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• Climate change and urban setting impact energy use of buildings. • Energy use is higher due to overlapping effect of climate change and microclimate. • A method is proposed to account for future and urban environment in thermal simulation. • The results can assist in sizing passive ventilation systems. Urban settings and climate change both impact on energy use and thermal comfort inside buildings. This paper first presents a study of changes in energy demand in residential buildings considering the overlapping effect of climate change and urban heat island intensity in two European locations; Cadiz (Spain) and London (United Kingdom), representing temperate and hot European climates and moderate and dense urban settings. Future-urban weather files were generated and simulations were run considering energy demand and indoor thermal comfort. In hot climate regions such as the one of Cadiz, future climate will increase the cooling demand and the additional impact of the UHI leads to a further increase of up to +28% of total energy demand compared to the current climate without considering urban effects. Future-urban weather conditions will be detrimental also for buildings in London, where the annual energy demand is predicted to increase by up to the 16% if future climate and urban effects are included. This is due to a higher increase in cooling demand compared to the reduction for the heating need. The paper also presents a method to take into account microclimatic conditions in naturally ventilated buildings, especially the effect of wind variations around the building which impacts natural ventilation rates. Air and surface temperature and wind speeds were studied using ENVImet and the resulting microclimatic conditions were used as inputs to the EnergyPlus Airflow Network model for the calculation of the building ventilation rates. It was found that ventilation rates are reduced (in comparison to meteorological weather files) and this reduction impacts negatively on internal operative temperatures. A thermal comfort analysis was carried out indicating that the selection of a suitable weather file and microclimatic conditions is essential for more accurate predictions of internal thermal comfort and will assist in the sizing of passive and active systems to avoid overheating. [ABSTRACT FROM AUTHOR]

The urban heat island (UHI) phenomenon has become a concern in many major cities worldwide, as high summer temperatures and poor wind flow can have negative impacts on city dwellers, particularly increasing energy demand for artificial cooling. This paper showcases how an Integrated Multi-scale Environmental Urban Model (IMEUM) can be employed to support planners, architects and engineers to assess the combined impacts of the UHI phenomenon and rising global temperatures due to climate change. IMEUM concept derives from downscaling environmental models from global scale (25 km) to mesoscale (1 km) and city scale (100 m). Hence, this paper showcases a computationally efficient method which couples multi-scale atmospheric models with statistical model to estimate weather parameters. Developed under Singapore context, IMEUM can be utilized to incorporate appropriate UHI mitigation measures upfront in design process, consecutively bridging the gap between global and building scale. This paper also includes calibration of the IMEUM output using observations from ground sensors. Furthermore, by using case study of a hypothetical office building, this paper showcases how the IMEUM output can be fully converted into a localized weather data file for cooling load simulation. IMEUM is currently being developed further into integrated quantitative urban environment simulation tool (QUEST), which can be used to test the immediate microclimatic impact of development plans and assess their long term impacts under future climate change scenarios. [ABSTRACT FROM AUTHOR]

Urban climate change phenomena, exacerbated by increasingly frequent heat waves, represent an urgent environmental research issue to be further investigated and counteracted through multidisciplinary approaches covering both engineering and socio-environmental sciences. After acknowledging that Urban Heat Island hugely affects building thermal-energy behavior, recent contributions deal with its effect on vulnerable population groups in terms of their exposure risk to health diseases even worsened by energy poverty. In this view, the paper investigates the role played by occupants’ education and their knowledge of environmental risks and climate change-related events, by exploring the opportunity to improve their information level as trigger for improving their climate change behavioral resilience and reducing their health risk in the built environment during extreme events. To this aim, a novel widespread questionnaire was elaborated and submitted to more than 300 individuals with varying their educational background and personal characteristics, seasonal period, submission mode, temporal closeness to heat wave emergency. Key findings showed that participants’ educational background represents a clear way to drive environmentally aware behaviors minimizing the consequent health risk imputable to urban overheating and other environmental hazards such as heat waves. In fact, a higher level of awareness and consciousness may lead to a better adaptation capability to such climate change related hazards since they tend to implement conscious and resilient behavioral attitudes to minimize their indoor thermal stress at home (0.8 versus 1.4 points awareness level about mitigation strategies). Therefore, this paper demonstrated that informative campaigns may represent an effective strategy for making building occupants more resilient to climate change toward dedicated environmental management solutions and policies taking advantage of educational vehicles. [ABSTRACT FROM AUTHOR]

