Professor of Sustainable Architecture, Marialena Nikolopoulou was educated as an architectural engineer and specialised in environmental design. After a short period in consultancy, she returned to the University of Cambridge for her PhD.
Before joining Kent in 2011, where she founded the Centre for Architecture and Sustainable environment, she worked at the University of Bath, where she founded the EDEn Research Unit and the Centre for Renewable Energy Sources in Greece, where she developed and co-ordinated the EU-funded project, ‘RUROS’ on urban comfort.
Her research interests concentrate on environmental performance of buildings and urban spaces, thermal comfort, along with occupant perception and use of space.
Marialena has an international profile and is frequently invited as a speaker at conferences and workshops around the world. She has received awards from diverse bodies, including the 2001 prestigious Human Biometeorology Scientific Award from the International Society of Biometeorology and the PLEA 2000 and 2009 awards. Her research has been funded by the EU, EPSRC, AHRC, TSB, HLF, RIBA, UK Science Bridges, WIMEK from The Netherlands as well as local government.
- Panel Member for evaluation of R&D in the built environment in Estonia, Estonian Research Council (2017)
- Standing Review Board Member of Humanities and Social Sciences Panel of Research Grants Council, Hong Kong (from 2015)
- Steering Committee of CIBSE Environmental Design Guide A (from 2015)
- Panel Member of the 2014 Research Assessment Exercise (RAE 2014) for Hong Kong, University Grants Committee
- Panel Member for the Hellenic Quality Assurance and Accreditation Agency for Higher Education (HQA) in Greece for the Evaluation of Architectural Engineering, Democritus University (2013)
- Member of the EPSRC Peer Review College (from 2012)
- Member of the DCLG Behavioural Research Network (2011-2013)
- Peer reviews for EPSRC, MRC, EU Framework Programmes, research councils of Netherlands, Portugal, Greece, Cyprus, Welsh Government, Israel, Qatar and Hong-Kong.
- EPSRC “Urban albedo computation in high latitude locations: an experimental approach” with the universities of Brunel and Loughborough (2017-2020)
- WIMEK Visiting Research Fellow, Wageningen Institute for Environment and Climate Research (2017-18)
- AHRC Cultural Engagement Fund “Sensory Navigation in the Canterbury Journey” with Canterbury Cathedral (2016)
- Heritage Lottery Funds via Thanet District Council “Exemplar Climate Change Project, for the sustainable refurbishment and extensive monitoring of a heritage townhouse in Dalby Square, Margate” (2015-2018)
- Tianjin University Innovation Base, Ministry of Education of China “Low-carbon city and architecture” Innovation Base Introducing International Talents (2012-2017).
- EPSRC “Digital Economy: Communities and Culture Network+” with the universities of Leeds, Sussex and Aberdeen (2012-2016)
- E-iNet “Develop performance specifications for climate change adaptation strategies for the architectural brief and a detailed monitoring protocol for the monitoring and evaluation of the refurbished heritage townhouse in Margate” with Daedalus Environmental (2015)
- AHRC Creative Exchange Lab (via Lancaster University) “Paths of Desire” (2015)
- EPSRC “Mapping the lived experience of food bank clients and volunteers” Scoping study funded by the “Communities and Culture Network+” (2013-2014)
- AHRC Communities, Cultures, Environments and Sustainability pilot “Eco-cultural production in a Changing World” (2013)
- TSB "Building Performance Evaluation of the Jarman School of Arts" (2012-2014) with Hawkins/Brown architects and Arup M&E builders
- EPSRC "Digital Economy: Communities and Culture Network+" (2012-2015), with the Universities of Leeds, Sussex and Aberdeen
- EPSRC "Shades of Grey – Towards a Science of Interventions for Eliciting and Detecting Notable Behaviours" (2010-2013), with the Universities of Swansea, UCL, Bath, Essex, Leeds Metropolitan, UEL, Arts London, Nottingham and York
- EPSRC "Integration of active and passive indoor thermal environment control systems to minimise the carbon footprint of airport buildings" (2009-2012), with the Universities of Brunel, City, Loughborough and De Montford
- EPSRC "Coincident Probabilistic climate change weather data for a Sustainable built Environment" (2008-2011), with the Universities of Manchester, Sheffield, Bath, Herriot Watt and Northumbria
- GWR "Developing low energy contemporary buildings for hot arid regions" Great Western Research co-funded by the South-West Regional Development Agency and Hoare Lea (2008-2011), with the Universities of Bath and UWE
- EU URBAN-NET "The potential impact of climate change on heat stress in different building structures and cities across Europe" (2008-2009) with the Universities of Gothenburg and Freiburg
- SET2 partnership "Personal perception of air pollution in the urban environment" UK-US Collaboration programme (2008) with the University of California San Diego
- University of Bath "Monitoring comfort conditions in the Department of Architecture and Civil Engineering" (2008-2010)
- External advisor to the project funded by FAPESP the Research Support Foundation for the State of São Paulo, Brazil "Thermal comfort in public open spaces: a methodology for medium cities in São Paulo State" (2007-2009)
