1,721,009 research outputs found
Towards energy efficient, comfortable and climate resilient built environment: Development and application of smart, optimized and mitigation-oriented solutions
Get PDFQuesta tesi riporta una serie di attività di ricerca che indagano, sotto diversi aspetti spaziali e temporali, i temi di efficienza energetica, comfort e resilienza al cambiamento climatico relativi al settore edilizio. Il primo macroblocco tematico è incentrato sul design di logiche di controllo ottimizzate a servizio di svariati componenti edilizi, nella fattispecie: radiatori elettrici (logiche on-off, PID e fuzzy), finestre (algoritmi di comfort adattivi basati su qualità dell’aria e comfort termico), serre solari (ventilazione meccanica controllata a logica termoigrometrica) e ventilconvettori (modelli fuzzy e predittivi per la gestione degli apporti solari). Il secondo macroblocco indaga le ripercussioni del cambiamento climatico sulla performance energetica ed ergonomica dell’ambiente costruito, partendo dal singolo edificio fino a coinvolgere fenomenologie su scala urbana. Vengono dapprima presentati i risultati dello studio di quattro mesi condotto su territorio europeo nell’ambito dell’edizione 2015 del WISBA (Wienerberger Sustainable Building Academy): la resilienza di un edificio low-tech (rappresentato dal Building 2226, Austria) è investigata nel contesto delle condizioni climatiche attese nel 2050 per approdare ad una strategia di redesign anti obsolescenza prematura. In seguito, sono esposti e discussi i risultati di uno dei progetti di mitigazione dell’effetto isola di calore urbana, condotti in collaborazione con la University of New South Wales (Sydney, Australia): il caso limite rappresentato da una capitale tropicale (Darwin) è oggetto di monitoraggio, analisi, modellazione e sviluppo di contromisure specifiche. Nel complesso, l’intero percorso di ricerca mira a definire e testare su campo soluzioni ad elevato potenziale di risparmio energetico e comfort (indoor ed outdoor) tramite logiche smart e tecnologie orientate alla mitigazione dei fenomeni di surriscaldamento globale. Comun denominatore è l’inclusione di una robusta fase sperimentale.This thesis addresses a series of research activities spanning the different spatial and temporal aspects of energy efficiency, comfort and climate change resilience throughout diverse scales of the built environment.
The first macro-topic deals with the design of optimized control logics of specific building components, notably: electric radiators (on-off, PID and fuzzy controllers), windows (indoor air quality and thermal comfort driven adaptive comfort algorithm), sunspaces (smartly controlled mechanical ventilation) and fan coil units (fuzzy and model-predictive logics to counteract overabundant solar gains).
The second macro-topic focuses on how climate change phenomena impinge on the energetic and ergonomic performance of buildings and cities.
Firstly, the outcomes of the four-month experience in Europe, as a member of the 2015 WISBA edition (Wienerberger Sustainable Building Academy), are presented: the low-tech concept of Building 2226 (Austria) was tested in the frame of the actual climatic conditions and in view of the expected climate change to come in 2050. A re-design strategy was developed to enhance its resilience.
Secondly, the results of one of the Urban Heat Island (UHI) mitigation projects run during the last year in collaboration with the University of New South Wales (Sydney, Australia) are illustrated and discussed: the borderline case of a tropical city (Darwin, Northern Territory) was monitored, analysed, modelled and tackled by developing customized counterbalance measures.
