Improving energy modeling of large building stock through the development of archetype buildings

12th Conference of International Building Performance Simulation Associatio

Evolution of magnetic fields and energetics of flares in active region 8210

To better understand eruptive events in the solar corona, we combine sequences of multi-wavelength observations and modelling of the coronal magnetic field of NOAA AR 8210, a highly flare-productive active region. From the photosphere to the corona, the observations give us information about the motion of magnetic elements (photospheric magnetograms), the location of flares (e.g., H$\alpha$, EUV or soft X-ray brightenings), and the type of events (H$\alpha$ blueshift events). Assuming that the evolution of the coronal magnetic field above an active region can be described by successive equilibria, we follow in time the magnetic changes of the 3D nonlinear force-free (nlff) fields reconstructed from a time series of photospheric vector magnetograms. We apply this method to AR 8210 observed on May 1, 1998 between 17:00 UT and 21:40 UT. We identify two types of horizontal photospheric motions that can drive an eruption: a clockwise rotation of the sunspot, and a fast motion of an emerging polarity. The reconstructed nlff coronal fields give us a scenario of the confined flares observed in AR 8210: the slow sunspot rotation enables the occurence of flare by a reconnection process close to a separatrix surface whereas the fast motion is associated with small-scale reconnections but no detectable flaring activity. We also study the injection rates of magnetic energy, Poynting flux and relative magnetic helicity through the photosphere and into the corona. The injection of magnetic energy by transverse photospheric motions is found to be correlated with the storage of energy in the corona and then the release by flaring activity. The magnetic helicity derived from the magnetic field and the vector potential of the nlff configuration is computed in the coronal volume. The magnetic helicity evolution shows that AR 8210 is dominated by the mutual helicity between the closed and potential fields and not by the self helicity of the closed field which characterizes the twist of confined flux bundles. We conclude that for AR 8210 the complex topology is a more important factor than the twist in the eruption process

National scientific report on the TABULA activities in Italy

The Italian contribution to the TABULA research project is decribed. Ii was addressed to: - the development of the harmonised structure for the Italian typology and the supply of input data on buildings, constructions and systems (heating and DHW), which constitute the main data for the webtool; - the application of the typology concept for the assessment of the energy performance of residential buildings and for the evaluation of the impact of energy conservation measures, through the calculation of the energy performance of the building-types; - the use of the typology concept to create a model for the estimation of the national energy balance of the residential building stock by the support of national statistical dat

Building Typology Brochure - Italy. Fascicolo sulla Tipologia Edilizia Italiana

Si illustra la struttura della tipologia edilizia nazionale sviluppata nell'ambito del progetto europeo TABULA, con particolare riferimento alla definizione degli edifici-tipo per la zona climatica compresa tra 2100 a 3000 gradi-giorno, che rappresenta il 52% dei comuni italiani. Sono inoltre presentati i dati relativi alla tipologia costruttiva e impiantistica italiana. Una sezione specifica del libro, organizzata sottoforma di schede illustrative, è dedicata all'analisi energetica degli edifici-tipo, con l'indicazione del risparmio energetico conseguibile a seguito di interventi di riqualificazione sull'involucro edilizio e sull'impianto termic

The Impact of Window Operation Assumptions on the Thermal Simulation Results of an Office Building

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

Application of Building Typologies for Modelling the Energy Balance of the Residential Building Stock

Building typologies can serve as a basis for analysing the national housing sector. During the TABULA project which was introducing or further developing building typologies in thirteen EU countries, six of the European partners have carried out model calculations which aim at imaging the energy consumption and estimating the energy saving potentials of their national residential building stocks (IWU / Germany, NOA / Greece, POLITO / Italy, VITO / Belgium, STU-K / Czech Republic, SBi / Denmark). The results show that the model calculations can provide plausible projections of the energy consumption of the national residential buildings stock. The fit of model calculations and national energy statistics is satisfactory, deviations can often be explained and corrected by adapting standard boundary conditions of the applied calculation models to more realistic values. In general, the analysis shows that building typologies can be a helpful tool for modelling the energy consumption of national building stocks and for carrying out scenario analysis beyond the TABULA project. The consideration of a set of representative buildings makes it possible to have a detailed view on various packages of measures for the complete buildings stock or for its sub-categories. The effects of different insulation measures at the respective construction elements as well as different heat supply measures including renewable energies can be considered in detail. The quality of future model calculations will depend very much on the availability of statistical data. For reliable scenario analysis information is necessary about the current state of the building stock (How many buildings and heating systems have been refurbished until now?) and about the current trends (How many buildings and heating systems are being refurbished every year?). The availability and regular update of the relevant statistical data will be an important basis for the development and evaluation of national climate protection strategies in the building secto

Profiling Occupant Behaviour in Danish Dwellings using Time Use Survey Data - Part I: Data Description and Activity Profiling

The human interaction with the building is a key cause of uncertainty when predicting energy consump- tion of buildings. Building occupants affect building energy use directly and indirectly by interacting with building energy systems, for example, by adjusting thermostats, switching lights on/off, using electri- cal devices and opening/closing windows. The occupants’ daily activity profiles and occupancy patterns clearly shape the timing and magnitude of energy demand in households. Modelling energy-related hu- man activities throughout the day, therefore, is a crucial task for prediction of energy use and, conse- quently, to reduce the gap between real and predicted building energy use. This study modelled data gathered in the diary-based Danish Time Use Survey (TUS) 2008/09 of 9640 individuals from 4679 households. Individuals’ daily activities were logged in 10-min time increments for 24 h, starting and ending at 04:00, during both weekdays and weekends. The aims of this study were to (i) profile energy-related daily activities of occupants during different seasons and weekdays/weekends (ii) investigate time-related characteristics of activities such as starting and ending times and durations, and (iii) profile occupancy patterns for weekdays/weekends for different household types. The outcomes provide valuable input for building energy simulation for bridging the gap between simulated and real energy consumption in the Danish residential sector; typical occupancy profiles for different household types for different days of the week are freely available online[1]