- British Academy Overseas Conference Grant (2007)
- University of Bath Studentship "Outdoor thermal comfort in the hot dry climate" (2006-2009)
- EURONETRES: "European Network on Education and Training in Renewable Energy Sources", UNESCO, Regional Bureau for Science in Europe (ROSTE). Working group "Solar Passive Systems for Sustainable Architecture" (2005-2007)
- EU FP5 Steering Committee of the GREENCLUSTER network – European Network for the Green in the Urban Environment (2002-2005)
- EU FP5 Project co-ordinator and overall PI: "RUROS: Rediscovering the Urban Realm and Open Spaces" (2001-2004), 12 teams across Europe
|Module Code||Module Title||Information|
|AR597||Dissertation (BA Architecture)||Tutor|
|AR829||Monitoring and Modelling of Environmental Performance||Tutor|
|AR830||Sustainable Design Project||Tutor|
|AR899||Dissertation (MSc Architecture and Sustainable Environment)||Tutor|
Also view these in the Kent Academic Repository
Pantavou, K. et al. (2018). Thermal sensation and climate: a comparison of UTCI and PET thresholds in different climates. International Journal of Biometeorololgy [Online] 62:1695-1708. Available at: https://doi.org/10.1007/s00484-018-1569-4.The influence of physiological acclimatization and psychological adaptation on thermal perception is well documented and has revealed the importance of thermal experience and expectation in the evaluation of environmental stimuli. Seasonal patterns of thermal perception have been studied, and calibrated thermal indices' scales have been proposed to obtainmeaningful interpretations of thermal sensation indices in different climate regions. The current work attempts to quantify the contribution of climate to the longterm thermal adaptation by examining the relationship between climate normal annual air temperature (1971–2000) and such climate-calibrated thermal indices' assessment scales. The thermal sensation ranges of two thermal indices, the Universal Thermal Climate Index (UTCI) and the Physiological Equivalent Temperature Index (PET), were calibrated for three warm temperate climate contexts (Cfa, Cfb, Csa), against the subjective evaluation of the thermal environment indicated by interviewees during field surveys conducted at seven European cities: Athens (GR), Thessaloniki (GR),Milan (IT), Fribourg (CH),Kassel (DE), Cambridge (UK), and Sheffield (UK), under the same research protocol. Then, calibrated scales for other climate contexts were added from the literature, and the relationship between the respective scales' thresholds and climate normal annual air temperature was examined. To maintain the maximum possible comparability, three methods were applied for the calibration, namely linear, ordinal, and probit regression. The results indicated that the calibrated UTCI and PET thresholds increase with the climate normal annual air temperature of the survey city. To investigate further climates, we also included in the analysis results of previous studies presenting only thresholds for neutral thermal sensation. The average increase of the respective thresholds in the case of neutral thermal sensation was about 0.6 °C for each 1 °C increase of the normal annual air temperature for both indices, statistically significant only for PET though
Adekunle, T. and Nikolopoulou, M. (2018). Post-occupancy evaluation on people's perception of comfort, adaptation and seasonal performance of sustainable housing: a case study of three prefabricated structural timber housing developments. Intelligent Buildings International [Online]. Available at: https://doi.org/10.1080/17508975.2018.1493677.This paper discusses the results of the post-occupancy evaluation conducted in three-prefabricated timber housing developments. The study investigated occupants' perception of comfort, adaptation to the thermal environment, and seasonal performance of the buildings. The buildings are constructed with engineered timber products (SIPs and CLT). The survey was conducted in the summer, but it also evaluated the performance of the buildings in winter. The results show 81% of the respondents feel 'warm' in summer. More than 50% of the respondents feel 'neutral' or 'slightly warm' in winter. Over 90% of the participants conﬁrmed the use of control with higher control satisfaction. Higher control satisfaction votes observed in one of the buildings are found to be strongly inﬂuenced by the occupancy period and ownership status. The respondents who are satisﬁed with control perceived a high level of control across the case study buildings. The importance of control for thermal comfort/satisfaction may be a contributing factor as control increases; a key suggestion for widening the adaptive actions of people in buildings. Overall, the results showed the occupants did not perceive extreme summertime overheating at the buildings, despite higher thermal sensation votes (summer) recorded during the survey. The study provides an insight into occupants' perception of comfort and adaptation in the buildings. The study identiﬁes the signiﬁcant impact of control on occupants' comfort and adaptation. The paper concludes that the buildings perform better in winter than summer.