Indeed, the overarching aim of the whole research path is to provide and field-test smart, optimized and mitigation-oriented solutions towards more efficient and liveable indoor and outdoor spaces. Special focus was given to the collection of on-site validated data, by planning robust monitoring campaigns and properly selecting the sensor networks
Sunspace coupling with hyper-insulated buildings: Investigation of the benefits of heat recovery via controlled mechanical ventilation
No full textIndoor air quality and thermal comfort optimization in classrooms developing an automatic system for windows opening and closing
Get PDFThermal comfort and indoor air quality in school classrooms are essential requirements to promotestudents’ productivity and reduce health symptoms. This paper presents the development of an automaticsystem for window openings, based on thermal comfort and indoor air quality correlations. The researchwas carried out in two adjacent classrooms. The initial phase aimed at assessing environmental conditionsin classrooms, testing objective and subjective comfort models and establishing trigger parameters forwindow opening events; the second phase regarded the implementation of an adaptive control algorithmin an automatic system piloting windows with the aim of maintaining a satisfactory environment bothin terms of IAQ and thermal comfort. The main results show that: (1) the IAQ is a relevant issue in schoolclassrooms, because students usually suffer high CO2levels; (2) the stronger driving force for undertakingadaptive actions is thermal comfort, while the need to improve the air quality is a secondary constraint;(3) the mechanized system ensures a good quality in terms of IAQ, thermal comfort and users’ satisfaction
Comfort e qualità dell’aria per scuole smart: un innovativo sistema di apertura automatizzata delle finestre
No full textLocalized synergies between heat waves and urban heat islands: Implications on human thermal comfort and urban heat management
No full textHeat waves (HWs) and urban heat islands (UHIs) can potentially interact. The mechanisms behind their synergy are not fully disclosed. Starting from the localized UHI phenomenon, this study aims i) to reveal their associated impacts on human thermal comfort through three different definitions of HW events, based on air temperature (airT), wet-bulb globe temperature (WBGT) and human-perceived temperature (AppT) respectively, and ii) to understand the role of air moisture and wind. The analysis was conducted in four districts (NH, JD, MH and XJH) with different urban development patterns and geographic conditions, in the megacity of Shanghai with a subtropical humid climate. Results evidenced the localized interplay between HWs and UHIs. The results indicate that less urbanized districts were generally more sensitive to the synergies. JD district recorded the highest urban heat island intensity (UHII) amplification, regardless of the specific HW definition. Notably, during AppT-HWs, the increment was observed in terms of maximum (1.3 °C), daily average (0.8 °C), diurnal (0.4 °C) and nocturnal UHII (1.0 °C). Nevertheless, localized synergies between HWs and UHIs at different stations also exhibited some commonalities. Under airT-HW, the UHII was amplified throughout the day at all stations. Under WBGT-HW, diurnal UHII (especially at 11:00–17:00 LST) was consistently amplified at all stations. Under AppT-HW conditions, the nocturnal UHII was slightly amplified at all stations. Air moisture and wind alleviated the synergistic heat exacerbation to the benefit of thermal comfort. The extent depended on geographic condition, diurnal and nocturnal scenarios, temperature type and HW/normal conditions. Stronger HW-UHI synergies indicate the necessity to develop specific urban heat emergency response plans, able to capture and intervene on the underlying mechanisms. This study paves to way to their identification
Comparing the performance of on/off, PID and fuzzy controllers applied to the heating system of an energy-efficient building
No full textExperimental monitoring of a sunspace applied to a NZEB mock-up: Assessing and comparing the energy benefits of different configurations
No full textOverheating phenomena induced by fully-glazed facades: Investigation of a sick building in Italy and assessment of the benefits achieved via model predictive control of the AC system
No full textCombining artificial intelligence and building engineering technologies towards energy efficiency: the case of ventilated façades
Get PDFPurpose
Nearly 75% of EU buildings are not energy-efficient enough to meet the international climate goals, which triggers the need to develop sustainable construction techniques with high degree of resilience against climate change. In this context, a promising construction technique is represented by ventilated façades (VFs). This paper aims to propose three different VFs and the authors define a novel machine learning-based approach to evaluate and predict their energy performance under different boundary conditions, without the need for expensive on-site experimentations
Design/methodology/approach
The approach is based on the use of machine learning algorithms for the evaluation of different VF configurations and allows for the prediction of the temperatures in the cavities and of the heat fluxes. The authors trained different regression algorithms and obtained low prediction errors, in particular for temperatures. The authors used such models to simulate the thermo-physical behavior of the VFs and determined the most energy-efficient design variant.
Findings
The authors found that regression trees allow for an accurate simulation of the thermal behavior of VFs. The authors also studied feature weights to determine the most relevant thermo-physical parameters. Finally, the authors determined the best design variant and the optimal air velocity in the cavity.
Originality/value
This study is unique in four main aspects: the thermo-dynamic analysis is performed under different thermal masses, positions of the cavity and geometries; the VFs are mated with a controlled ventilation system, used to parametrize the thermodynamic behavior under stepwise variations of the air inflow; temperatures and heat fluxes are predicted through machine learning models; the best configuration is determined through simulations, with no onerous in situ experimentations needed
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