Papers by Stefano Corgnati
A research project aimed at investigating IAQ and thermal, acoustic and visual comfort was carrie... more A research project aimed at investigating IAQ and thermal, acoustic and visual comfort was carried out in Italian high school and university classrooms. The investigations were performed through field campaigns during regular lesson periods consisting of subjective surveys and measurements. This work focuses in analysing the results from the IAQ investigations at four high schools of Provincia di Torino during the heating period. Measurements were addressed to evaluate the air change rate through the tracer gas technique, the air permeability of the building envelope through the blower door technique and the indoor air quality through monitoring the CO2 concentration. Results from measurements were compared with the requirements from Italian standards and regulations for school buildings. At the same time, questionnaires were filled by students in order to qualify the perceived air quality.
Author(s): D'Oca, Simona; Corgnati, Stefano; Pisello, Anna L; Hong, Tianzhen | Abstract: An i... more Author(s): D'Oca, Simona; Corgnati, Stefano; Pisello, Anna L; Hong, Tianzhen | Abstract: An increasing body of research is underlying the need to foster energy behaviors and interaction with technology as a way to achieve energy savings in office buildings. However, engaging office users into more “forgiving” comfort-adaptive behavior is not a trivial task, since neither consequences nor benefits for changing behavior have visible or tangible effects on them personally. Since the 70’s, survey studies in the field of building science have been used to gain better understanding of multidisciplinary drivers of occupant behavior with respect to comfort and energy requirements in buildings. Rather than focusing on individual behaviors – and influencing factors – purpose of this survey research is to provide quantitative descriptions on the collective and social motivations within the complexity of different social groups in working environment, under different geographical context, c...
Academic literature suggests a positive relationship between environmental and financial performa... more Academic literature suggests a positive relationship between environmental and financial performance in property investments: in addition to the energy savings related to the building renovation, co-benefits can be reaped, ranging from being healthier to providing lower ownership risk. In this context, the paper describes the EU prescribed cost-optimality calculation performed for a hotel building and proposes an experimental revised version on the cost-optimal methodology, in which the co-benefits of energy retrofit are assessed and included in the calculation. An Italian existing Reference Hotel (RH) was selected as baseline model for the cost-optimal analysis. A number of Energy Efficiency Measures (EEMs) and packages of EEMs for the building envelope were applied to the RH, for which energy performances were assessed through a dynamic energy simulation software. Firstly, primary energy consumptions and global costs of the packages of EEMs were derived to identify the cost-optima...
There is extensive pressure on sustainable buildings to deliver energy efficiency, but in practic... more There is extensive pressure on sustainable buildings to deliver energy efficiency, but in practice, designs often fail to achieve the expected level of in-use energy consumption. One of the main factors behind this discrepancy between designed and real total energy use in buildings is the window opening behaviour. Towards nearly zero energy building (NZEB), building performance simulation is being increasingly deployed beyond the building design phase. With the aim to investigate how the climate affects the probabilistic model of window behaviour, the case study is simulated in different locations, i.e. Continental (Turin) and Mediterranean (Athens). Moreover, each simulated model refers to three comfort category heating and cooling set point conditions (Category I, II, III) as defined in Standard EN 15251:2006. Comparing the results, the influence of window behaviour on energy consumption in different climates generates energetically different outcomes. The present study highlights...
Any historically significant interior require speci al attention in connection with indoor climat... more Any historically significant interior require speci al attention in connection with indoor climate and air quality control, especially h dro – thermal microclimate is essential. Air temperature and relative humidity, a nd in particular their sudden fluctuation over the time, have a wide implication f r preservation. Unfortunately, in many historical interiors these parameters lie far beyond the tolerated range. In this case it is necessary to carry out measures leading to improvement conditions and, at the same time, take into account economic aspect an d he request for more and more decreasing energy consumption. Any intervention or restoration action should be preceded by a thorough analysis of current situatio n. This statement applies to all building, but for historical objects this is especi ally true. In order to proper determinate of initial conditions, monitoring in ap propriate time period has to be
In accordance with the Kyoto Protocol, the Member States of the European Union have committed the... more In accordance with the Kyoto Protocol, the Member States of the European Union have committed themselves to a process aimed at fighting climate change through the adoption of community and national decarbonization policies. For the first time, an integrated approach between energy policies and the match against climate change was foreseen with the 2020 Climate-Energy Package at EU level. Starting in 2009, a series of Directives, and furthermore recast, have followed one another with the main objective of reducing greenhouse gas emissions, increasing the share of energy produced from renewable sources and increasing energy savings (European Commission, 2002; 2010). In 2015, during the XXI Conference of the Parties to the Framework Convention for the fight against climate change held in Paris (COP 21), the Paris Agreement was adopted as confirmation of the commitment. The latest Directive 2018/844/EU (European Commission, 2018), amending Directive 2010/31/EU on the energy performance ...