Chatzipoulka, C. et al. (2018). Sky view factor as predictor of solar availability on building façades. Solar Energy [Online] 170:1026-1038. Available at: https://doi.org/10.1016/j.solener.2018.06.028.Solar availability on urban façades varies signiﬁcantly, aﬀected by obstructions by nearby buildings as well as orientation. A convenient way to evaluate their solar energy potential is deemed to facilitate the task of architects in increasing the use of photovoltaic systems and, thus solar energy generation in the urban environment. This study explores to what extent the sky view factor (SVF), a measure of the openness of a point to the sky, can be employed for evaluating solar irradiation of façades in complex urban scenes. For this purpose, extensive statistical analysis was performed testing the correlation of SVF with solar irradiances for 30 orientations, considering three European climates (i.e. Athens, London and Helsinki), and three periods (i.e. year, January and July). Special emphasis is put on global irradiance, which expresses the sum of three solar components, i.e. direct, diﬀuse and reﬂected. The study uses 24 urban forms - of 500 × 500 m area - in London for which SVF and solar irradiance simulations were performed for nine sky models (three locations by three periods). The results reveal a strong linear relationship (R2 > 0.8) between SVF and annual global irradiance in all orientations, at all three locations. In fact, as SVF was found to correlate well with both major solar components, direct and diﬀuse, it can be presumably used for predicting façades' annual solar irradiation at any location within the tested range of latitudes. With respect to monthly global irradiance, the relationship appears less consistent, aﬀected by the increased sensitivity of the relationship of SVF with monthly direct irradiance to façade orientation and location's latitude, associated with the variations of solar altitude.
Aljawabra, F. and Nikolopoulou, M. (2018). Thermal comfort in urban spaces: a cross-cultural study in the hot arid climate. International Journal of Biometeorology [Online]. Available at: https://doi.org/10.1007/s00484-018-1592-5.This cross-cultural research is an inaugural attempt to investigate the outdoor thermal comfort and the effect of cultural and social differences in hot arid climates. Case studies were carefully selected in two different parts of the world (Marrakech in North Africa and Phoenix, Arizona, in North America) to represent two different cultures in similar climatic context. Field surveys, carried out during winter and summer, included structured interviews with a standard questionnaire, observations and microclimatic monitoring. The results demonstrate a wide thermal comfort zone and prevalence of air-conditioning influencing thermal comfort requirements. The work also provides evidence of substantial cross-cultural differences in thermal comfort requirements between residents in Marrakech and Phoenix. It shows that adaptive measures, such as level of clothing, changing place, cold drinks consumption and thermal experience, varies between cultures and this influences the thermal evaluation of visitors in outdoor spaces in the hot arid climate. Evidence between the time spent in outdoor spaces and thermal expectations has been found. Moreover, environmental variables such as air temperature and solar radiation have a great impact on the use of the outdoor spaces in the hot arid climate and may determine the number of people in urban spaces. The study also identified significant differences in thermal comfort requirements between different socio-economic groups, highlighting the need for comfortable open spaces.
