energy conservation. The energy consumption for heating can be reduced by 15% in hospitals and 11% in clinics by using more efficient heat production and distribution systems. Proper insulation of the buildings can conserve 173 kWh/m2 in hospitals and 103 kWh/m2 in clinics. Cooling can be reduced by 68% (in hospitals) and 56% (in clinics) by using night ventilation and by 80 and 97%, respectively, by using ceiling fans. Natural cooling techniques, under certain conditions, can also provide an important reduction of the cooling load. The use of high efficacy lamps can reduce the electric energy consumed for lighting by up to 50%. This information provides a representative picture of the existing conditions on energy consumption in health care buildings and can be used as guidelines for future energy efficient building construction.
complimentary software for its exploitation have been developed in the frame of a European project.
This paper presents an overview of the database and its available tools, and the main results from a case study on Hellenic buildings that reveals relevant characteristics. The Hellenic database included a sample of 250 buildings from different regions in Greece, with a breakdown that is representative of the national building stock. The main results focus on the buildings’ energy performance, thermal envelope characteristics and the exploitation of solar thermal energy.
Several scenarios for possible interventions to the outer envelope of the buildings and to the heating, cooling and lighting systems, are proposed and evaluated, in order to assess the effectiveness of various energy conservation techniques. Based on the results from several simulations, it is concluded that it is possible to reach an overall 20% energy conservation. The energy consumption for heating can be reduced by 15% in hospitals and 11% in clinics by using more efficient heat production and distribution systems. Proper insulation of the buildings can conserve 173 kWh/m2 in hospitals and 103 kWh/m2 in clinics. Cooling can be reduced by 68% (in hospitals) and 56% (in clinics) by using night ventilation and by 80 and 97%, respectively, by using ceiling fans. Natural cooling techniques, under certain conditions, can also provide an important reduction of the cooling load. The use of high efficacy lamps can reduce the electric energy consumed for lighting by up to 50%. This information provides a representative picture of the existing conditions on energy consumption in health care buildings and can be used as guidelines for future energy efficient building construction.
complimentary software for its exploitation have been developed in the frame of a European project.
This paper presents an overview of the database and its available tools, and the main results from a case study on Hellenic buildings that reveals relevant characteristics. The Hellenic database included a sample of 250 buildings from different regions in Greece, with a breakdown that is representative of the national building stock. The main results focus on the buildings’ energy performance, thermal envelope characteristics and the exploitation of solar thermal energy.