The paper aims to achieve the modelling of climate change effects on heating and cooling in the building sector, through the use of the available Intergovernmental Panel on Climate Change forecasted data. Data from several different climate models will be fused with regards to mean air temperature, wind speed and horizontal solar radiation. Several climatic models data were analysed ranging from January 2006 to December 2100. Rather than considering each model in isolation, we propose a data fusion approach for providing a robust combined model for morphing an existing weather data file. The final aim is simulating future energy use for heating and cooling of a reference building as a consequence of the expected climate changes. We compare results, in terms of robustness to overfitting, for two different fusion methodologies, based on the comparison between errors on punctual historical data or prediction models that can be obtained by each climate simulator and by the actual ERA-INTERIM data set. Finally, we map the new aggregated data into a prediction trace of heating and cooling energy requirements. The expected energy demand is in the range of the one provided by single climate models, with a variability that reaches up to the 10% of the overall energy requirements. The approach proposed is an advancement as it allows to achieve better fits with existing re-analysis data if compared to specific global circulation models output data. Thus a more reliable estimation of energy use for heating and cooling can be achieved. [ABSTRACT FROM AUTHOR]

The paper provides an overview of a part of research related to the analysis of information technologies and measures for improving the energy efficiency in urban planning that can contribute to mitigating the impact of climate change. The first part of the paper deals with problems supported by the numerous data on negative effects of climate change on the cities, such as urban heat islands, energy and ecological crisis. The second part of the paper proposes solutions that rely on information technologies which facilitate process of urban planning. Two projects related to the implementation of measures for improving the energy efficiency in urban planning were conducted within this research. The first one is considering the design of a spa centre in an undeveloped mountain landscape and the second one is dealing with reconstruction of a residential block in urban built environment. In the first case study, the proposed solutions rely on the information technologies, while in the second case study they rely on the implementation of measures for improving the energy efficiency in urban planning. The results show that the application of different measures in urban planning depends on the level of the built environment. [ABSTRACT FROM AUTHOR]

Urban heat island (UHI) and global warming effects will raise the ambient temperature of cities and increase building energy consumption. This paper discusses the residential cooling energy variations imposed by urban warming in the present and future. Data from a dynamically downscaled hourly meteorological model with a grid resolution of 5 km and for time slices 1979–2003, 2015–2039, and 2075–2099 were used for dynamic building energy simulation against a typical residential apartment in the central Taiwan region. The meteorological grids were classified as 4 city grids, 25 town grids, and 31 countryside grids based on their urban morphology attributes. The values from 20 countryside grids with lower average ambient temperatures during cooling seasons were selected as reference. The spatial and temporal distributions of the impact of indoor overheating risk and annual cooling energy consumption by UHI and global warming effects were quantified against the reference value. Furthermore, because the energy penalty can be used to rapidly estimate the urban warming impact on total cooling energy consumption of a given city, the linear correlation of the energy penalty and the magnitude of the UHI effect was also established and discussed. [ABSTRACT FROM AUTHOR]

Cities are dissipative structures. As such, cities generate heat, a phenomenon known as urban heat island (UHI). Even though the UHI is one of the most relevant effects of urbanization on urban climate, up-to-date methodologies to include it in the estimation of buildings’ energy consumption are still scarce. During the last 30 years, different methods and software have been developed to measure a thermal building's demand. Building performance simulation is commonly used to calculate heating and cooling demand. However, such techniques do not adequately include the urban heat island effect, which could have an extreme impact on a building's energy consumption. In fact, building operation is doubly connected with the urban environment: on the one hand, buildings generate heat that warms up the environment, and on the other hand, the urban environment alters building performance by the influence of UHI. In this paper, a methodology to incorporate the UHI effect in building performance simulation is proposed. Urban weather data were downscaled at the urban morphology building level to estimate the cooling demand of different types of residential buildings. The global energy penalty for the whole residential building stock was estimated in four South American Pacific coastal cities. The results indicate that when UHI is incorporated, an increase in energy demand between 15% and 200% can be expected. These results challenge the validity of current assessments performed in absence of the UHI effect. At the same time, these results open up the discussion for the inclusion of urban planning measures aiming at reducing the UHI effect on a building's energy demand. [ABSTRACT FROM AUTHOR]

Thermal performance are important parameter that represent the characteristic of cool pavement. The purpose of this paper is to present the findings on experimental result of thermal performance of the coating materials, which were developed from three types of waste tile aggregate, namely Full Body Porcelain (FBP), Monoporosa (MP) and Porcelain Glaze (PG). The samples were prepared based on the optimal design mix as proposed during optimization process based on surface temperature behavior of the samples. Experimental work was conducted in 24-h basis for continuously 14 days at actual tropical weather climate. The results showed that sample M1 with 100% of FBP provided the best result in terms of thermal performance, also the material was able to obtain highest surface temperature reduction up to 6.4 °C during peak period and solar reflectance of 0.49 at near infrared region. Statistical analysis shown that sample M4, 100% of PG tile aggregate, depicted a less desirable result due to its surface temperature reduction was not significant as compared with other investigated samples, which is only 4.32° during peak period. Overall result conclude that both material FBP and MP have a good potential to be used as cool pavement coating material based on its thermal and spectral performance. Thus, this study provides a useful information on the selection of tiles material that could be used as cool-pavement coatings, and contribute for a more potential measurement in mitigating urban heat island effects. [ABSTRACT FROM AUTHOR]