Chatzipoulka, C. and Nikolopoulou, M. (2018). Urban Geometry, SVF and Insolation of Open Spaces: the case of London and Paris. Building Research & Information [Online] 46:881-898. Available at: https://doi.org/10.1080/09613218.2018.1463015.The radiant environment in open spaces is very sensitive to the surrounding built form, which determines their openness to the sky and exposure to the sun. This paper presents the analysis of 132 urban forms in London and Paris, two cities at similar geographical latitude, but of different urban geometry, focusing on the relationship between urban geometry and insolation of open spaces at neighbourhood scale. The method consists of three stages: (1) the geometric analysis of the urban forms, (2) their solar access analysis and (3) the statistical exploration of the results. Special emphasis is on the sky view factor (SVF), which is employed as an integrated geometry variable and environmental performance indicator. The comparative analysis of the two cities underlines the significance of urban layout for modifying the outdoor radiant environment, and reveals temporal characteristics of the relation between urban geometry and insolation of urban forms, induced by the varying solar geometry. Indicatively, the average mean ground SVF (mSVF) was found to be primarily affected by the quantitative characteristics of the open space, and able to predict average daytime insolation on March 21 and June 21 (R2 > 0.8), in both cities.
Tseliou, A., Tsiros, I. and Nikolopoulou, M. (2017). Seasonal differences in thermal sensation in the outdoor urban environment of Mediterranean climates – The example of Athens, Greece. International Journal of Biometeorololgy [Online]. Available at: http://dx.doi.org/10.1007/s00484-016-1298-5.Outdoor urban areas are very important for cities and microclimate is a critical parameter in the design process, contributing to thermal comfort which is important for urban developments. The research presented in this paper is part of extensive field surveys conducted in Athens aimed at investigating people's thermal sensation in a Mediterranean city. Based on 2313 questionnaires and microclimatic data the current work focuses on the relative frequencies of people's evaluation of the thermal along with the sun and wind sensations between two seasons trying to identify the seasonal differences in thermal sensation. The impact of basic meteorological factors on thermal discomfort with respect to season are also examined, as well as the use of the outdoor environment. Results show that psychological adaptation is an important contributing factor influencing perception of the thermal environment between seasons. In addition, the thermal sensation votes during the cool months show that individuals are satisfied to a great extend with the thermal environment whereas the combination of high air temperature, strong solar radiation and weak wind lead to thermal discomfort during summertime. As far as the appropriate urban design in the Mediterranean climate is concerned, priority should be given to the warm months of the year.
Kotopouleas, A. and Nikolopoulou, M. (2017). Evaluation of comfort conditions in airport terminal buildings. Building and Environment [Online] 130:162-178. Available at: https://doi.org/10.1016/j.buildenv.2017.12.031.This paper presents findings from extensive field surveys in three airport terminal buildings in the UK, where the indoor environmental conditions were seasonally monitored and simultaneous structured interviews were conducted with 3087 terminal users. Moving beyond the recent work which brought to light the significantly differentiated requirements for thermal comfort between passengers and staff, this paper expands on the investigation of thermal and lighting comfort needs for the entire spectrum of terminal users under the scope of energy conservation. The results demonstrate the influence of the thermal environment on overall comfort and reveal consistent discrepancies, up to 2.1 °C, between preferred and experienced thermal conditions. Outdoor temperature dictated the clothing levels worn indoors, where the preferred thermal state was other than neutral. Terminal users demonstrated high levels of thermal tolerance and wide acceptability temperature ranges, averaging 6.1 °C in summer and 6.7 °C in winter, which allow for heating energy savings through the fine-tuning of indoor temperature set-points. Lighting comprises an additional field for energy savings through the maximisation of natural light. Bright rather than dim conditions were preferred and a preference for more natural light was evident even in cases where this was deemed to be sufficient, while the preference for more daylight was found to be time-dependent suggesting a link with the human circadian rhythm. The findings from this study can inform strategies aimed at reducing energy use in airport terminals without compromising comfort conditions as well as the design and refurbishment of new and existing terminals respectively.
Adekunle, T. and Nikolopoulou, M. (2016). Thermal comfort summertime temperatures and overheating in prefabricated timber housing. Building and Environment [Online] 103:21-35. Available at: http://dx.doi.org/10.1016/j.buildenv.2016.04.001.
Kotopouleas, A. and Nikolopoulou, M. (2016). Thermal comfort conditions in airport terminals: Indoor or transition spaces? Building and Environment 99:184-199.This paper reports on the investigation of the thermal comfort conditions in three airport terminals in the UK. In the course of seasonal field surveys, the indoor environmental conditions were monitored in different terminal areas and questionnaire-guided interviews were conducted with 3087 terminal users. The paper focuses on the thermal perception, preference and comfort requirements of passengers and terminal staff. The two groups presented different satisfaction levels with the indoor environment and significant differences in their thermal requirements, while both preferring a thermal environment different to the one experienced. The thermal conflict emerges throughout the terminal spaces. The neutral and preferred temperatures for passengers were lower than for employees and considerably lower than the mean indoor temperature. Passengers demonstrated higher tolerance of the thermal conditions and consistently a wider range of comfort temperatures, whereas the limited adaptive capacity for staff allowed for a narrower comfort zone.
