Stochastic assessment of the energy performance of buildings (original) (raw)

Energy performance of buildings : bridging the gap between research and practice

2016

A method to bridge the gap between research and practice, as far as estimation of the building envelope Heat Loss Coefficient is concerned, is to perform measurement of indoor temperature profiles during unoccupied periods when the solar heat gains are sufficient to reach significant indoor-outdoor temperature differences. An observation of indoor temperature profiles was conducted during summer 2014 in a passive house located in Belgium. The observation includes periods with and without occupancy. Occupants were asked to describe their behavior regarding windows opening, closing of external blinds, opening of internal doors. Electric devices were listed and the electricity consumption profile was characterized during occupancy and no occupancy. A calibration process is performed in order to reproduce the global heat balance of the whole building and the zone by zone heat balance. The calibrated model provides an estimation of the Building Heat Loss Coefficient. The influence of the...

Energy Performance and comfort in residential buildings: Sensitivity for building parameters and occupancy

Energy performance simulation is a generally used method for assessing the energy consumption of buildings. Simulation tools, though, have shortcomings due to false assumptions made during the design phase of buildings, limited information on the building's envelope and installations and misunderstandings over the role of the occupant's behaviour. This paper presents the results of a Monte Carlo sensitivity analysis on the factors (relating to both the building and occupant behaviour) that affect the annual heating energy consumption and the PMV comfort index. The PMV results are presented only for the winter (heating) period which is important for energy consumption in Northern Europe. The reference building (TU Delft Concept House) was simulated as both a Class-A and a Class F dwelling and with three different heating systems. If behavioural parameters are not taken into account, the most critical parameters affecting heating consumption are the window U value, window g value and wall conductivity. When the uncertainty of the building-related parameters increases, the impact of the wall conductivity on heating consumption increases considerably. The most important finding was that when behavioural parameters like thermostat use and ventilation flow rate are added to the analysis, they dwarf the importance of the building parameters. For the PMV comfort index the most influential parameters were found to be metabolic activity and clothing, while the thermostat had a secondary impact.

Energy Performance Assessment of Existing Dwellings

2007

The existing buildings stock in European countries accounts for over 40% of final energy consumption in the European Union (EU) member states, of which residential use represents 63% of total energy consumption in the buildings sector. Consequently, an increase of building energy performance can constitute an important instrument in the efforts to alleviate the EU energy import dependency and comply with the Kyoto Protocol to reduce carbon dioxide emissions. This is also in accordance to the European Directive on the energy performance of buildings (EPBD), which has come to effect on 4 January 2006. The energy performance assessment for existing dwellings (EPA-ED) is a new methodology supported by software, developed in the framework of a European project that focuses on energy related issues for existing residential buildings, in line with the EPBD. This paper presents an overview of the method and software that can be used to perform building energy audits and assess buildings in a uniform way, perform demand and savings calculations, provide owners with specific advice for measures to improve energy performance, issue an energy performance certificate for existing buildings, and include some representative results from the pilot studies performed in several European countries. Also the sister-method EPA-NR, on non-residential buildings, currently under construction, is introduced.

Long term evaluation of building energy performance: comparison of the test reference year and historical data series in the North Italian climates

The pursuit of better energy performance of buildings led to the recourse to more detailed instruments of analysis, requiring more complex and detailed inputs, such as the hourly weather data. In this work, the representativeness of the test reference year (TRYEN) weather data, recently developed in Italy in accordance with the procedure proposed by EN ISO 15927-4:2005, has been studied evaluating the energy performance – energy needs and peak loads – of a set of different simplified reference buildings by means of TRNSYS simulation code, using both the TRYEN and the TRYEN source multi-year collected weather series for 5 north Italian locations. The results have been analysed by means of both descriptive and inferential statistics. The variability of energy performance has also been correlated with the envelope characteristics, in order to estimate a sensitivity of the different buildings to the weather data variability.

Effects of energy efficiency measures on building performance: an analysis in seven European cities

IOP Conference Series: Materials Science and Engineering, 2019

This work presents the energy performance analysis of an autarkic residential building, located in the suburb of L’Aquila, in central Italy. The analysis is performed via a calibrated dynamic thermal model, carried out with EnergyPlusTM engine coupled with DesignBuilder. The aim of this study is the further understanding of the optimization margins of the energy self-sufficient building by considering different Energy Efficiency Measures and the effects obtainable in different climatic conditions. Four Italian cities and three European capitals are considered, in addition to different scenarios, characterized by various technological plants. In fact, a significant difference between the high efficiency of the envelope, and the poor performance of the heating system was observed. The results highlighted the remarkable energy performance optimization of the analyzed building, although the effects of the Energy Efficiency Measures showed notable differences between colder and warmer cl...