Field occupants’ behavior monitoring integrated to prediction models: impact on building energy performance

Given the massive scientific progress on passive and active solutions to reach near-zeroenergy targets, the necessity to consider occupants’ behavior as a key variable affecting field energy performance of buildings has become a crucial issue to face. In this panorama, a variety of deterministic and stochastic models, also supported by experimental investigations have been developed in the last decade. This paper builds upon previous contributions to analyze the real occupancy of an office building populated by peers’ offices monitored for 2 years by means of microclimate and energy-need field stations. After demonstrating that the peers do not behave the same and do not control in equivalent ways indoors microclimate parameters (e.g. air temperature, desk illuminance, etc.), internationally acknowledged models and field-collected data are compared through dynamic simulation. The estimation of final energy need of different considered scenarios is calculated and the relative difference is highlighted as a possible indicator about the role of building occupancy profiles in affecting energy need prediction. Additionally, EEG experimental test are used to assess the correlation of workers’ subjective emotions with external thermal stimuli. Results of final energy need estimation showed to vary by about 20% by only selecting the occupancy simulation scheme, and non-consistent prediction trends are found out while investigating lighting and electric appliances needs. Accordingly, as concerns the human psychological response to the variation of thermal conditions, negligible emotional reactions are found among the different tested workers when suddenly altering comfort conditions indoors

Cool Roof Impact on Building Energy Need: The Role of Thermal Insulation with Varying Climate Conditions

Cool roof effectiveness in improving building thermal-energy performance is affected by different variables. In particular, roof insulation level and climate conditions are key parameters influencing cool roofs benefits and whole building energy performance. This work aims at assessing the role of cool roof in the optimum roof configuration, i.e., combination of solar reflectance capability and thermal insulation level, in terms of building energy performance in different climate conditions worldwide. To this aim, coupled dynamic thermal-energy simulation and optimization analysis is carried out. In detail, multi-dimensional optimization of combined building roof thermal insulation and solar reflectance is developed to minimize building annual energy consumption for heating-cooling. Results highlight how a high reflectance roof minimizes annual energy need for a small standard office building in the majority of considered climates. Moreover, building energy performance is more sensitive to roof solar reflectance than thermal insulation level, except for the coldest conditions. Therefore, for the selected building, the optimum roof typology presents high solar reflectance capability (0.8) and no/low insulation level (0.00-0.03 m), except for extremely hot or cold climate zones. Accordingly, this research shows how the classic approach of super-insulated buildings should be reframed for the office case toward truly environmentally friendly buildings.The work was partially funded by the Spanish government (RTI2018-093849-B-C31). This work was partially supported by ICREA under the ICREA Academia programme. Dr. Alvaro de Gracia has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 712949 (TECNIOspring PLUS) and from the Agency for Business Competitiveness of the Government of Catalonia. This publication has emanated from research supported (in part) by Science Foundation Ireland (SFI) under the SFI Strategic Partnership Programme Grant Number SFI/15/SPP/E3125

Outdoor thermal and visual perception of natural cool materials for roof and urban paving

Given the acknowledged thermal performance of natural light color gravels applied as cool roof and cool urban paving, this work is aimed at investigating if such behavior is perceivable by pedestrians, who are questioned in this paper about their visual and thermal comfort perception. In fact, there are still related aspects to analyze, in order to optimize their application and provide a comfortable space for users, both on the thermal and the visual point of view. Therefore, the question that this work wants to answer is: given their intrinsic characteristics, do these materials create a sensitive thermally and visually more comfortable environment for pedestrians? In order to address this uninvestigated issue, users’ judgment about visual and thermal comfort of these surfaces is considered, also by comparing them with grassland and asphalt. Also, the statistical correspondence between physical properties of such materials and possible correspondence with respect to human perception with varying weather conditions is analyzed. Given the relatively high reflectance of these materials, it appears particularly important to evaluate these aspects, to consciously apply them as urban paving or roof covering by optimizing their natural passive cooling potential. In this preliminary study, users’ response to these surfaces is evaluated by mean of field surveys, both on the thermal and the visual evaluation, and contemporary in-field measurements of surface parameters. Also, human perception with respect to these high-reflectance surfaces’ is compared with the one related to grassland and asphalt, with varying weather conditions. Then, a statistical analysis is performed to investigate the differences among different gravels, grassland and asphalt, based on surveys’ results. The results show how pedestrians, questioned during summer days, prefer grassland, while asphalt is the less favorite surface both visually and thermally; there is a small difference between gravels’ types evaluation, while weather variability affect the preferences

Greenery System for Cooling Down Outdoor Spaces: Results of an Experimental Study

Urban green infrastructure (UGI) and nature-based solutions (NBS) are increasingly recognized as strategies to address urban sustainability challenges. These solutions are attracting key scientific and marketing attention thanks to their capability to improve indoor and outdoor thermal comfort and environmental quality of spaces. In urban areas, where most of the population worldwide lives, indoor-outdoor environmental quality is compromised by local and temporary overheating phenomena, air pollution concentration, and impervious surfaces minimizing urban space resilience to climate change related hazards. In this view, the proposed study concerns the analysis of a greenery system for enhancing outdoor thermal conditions and local warming mitigation for pedestrians for the continental Mediterranean climate. The system has the purpose of designing an outdoor 'alive' shading system to be applied in open public spaces, with producing physical and societal benefits. The experimental results showed that the implementation of the greenery, characterized by lower surface temperatures and evapotranspiration compared to a simple pergola system, allows the reduction of outdoor air temperature under the shading system and, thus, higher relative humidity in summer. Specifically, the hygrothermal cooling and the additional shading thanks to the presence of greenery provide local air temperature reduction up to 5 C at pedestrian level.Funding: This work was partially funded by the Ministerio de Ciencia, Innovación y Universidades de España (RTI2018-093849-B-C31 - MCIU/AEI/FEDER, UE). This work was partially funded by the Ministerio de Ciencia, Innovación y Universidades - Agencia Estatal de Investigación (AEI) (RED2018-102431-T). The authors from University of Perugia thank Fondazione Cassa di Risparmio di Perugia for supporting the investigation about biomaterials within the project SOS CITTÁ 2018.0499.026. Acknowledgments: The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2017 SGR 1537). GREiA is a certified agent TECNIO in the category of technology developers from the Government of Catalonia. This work is partially supported by ICREA under the ICREA Academia programme