Hirashima, S., de Assis, E. and Nikolopoulou, M. (2016). Daytime thermal comfort in urban spaces: A field study in Brazil. Building and Environment [Online] 107:245-253. Available at: http://dx.doi.org/10.1016/j.buildenv.2016.08.006.
Christina, C., Raphaël, C. and Marialena, N. (2016). Urban geometry and solar availability on façades and ground of real urban forms: using London as a case study. Solar Energy [Online] 138:53-66. Available at: http://dx.doi.org/10.1016/j.solener.2016.09.005.Availability of solar radiation in the urban environment is determined to a great extent by urban geometry, namely how densely built-up an area is and how the given built volume is distributed spatially within the site. This paper explores relationships between urban geometry and solar availability on building façades and at the pedestrian level, with implications for buildings' passive potential and outdoor thermal comfort, respectively. The study was based on the morphological and solar analysis of 24 urban forms of London, covering a wide range of built density values found across the city. Two aspects of solar availability were investigated at the neighbourhood scale, through statistical analysis: i) the relationships between urban geometry variables and solar availability indicators in different time periods, and ii) the seasonal solar performance of urban forms' façades and ground. Apart from the strong, negative effect of density, the analysis revealed that solar availability on ground and façades is significantly affected by urban layout. Mean outdoor distance, site coverage, directionality and complexity were the most influential for the solar performance of open spaces; whilst building façades were mostly affected by complexity, standard deviation of building height and directionality. However, direct solar irradiance on ground and façades was found to be influenced by different variables in January and July, which is attributed to the different solar altitude angles. Related to that, urban forms have been identified that present higher irradiance values in January and lower in June when compared to others. Considering temperate climates, these examples highlight the potential for enhancing the seasonal solar performance of existing and future urban developments. Finally, the seasonal effect on solar availability appears to be much more pronounced for ground with its mean direct irradiance value increasing on average by a factor 15, from January to July, while for façades the increase is only by a factor 2.6.
Kotopouleas, A. and Nikolopoulou, M. (2016). Thermal comfort conditions in airport terminals: Indoor or transition spaces? Building and Environment [Online] 99:184-199. Available at: http://dx.doi.org/10.1016/j.buildenv.2016.01.021.This paper reports on the investigation of the thermal comfort conditions in three airport terminals in the UK. In the course of seasonal field surveys, the indoor environmental conditions were monitored in different terminal areas and questionnaire-guided interviews were conducted with 3087 terminal users. The paper focuses on the thermal perception, preference and comfort requirements of passengers and terminal staff. The two groups presented different satisfaction levels with the indoor environment and significant differences in their thermal requirements, while both preferring a thermal environment different to the one experienced. The thermal conflict emerges throughout the terminal spaces. The neutral and preferred temperatures for passengers were lower than for employees and considerably lower than the mean indoor temperature. Passengers demonstrated higher tolerance of the thermal conditions and consistently a wider range of comfort
Queiroz da Silveira Hirashimaa, S., Sad de Assisb, E. and Nikolopoulou, M. (2016). Dataset on daytime outdoor thermal comfort for Belo Horizonte, Brazil. Data in Brief [Online] 9:530-535. Available at: http://dx.doi.org/10.1016/j.dib.2016.09.019.This dataset describe microclimatic parameters of two urban open public spaces in the city of Belo Horizonte, Brazil; physiological equivalent temperature (PET) index values and the related subjective responses of interviewees regarding thermal sensation perception and preference and thermal comfort evaluation. Individuals and behavioral' characteristics of respondents were also presented. Data were collected at daytime, in summer and winter, 2013. Statistical treatment of this data was firstly presented in a PhD Thesis  providing relevant information on thermal conditions in these locations and on thermal comfort assessment. Up to now, this data was also explored in the article "Daytime Thermal Comfort in Urban Spaces: A Field Study in Brazil" . These references are recommended for further interpretation and discussion.