Despite the remarkable contribution of urbanisation to socio-economic development, it has complicated negative impacts on the environment. The growth of urbanisation has noticeable adverse impacts on urban microclimate and parameters generating the urban heat island (UHI) effect. These impacts, exacerbated by the gradual influences of global warming over time, make urban microclimate changes more complex. The future urban development and climate change adaptation plans in New Zealand (NZ) show almost no evidence of considering the status of future urban microclimate, UHI and outdoor thermal comfort. An initial literature review showed a relatively small number of papers and grey literature on urban microclimate in NZ. This motivated the authors to explore the status of studies on the urban microclimate and the following impacts on UHI and outdoor thermal comfort in NZ. The results showed a relatively small body of knowledge on urban microclimate studies in research articles published and governmental reports in the context of NZ. Likewise, the inconsistency of research parameters and methods studied and the lack of validation in the available studies, plus the neglection of future urban development and urban morphology, limit the clarity of the scientific understanding of changes to the urban microclimate in NZ. The results of this study address the missing links and provide new insight for future studies. This study suggests providing models that consider the continuous changes to the urban microclimate considering the uncertainty of climate change impacts on weather factors such as temperature and airflow. Assessment of the impact of current and future urban morphology on UHI is necessary to develop optimised urban design guidance. [ABSTRACT FROM AUTHOR]

• This paper determines the relationship between urban form and building energy use. • The surface-to-volume ratio and obstruction angle of buildings are important. • Consideration of the heating energy type and building use can yield reliable result. • The urban heat island effect exerts an impact on the electricity use in some months. • Correlation variation is caused by the building permit date. In the climate change era, urban geometry serves to ensure sustainability for urban planners since it notably affects building energy consumption. However, previous studies have mainly conducted experimental investigations under hypothetical conditions. Without empirical evidence, it is difficult to implement these findings under real conditions. This paper examined empirical data to determine the urban geometry effect on building energy consumption in a large, complicated urban area. Urban geometric parameters, including the surface-to-volume ratio, obstruction angle, and building orientation, were measured across Seoul, and their correlations with building energy use were analyzed. The results show that the surface-to-volume ratio and obstruction angle are important, despite the empirical data complexity. Additional data analysis indicates that the heating energy type and building use consideration yields more reliable correlation coefficient trends. The potential impacts of natural ventilation and the urban heat island (UHI) effect on building energy consumption were examined. The UHI effect, rather than shadows on buildings, predominantly impacts the building electricity use in August and September. The correlation variation caused by the building permit date was investigated. The results in this paper could help urban planners and designers develop blueprints to control urban geometry and establish relevant design guidelines. [ABSTRACT FROM AUTHOR]

Urban heat island and global warming increase ambient temperature and modify the energy budget of buildings. The magnitude of the modification has been evaluated in a large number of articles, under different climatic and building boundary conditions. This paper collects, analyzes and classifies existing knowledge regarding the energy impact of urban heating to buildings and calculates preliminary indicators and impact figures. Based on the analysis of the impact studies, it is found that in average the cooling load of typical urban buildings is by 13% higher compared to similar buildings in rural areas. Four specific energy impact indicators, the global energy penalty per m 2 , the global energy penalty per m 2 and degree of UHI, the global energy penalty per person and the global energy penalty per person and per degree of the UHI are defined and calculated. The variability of the heating and cooling loads of typical buildings is evaluated for the period 1970–2010. The average increase of the cooling demand is 23% while the corresponding average reduction of the heating is 19%. In total, the average energy consumption of typical buildings for heating and cooling purposes increased by 11% for the same period. [ABSTRACT FROM AUTHOR]

Abstract: The sensitivity of low energy and passive solar buildings to their climatic context creates a requirement for accurate local climate data. This situation takes on increasing importance in the context of modelling Passivhaus buildings where the absence of conventional oversized heating and cooling systems implies a greater reliance upon fabric and system optimisation. Conversely, future climatic changes may also pose serious implications for super insulated buildings with inadequate solar shading. Currently, many widely used building performance simulation (BPS) tools still rely on very limited sources of climate data. The following research examines the need for regional and, in some cases, micro-regional climatic data when designing ultra-low energy Passivhaus buildings in the UK. The paper proposes a new methodology for generating this data in PHPP format. The data generated is compared to alternative sources, and the implications discussed in the context of three case studies examining a certified Passivhaus dwelling in a mountainous region of Wales as well as two locations, in close proximity, within London. If correctly implemented the use of such data should provide a more robust basis for future cost and performance optimisation in low energy and passive building design. [Copyright &y& Elsevier]