Thermal comfort in the historical urban canyon: the effect of innovative materials

Urban heat island (UHI) can considerably affect the thermal quality of the urban environment, especially within urban canyons, that have typically low sky view factor and limited surface heat re-emission capability. A huge research effort has been registered to develop mitigation solutions for UHI, such as cool materials and greenery. Nevertheless, it is not always possible to apply such strategies in historical urban environments due to constrains for the preservation of their cultural value that do not allow to modify the exterior architectural appearance of heritage buildings. In this scenario, the present paper deals with the analysis of the potential of innovative cool materials characterized by the same appearance of historical ones in mitigating the UHI occurring in the context of a historical urban canyon located in central Italy selected as pilot case study. To this purpose, a preliminary experimental characterization of such innovative highly reflective materials has been performed. Afterwards, an experimental continuous monitoring campaign of the main outdoor microclimate parameters and a numerical modelling of the canyon have been carried out to evaluate the local mitigation capability of such materials when applied over the vertical and horizontal surfaces of the historical canyon. The results show the huge potential of the proposed innovative cool materials in mitigating the local microclimate of the historical urban canyon. In fact, a MOCI reduction up to 0.15 and 0.30 is detected by applying cool red envelope materials and cool red envelope materials plus cool grey paving materials, respectively, on the canyon surfaces

Bio-inspired outdoor systems for enhancing citizens thermal comfort in public spaces by learning from nature

In the last decades a variety of high-energy efficient solutions for building envelopes were developed and tested for enhancing indoor thermal comfort and improving indoor environmental quality of private spaces by learning from nature. To this aim, adaptive solutions, conceived thanks to green and bio inspiration, were designed and constructed in various climate conditions and for a variety of building uses. Given the huge population flow toward urban areas, well-being conditions in the public spaces of such dense built environment are being compromised, also due to anthropogenic actions responsible for massive environmental pollution, local overheating, urban heat island, etc. Moreover, this process is exacerbated by temporary phenomena such as heat waves. Therefore, outdoor spaces are becoming increasingly less comfortable and even dangerous for citizens, especially if they are affected by general energy poverty, with no chance for active systems management for air conditioning, or health vulnerability. In this view, this study concerns the first concept for the development of a simple and adaptive nature-inspired solution for outdoor thermal comfort enhancement and local overheating mitigation for pedestrians. The system will be evaluated in terms of the cradle-to-cradle approach and the initial performance assessment is carried out via thermal-energy dynamic simulation. The final purpose will be to design outdoor “alive” shading system to be applied in open public spaces, with evident physical and social benefits

Optimization of coupled building roof solar reflectance and thermal insulation level for annual energy saving under different climate zones

The aim of this work is to assess building energy performance optimization potential of cool roof solutions in different climate conditions worldwide through dynamic thermal-energy simulation and optimization analysis. Moreover, given the dependence of roof performance on insulation level, the influence of roof insulation variation on optimum roof solar reflectance is evaluated. Therefore, the multi-dimensional optimization of combined building roof solar reflectance capability and thermal insulation level is carried out to minimize annual energy consumption for air-conditioning of standard ASHRAE building model for small offices, in each considered climate zone. Findings of this research highlight how the classic approach of super-insulated buildings for energy saving needs to be reframed for the office case, by integrating other passive solutions for truly environmentally friendly and comfortable buildings.The research leading to these results has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement N°657466 (INPATH-TES). The work is partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER) and ENE2015-64117-C5-3-R (MINECO/FEDER)). The authors from the University of Lleida would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123). Anna Laura Pisello’s acknowledgments are due to the UNESCO Chair “Water Resources Management and Culture”, for supporting her research. Alvaro de Gracia would like to thank Ministerio de Economia y Competitividad de España for Grant Juan de la Cierva, FJCI-2014-19940

Measurement and verification of zero energy settlements: Lessons learned from four pilot cases in Europe

Measurement and verification (M&V) has become necessary for ensuring intended design performance. Currently, M&V procedures and calculation methods exist for the assessment of Energy Conservation Measures (ECM) for existing buildings, with a focus on reliable baseline model creation and savings estimation, as well as for reducing the computation time, uncertainties, and M&V costs. There is limited application of rigorous M&V procedures in the design, delivery and operation of low/zero energy dwellings and settlements. In the present paper, M&V for four pilot net-zero energy settlements has been designed and implemented. The M&V has been planned, incorporating guidance from existing protocols, linked to the project development phases, and populated with lessons learned through implementation. The resulting framework demonstrates that M&V is not strictly linked to the operational phase of a project but is rather an integral part of the project management and development. Under this scope, M&V is an integrated, iterative process that is accompanied by quality control in every step. Quality control is a significant component of the M&V, and the proposed quality control procedures can support the preparation and implementation of automated M&V. The proposed framework can be useful to project managers for integrating M&V into the project management and development process and explicitly aligning it with the rest of the design and construction procedures