Nikolopoulou, M., Martin, K. and Dalton, B. (2015). Shaping pedestrian movement through playful interventions in security planning: what do field surveys suggest? Journal of Urban Design [Online]:1-21. Available at: http://dx.doi.org/10.1080/13574809.2015.1106913.The control and shaping of pedestrian movement recurs as an aspect of security planning for crowded spaces. Using the concepts of triangulation, performance and flow, this paper presents a series of experiments designed to shape pedestrian movement patterns in public spaces in different spatial and operation contexts, by eliciting noticeable behaviours and disrupting routine use of space. The hypothesis investigated is that playful, non-obstructive interventions foster a positive social experience yet can be used to shape pedestrian movement. The interventions examined were around the themes of floor marking and mirrors. Analysis demonstrated that the interventions were able to create zones of attraction and exclusion, engage people's curiosity and elicit playful actions. Habituation, goal-directed behaviour and the influence of increased cognitive load at personal level were all important factors responsible for reducing the level of engagement with an intervention. The results suggest that increased understanding between environmental and interpersonal stimuli and behavioural responses can provide guidance in using socially acceptable design interventions to influence use of space in different operational contexts, contributing to sustainable security.
Nikolopoulou, M. (2011). Urban Open Spaces and Adaptation to Climate Change. in: Richter, M. and Weiland, U. eds. Applied Urban Ecology: A Global Framework. Blackwell. Available at: http://dx.doi.org/10.1002/9781444345025.ch9.
Adekunle, T. and Nikolopoulou, M. (2016). Evaluation of Prefabricated Structural Timber Housing. LAP Lambert Academic Publishing. Available at: https://www.morebooks.de/store/de/book/evaluation-of-prefabricated-structural-timber-housing/isbn/978-3-659-97787-9."Benefits of wood based designs include: exceptional insulator and energy saver; quick to build; environmentally friendly; aesthetically acrobatic; mechanical and working properties; safe, light, sturdy and durable; water resistant; healthy and natural; acoustically sound; and no rust. In conclusion, wood is good". David Daniel in Freshome's Very Best. The book evaluates prefabricated structural timber housing. It presents case study buildings built with structural timber materials. From the design perspective, the book describes the buildings and presents its findings on space standards used for construction. From a building construction and structure point of view, the book presents materials and construction methods used for the buildings. It explains the structural integrity of the buildings. Since the buildings are built with timber, the book presents environmental sustainability of each building to understand carbon footprint of the buildings. Finally, it provides similarities and differences between the buildings to understand lessons and importance of sustainable timber buildings that have capacity to capture carbon over their lifetime with low or no environmental impacts.
Conference or workshop item
Nikolopoulou, M., Kotopouleas, A. and Lykoudis, S. (2018). From indoors to outdoors and in-transition; thermal comfort across different operation contexts. in: 10th Windsor Conference: Rethinking Comfort.. Available at: http://windsorconference.com/.This paper focuses on the investigation of thermal comfort conditions in three very different operational contexts using meta-analysis of different studies within a similar climatic context in the UK. This includes extensive surveys indoors from offices, outdoors from urban areas, as well as indoors from airport terminals. Recent research in airport terminal buildings has highlighted that there are very different user groups, with diverse requirements for thermal comfort in such facilities. The paper investigates the hypothesis that staff working in the different areas have needs more similar to those of staff working in offices, while passengers use the building as a transition area with very different requirements and hence closer to the outdoor environment. Analysing and comparing the thermal comfort conditions from the different contexts, it explores the role of adaptation for thermal comfort attainment and satisfaction with the environment and the similarities of very different operational contexts in terms of their thermal comfort characteristics. Finally, the paper highlighted techniques for the potential transformation of thermal comfort scales, which can enable comparison between different types of surveys and inform the wider thermal comfort debate.