Buildings' actual energy performance frequently does not meet the expectations at the design ... more Buildings' actual energy performance frequently does not meet the expectations at the design phase. One of the potential reasons for the discrepancy between expected and actual energy performance may be the uncertainties associated with building occupants' presence and behavior (e.g., operation of windows, blinds, luminaires). In this paper, we investigate the implications of different occupancy-related assumptions (pertaining to presence and window operation) on the predicted heating and cooling loads of a sample office building in Turin, Italy. Specifically, we deploy a dynamic numeric simulation application to compare standard occupancy models with probabilistic models in view of the computationally predicted heating and cooling demand of the building.
Main theme of the congress was the nZEB, especially approaches to the nZEB in these Mediterranean... more Main theme of the congress was the nZEB, especially approaches to the nZEB in these Mediterranean countries. 159 abstracts were received from not only member counties but from 21 countries in the region and all over the world. Finally 90 full papers included in the proceedings book and 66 papers presented orally during the congress and 11 posters were exposed. 22 Technical Sessions were held in 7 parallel rooms during the congress. Technical sessions were designed according to congress themes. Besides, 3 invited lectures were also presented during the congress and a panel was held. Additionally, a seminar was organized by the Eurovent. 429 participants were registered formally at the conference. Including guests and other accompanying people, more than 500 people attended the conference.
This paper shows a case study proposed in a doctoral thesis currently in progress. The thesis inv... more This paper shows a case study proposed in a doctoral thesis currently in progress. The thesis investigates the application of energy calculations to support the design process, ranging from simple energy calculation methods to detailed simulations. In the case study, the design process of an apartment building block in Spain is proposed. Different energy calculation tools are applied at each stage of the project. This paper focuses on the early stages of the design process, in which a simple modelling and calculation approach is adopted. The paper shows, by means of the discussion of the case study, the importance of key factors identified by the authors for the choice of a suitable energy calculation method during the design process.
As the residential sector in the EU is responsible for about 40% of the total energy consumption ... more As the residential sector in the EU is responsible for about 40% of the total energy consumption and up to 36% of the total carbon dioxide emissions, the residential building stock offers high potential for energy savings [1]. Among the energy efficiency targets, the existing building stock and its energy performance improvements play a crucial role, because energy use in buildings has steadily increased.
Smart Cities, 2020
The building sector is currently responsible of 40% of global final energy consumption, influenci... more The building sector is currently responsible of 40% of global final energy consumption, influencing the broader energy system in terms of new electricity and heat capacity additions, as well as distribution infrastructure reinforcement. Current building energy efficiency potential is largely untapped, especially at the local level where retrofit interventions are typically enforced, neglecting their potential synergies with the entire energy system. To improve the understanding of these potential interactions, this paper proposes a methodology that links dynamic building simulation and energy planning tools at the urban scale. At first, a detailed bottom-up analysis was conducted to estimate the current and post-retrofit energy demand of the building stock. The stock analysis is further linked to a broader energy system simulation model to understand the impact of building renovation on the whole urban energy system in terms of cost, greenhouse gas emission, and primary energy consu...
International Journal of Heat and Technology, 2017
Urban districts should evolve towards a more sustainable infrastructure and greener energy carrie... more Urban districts should evolve towards a more sustainable infrastructure and greener energy carriers. The utmost challenge is the smart integration and control, within the existing infrastructure, of new information and energy technologies (such as sensors, appliances, electric and thermal power and storage devices) that are able to provide multi-services based on multi-actors and multi and interchangeable energy carriers. In recent years, the Municipality of Torino represents an experimental scenario, in which practical experiences in the below-areas have taken place through a number of projects: 1. energy efficiency in building; 2. smart energy grids management and smart metering; 3. biowaste-to-energy: mixed urban/industrial waste management with enhanced energy recovery from biogas. This work provides an overview and update on the most interesting initiatives of smart energy management in the urban context of Torino, with an analysis and quantification of the advantages gained in terms of energy and environmental efficiency.