Abstract: The urbanization and the deficiencies in proper development control have as consequence the environment''s degradation in urban centres and the change of microclimatic conditions. So, the urban microclimate of densely built areas is characterized by higher temperatures than the temperature of the suburbs and surrounding areas. Heating of the atmosphere and surfaces in urban areas compared to their surroundings is the phenomenon which is called urban heat island (UHI). The effect of building''s volume is considered as one of the main reasons for the urban heat island effect. Buildings, roads and paved surfaces, store the heat during the day and then release it slowly during the evening keeping the air temperature of the city hotter than surrounding areas. In other words, urban heat island cause thermal discomfort and it is responsible for the increase of energy demand in the buildings. This paper presents a study that aims at investigating the influence of urban morphology in microclimatic conditions. The investigation is carried out in Thessaloniki, Greece. The purpose of the research project is to measure how the temperature of building''s surfaces vary and interact during the day and according to the microclimatic parameters. There is a daily measurement of the examinated factors. Street orientation and configuration of the building blocks (height of buildings, width of road) are also important factors for the analysis of the measurements. [Copyright &y& Elsevier]

Abstract: Climatic change and heat island effect in combination with the non-proper design of buildings have increased substantially the cooling load of buildings. Night ventilation appears to be one of the more promising passive cooling techniques. Many important theoretical and experimental studies have been performed however the existing information is presented in a segmented way. The present paper analyses energy data from two hundred fourteen air conditioned residential buildings using night ventilation techniques. The specific absolute energy contribution of night ventilation has been calculated. The relation of the cooling demand of the buildings with the specific contribution of night ventilation has been investigated. It is found that the higher the cooling demand of the building, the higher the potential contribution of night ventilation under specific boundary conditions. The role of air flow rate is investigated as well. It is found that the global utilisability of the energy stored during the night increases as a function of the air flow rate and the tilt of the regression line between the energy contribution and the air flow rate increases significantly with the air flow rate applied, although the energy contribution per unit of air flow is decreasing. The whole analysis contributes towards a better understanding and evaluation of the expected energy contribution of night cooling techniques. [Copyright &y& Elsevier]

• A model to simulate interactions between a building and its outdoor conditions. • The model co-simulates EnergyPlus, OpenFOAM, and lumped thermal models. • The model provides proper estimates of outdoor conditions at the urban microscale. • Waste heat releases from the HVAC system can be simulated from the model. • Indirect and direct effects of green roofs can be considered by the model. This paper introduces a physically-based model to simulate interactions between a building and its outdoor conditions at the urban microscale. In the model, the building is simulated with EnergyPlus while its outdoor conditions are assessed from OpenFOAM. Furthermore, the model simulates the street pavement and surrounding buildings based on the lumped thermal theory. All components of the model are quasi-dynamically co-simulated. Through simulations of the model, waste heat releases from a cooling system can be observed with a higher resolution than this achieved by most urban microclimate models in the literature. Unlike several methods in the literature, the model evaluates a countermeasure to urban heat islands by considering direct and indirect effects simultaneously. To validate the model, measurements were collected during a field experiment in an university campus. Comparing measurements to estimates, the model seems to properly approximate the outdoor temperature and the air motion. However, a discrepancy is observed between estimates and measurements of the surface temperature. The discrepancy could be minimised if a better consideration of the net-longwave radiation was possible when co-simulating EnergyPlus. After some improvements, the model could become a support tool to mitigate urban heat islands and climate change in different regions of the world. [ABSTRACT FROM AUTHOR]

• Urban Overheating affects energy generation and demand, pollution, health and vulnerability. • It increases the energy demand for cooling and decreases the efficiency of power plants. • Rises the concentration of ground level ozone. • Increase indoor temperature in low income housing. • Increases heat related mortality and morbidity. Urban overheating is documented for more than 400 major cities in the world. Numerous experimental data show that the magnitude of the average temperature increase may exceed 4-5 C, while at the peak may exceed 10 C. Increased ambient temperatures cause a serious impact on the cooling energy consumption, peak electricity demand, heat related mortality and morbidity, urban environmental quality, local vulnerability and comfort. Synergies between urban heat island and heat waves increase further the amplitude of urban overheating The present paper reviews and reports the recent progress and knowledge on the specific impact of current and projected urban overheating in energy, peak electricity demand, air quality, mortality and morbidity and urban vulnerability. In parallel, it discusses new findings related to the characteristics and the magnitude of urban overheating, and reports and analyse the recent knowledge on the synergies between urban heat island and heat waves. [ABSTRACT FROM AUTHOR]