Chatzipoulka, C., Nikolopoulou, M. and Watkins, R. (2015). The impact of urban geometry on the radiant environment in outdoor spaces. in: ICUC9 9th International Conference on Urban Climate.. Available at: http://www.meteo.fr/icuc9/.Urban geometry, namely the quantitative relationship of building volumes and open spaces (i.e. built density) and their spatial configuration (i.e. urban layout), is a major modifier of urban microclimate. This paper presents the results of an ongoing research which explores the impact of urban geometry on the radiant environment in outdoor spaces, with direct implications for urban microclimate and outdoor thermal comfort. In particular, the research investigates the relationship between a set of urban geometric indicators (such as Built Density, Site Coverage, Mean building Height and Frontal Area Density) and Mean Radiant Temperature (Tmrt) at the pedestrian level, in different areas of London. Three representative areas of London were selected to be studied; in central, west and north London which are of high, medium and low built density, respectively. Each area was divided into squares of 500m x 500m size, with a total of 84 urban squares included in the study. The methodology comprises three stages: (i) A set of simple geometric indicators have been computed for all urban squares using special algorithms written and executed in Matlab software. (ii) Radiation simulations have been performed for 10 days of a typical year in London, with the use of SOLWEIG software. SOLWEIG simulates hourly, 3-D radiation fluxes, incoming to / outgoing from the ground, spatial variations of Tmrt, Ground View Factor (GVF) as well as Sky View Factor (SVF). Sunny and cloudy days have been considered, evenly distributed in the year in order for the effect of solar angles to be examined. (iii) Statistical tests have been conducted for investigating the correlation between urban geometry, as expressed by the geometric variables, and hourly, average values of Mean Radiant Temperature in the outdoor spaces of the urban squares. The simulation results show that at night-time and in fully overcast conditions, the outdoor spaces of central London's urban squares are warmer than those of west and north London, due to greater longwave radiation emitted and reflected by building volumes. In contrast, on sunny days, average daytime Tmrt values have been found to be higher in North London's urban squares due to the larger insolation of their outdoor spaces. Additionally, the statistical analysis has shown that in the absence of direct solar radiation, the correlation between the geometrical variables and average values of Tmrt is very high with an almost perfect linear relationship between the geometrical variables and average SVF values (r2= 0.980). In the presence of direct solar radiation, the strength of the correlation varies with the sun altitude angle; the higher the sun altitude angle, the higher the correlation. In particular, a threshold altitude angle of 20 degrees has been identified, above which the correlation of average Tmrt values with urban geometry approximates that of night-time / cloudy hours. Finally, further statistical tests showed that site coverage (built area over site area) and frontal area density (façades' total area over site area) are the strongest indicators among those considered in the analysis.
Watkins, R. et al. (2015). The Performance of Natural Ventilation In A Dance Studio – Lessons From Tracer Gas Measurements And Control Integration. in: 31st International PLEA Conference, Passive Low Energy Architecture.The naturally ventilated, three storey School of Arts Jarman Building provides two dance studios, an exhibition gallery, teaching rooms, video editing suites and offices. The main dance studio is double-height, has underfloor heating and accommodates sixty people. Fresh air enters from low level perimeter louvres and exits at high level through a stack that rises through the third storey to a stack terminal with motorized louvres. Tracer gas (CO2) measurements were used to measure the ventilation rate in conjunction with hot-wire anemometry in the stack tower. The results showed that when all air inlet and exit louvres were set to closed, the residual air flow up the stack was 0.33m3/s representing a potential heat loss of 9kW in winter at 0°C outside. When the louvres were all open, the air flow increased to between 0.49 and 0.62m3/s, a level consistent with the studio's design occupancy. It was found that the studio's 4m high perimeter curtains represent a barrier to fresh air entering the main room space and cause the incoming air to migrate upwards towards the stack exit and effectively bypass the central part of the studio. Tracer gas decay rates showed that the main space experienced an air exchange rate 50% less than that for the overall studio. An investigation of the controls also revealed that the underfloor heating system operated independently of the control of the stack ventilation system, leading to simultaneous heating and venting. The research shows the vital importance of prescribing contractually that key controls are integrated, that fresh air dampers are well-sealed when closed, and the importance of designing a fresh air supply that matches the way a space is used.
Kotopouleas, A. and Nikolopoulou, M. (2014). Understanding Thermal Comfort Conditions in Airport Terminal Buildings. in: NCEUB. Available at: http://windsorconference.com/_archive/Proceedings_Windsor_Conference_2014.pdf.This paper presents the results from the thermal comfort studies at three airport terminal buildings in the UK where seasonal on-site surveys were conducted. The investigation involved extensive monitoring of the indoor environmental conditions along with 3,087 questionnaire-guided interviews with terminal users. The paper quantifies the thermal requirements of the terminal population and focuses on the thermal perception of passengers and staff in different terminal spaces. The findings demonstrate the preference for a different thermal environment than the one experienced and that thermal neutrality is found to lie at lower temperatures than those experienced, suggesting an overheating issue, predominantly in winter. Passengers and staff present different satisfaction levels with the indoor environment while their thermal sensation is greatly affected from the characteristics and function of the terminal spaces.