It is common knowledge that occupants' behaviour on building control systems plays a significant ... more It is common knowledge that occupants' behaviour on building control systems plays a significant role to achieve comfortable indoor environmental conditions. Moreover, different research studies have shown how occupants' behaviour also has a huge influence on energy consumption. Consequently, since the building sector still consumes nearly half of the total amount of energy used in Europe and because occupants' comfort should be one of the major aim of a building construction, this influential factor should be further investigated. Reliable information concerning occupants' behaviours in a building could help to better evaluate building energy performances and design robustness, as well as, it could help supporting the development of occupants' education to energy awareness. Concerning occupant behaviour related to indoor lighting systems, many studies have been made regarding occupants' feelings and performances to certain visual stimuli due to different light systems. Nevertheless, occupants' interactions with lighting control systems needs further investigation also because few models to predict switching operations have been implemented in energy simulation programmes. This study proposes probabilistic models to describe occupants' switching on-off control over lighting. They have been developed using a multivariate logistic regression based on measurements of indoor climate parameters, outdoor environmental conditions and artificial lights "switch on/off" actions. Measurements were made over eleven months for three different office rooms. Two predictive light-switch behaviour models were inferred in relation to the number of actions carried out by the users (active or passive). The models are presented and critically discussed in this paper. The study extends the information on environmental parameters influencing occupants' manual control of the lighting system in offices and energy consumption.
Buildings, 2016
The interactions between building occupants and control systems have a high influence on energy c... more The interactions between building occupants and control systems have a high influence on energy consumption and on indoor environmental quality. In the perspective of a future of "nearly-zero" energy buildings, it is crucial to analyse the energy-related interactions deeply to predict realistic energy use during the design stage. Since the reaction to thermal, acoustic, or visual stimuli is not the same for every human being, monitoring the behaviour inside buildings is an essential step to assert differences in energy consumption related to different interactions. Reliable information concerning occupants' behaviours in a building could contribute to a better evaluation of building energy performances and design robustness, as well as supporting the development of occupants' education to energy awareness. The present literature survey enlarges our understanding of which environmental conditions influence occupants' manual controlling of the system in offices and by consequence the energy consumption. The purpose of this study was to investigate the possible drivers for light-switching to model occupant behaviour in office buildings. The probability of switching lighting systems on or off was related to the occupancy and differentiated for arrival, intermediate, and departure periods. The switching probability has been reported to be higher during the entering or the leaving time in relation to contextual variables. In the analysis of switch-on actions, users were often clustered between those who take daylight level into account and switch on lights only if necessary and people who totally disregard the natural lighting. This underlines the importance of how individuality is at the base of the definition of the different types of users.
Energy Procedia, 2015
Literature studies confirm occupant behavior is setting the direction for contemporary researches... more Literature studies confirm occupant behavior is setting the direction for contemporary researches aiming to bridge the gap between predicted and actual energy performance of sustainable buildings. Using the Knowledge Discovery in Database (KDD) methodology, two data mining learning processes are proposed to extrapolate office occupancy and windows' operation behavioral patterns from a two-years data set of 16 offices in a natural ventilated office building. Clustering procedures, decision tree models and rule induction algorithms are employed to obtain association rules segmenting the building occupants into working user profiles, which can be further implemented as occupant behavior advanced-inputs into building energy simulations.
The interactions between building occupants and control systems have a high influence on energy c... more The interactions between building occupants and control systems have a high influence on energy consumption and on internal environmental quality. In the perspective of a future of "nearly-zero" energy buildings, it is crucial to analyse the energy-related interactions deeply to predict a realistic energy use during the design stage. Since the reaction to thermal, acoustic or visual stimulus is not the same for every human being, monitoring the behaviour inside buildings is an essential step to assert differences in energy consumption related to different interactions. Based on measurements in eight offices in Prague, seven models concerning occupants' window opening behaviour in office buildings were proposed. The dataset was gathered through a monitoring campaign lasting 11 months, from February 2012 until January 2013. Indoor and outdoor environmental conditions were collected in eight southwest exposed rooms, mechanically ventilated and heated through radiators. Two rooms were used by two people while the other six were single offices. Seven models for opening and closing windows were inferred using multiple logistic regression. The model's outputs were probabilities of a window opening and window closing event within the next five minutes. Implementing all the models into dynamic energy simulation software would lead to different simulated behaviour patterns and consequently different demands and uses of energy, representing a more reliable variability of energy consumption due to building occupants'.
Energy consumption in buildings is influenced by building properties, building controls and the w... more Energy consumption in buildings is influenced by building properties, building controls and the way that these are used by the occupants of the building. This paper focuses on natural ventilation concerning the occupants' habits of opening/closing the windows in residential buildings. Preeminent variables influencing the occupants' use of windows are investigated and the main results of a literature review are highlighted. Statistical analysis of data coming from measurements of occupants' window opening, conducted in 15 dwellings in Denmark, are developed to infer the probability of opening and closing windows and to determine relationships between environmental conditions and the occupants' window opening behaviour. The main physical environmental variables that have been found to be important drivers in determining the action to open or close windows are defined on the basis of the measurements. The ultimate goal is to provide more accurate information about drivi...
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Papers by Stefano Corgnati