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

Data-Driven Approach to Forecast Heat Consumption of Buildings with High-Priority Weather Data

By increasing the penetration of renewable energies in district heating (DH), the intermittency of the supply-side increases for heating service providers. Therefore, forecasting the energy consumption of buildings is needed in order to hedge against renewable power intermittency. This paper investigates the application of data-driven approaches to forecast the heat consumption of buildings in the winter, using high-priority weather data. The residential buildings are connected to mixing loops of DH to supply space heating and hot water. The heating consumption of the building is calculated using sensor data, including inflow/outflow temperature and mass flow. Principal component analysis (PCA) is applied to determine the key weather data affecting heat energy consumption. Then, the study compares the competences of artificial neural networks (ANNs), linear regression models (LRM), and k-nearest neighbors (k-NN) in forecasting heat consumption, using informative data. Based on the PCA analysis, ambient temperature and solar irradiation are shown to be the highest priority weather data, contributing to 40.6% and 29.2% of heat energy forecasting, respectively. Furthermore, the ANN exhibits a forecasting accuracy of more than 50% higher than LRM and k-NN

EU-28 Residential Heat Supply and Consumption:Historical Development and Status

EU is moving towards a climate neutrality goal in 2050 with heating of buildings posing a major challenge. This paper provides a deep understanding of the historical development, path dependency and current status of the EU-28 residential heat sectors to inform strategy and policy makers and to open up this black box. Data is combined for buildings, installed technologies, fuel consumption and energy supply for Member States from 1990 to 2015, to analyse the importance of large-scale infrastructures and supply chains. Primary energy supply for residential heating is mainly based on fossil fuels; 70% in 2015 with 69% imported. The building level technologies are dominated by non-condensing boilers and stoves. Primary and final energy consumption decreased in spite of an increase in the total occupied living area in most countries. Path-dependency effects are found in the residential heat supply in EU. The analysis show path-dependent trajectories are present in most Member States, especially regarding natural gas infrastructure. The period shows many options for decarbonisation are not used to the full potential, e.g., energy efficiency in buildings, district heating, heat pumps. Past experiences should be considered when developing new decarbonisation strategies in Member States and on the EU level

Optimal sizing of solar-assisted heat pump systems for residential buildings

This paper analyzes the optimal sizing of a particular solution for renewable energy residential building integration. The solution combines a photovoltaic (PV) plant with a heat pump (HP). The idea is to develop a system that permits the maximum level of self-consumption of renewable energy generated by using a small-scale solar array installed on the same building. The problem is analyzed using data obtained from an experimental system installed in a building in Pisa, Italy. The residential house was equipped with a PV plant (about 3.7 kW of peak power), assisting a HP of similar electrical power (3.8 kW). The system was monitored for eight years of continuous operation. With reference to the data acquired from the long-term experimental analysis and considering a more general perspective, we discuss criteria and guidelines for the design of such a system. We focus on the possibility of exporting energy to the electrical grid, from the perspective of obtaining self-consumption schemes. Considering that one of the problems with small-scale PV plants is represented by the bidirectional energy flows from and to the grid, possible alternative solutions for the design are outlined, with both a size reduction in the plant and utilization of a storage system considered. Different design objectives are considered in the analysis

Thermodynamic sustainability assessment for heating of residential building

More than one third of the world's primary energy demand refers to residential sector. Heating is considered as one of the main part of the energy consumption in buildings. In this study, a thermodynamic sustainability assessment analysis of different energy sources for heating of residential building, with net floor heated area of 162 m2, for Belgrade weather data, was presented. Five options of energy sources were studied, namely: coal, natural gas, electricity, district heating and air-water heat pump. Energy and exergy analyses were conducted and appropriate efficiencies were determined. Energy and exergy flows in boundaries of the building and in the whole chain from primary to final values were analyzed. The environmental impact factor and exergetic sustainability index were determined for all considered energy sources. The exergy efficiency is very low in all analyzed cases, which further implies poor thermodynamic compatibility of energy quality from the supplied side and the energy used for building heating. It was shown that the highest exergy efficiency is for the case of heat pump utilization (about 6%), due to the energy used from environment. The minimum environmental impact factor (15.37) and maximum exergetic sustainability index (0.065) were found for the case of heat pump utilization

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 sector

Estimation of the Heat Loss Coefficient of Two Occupied Residential Buildings through an Average Method

The existing performance gap between the design and the real energy consumption of a building could have three main origins: the occupants’ behaviour, the performance of the energy systems and the performance of the building envelope. Through the estimation of the in-use Heat Loss Coefficient (HLC), it is possible to characterise the building’s envelope energy performance under occupied conditions. In this research, the estimation of the HLC of two individual residential buildings located in Gainsborough and Loughborough (UK) was carried out using an average method. This average method was developed and successfully tested in previous research for an occupied four-story office building with very different characteristics to individual residential buildings. Furthermore, one of the analysed residential buildings is a new, well-insulated building, while the other represents the old, poorly insulated semidetached residential building typology. Thus, the monitored data provided were filtered in order to apply the abovementioned average method. Even without fulfilling all the average method requirements for these two residential buildings, the method provides reliable HLC values for both residential buildings. For the house in Gainsborough, the best estimated HLC value was 60.2 W/K, while the best approach for Loughborough was 366.6 W/K. Thus, despite the uncertainty sources found during the analysis, the method seems promising for its application to residential buildings.This work was supported by the Spanish Ministry of Science, Innovation and Universities and the European Regional Development Fund through the MONITHERM project “Investigation of monitoring techniques of occupied buildings for their thermal characterization and methodology to identify their key performance indicators”, project reference: RTI2018-096296-B-C22 and -C21 (MCIU/AEI/FEDER, UE)

Comparison refurbishment models of district heating networks

The renovation of multi-storey residential buildings reduces heat consumption intensity and decreases heat demand, which may have a harmful effect on a district heating supply system. The paper analyses the heat loss change in four district heating distribution networks (DHNs) of Kaunas at the various scenarios of buildings and DHN renovation stages. A bundle of genetic algorithm software package was used to carry out the districts’ distribution network hydraulic calculations in the case of building renovation without changing the hydrodynamic and network routes. The experimental data were used to calculate heat loss for old and new pipes. The computer data of networks used to summarise the cost of DHN then for the renovation of buildings as well as for renovation progress will go evenly with DHN refurbishment. Network optimization results were summarised by functional dependence. The comparison of the projects’ efficiency was analysed in the following cases: the diameters of pipes of DHN were not changed, new diameters of pipes were integrated partly after partial residential buildings renovation and after a complete renovation of residential building and optimisation of pipeline diameters. The efficiency of separate guidelines of the DHN refurbishment project was summarised by performing sensitivity analysis

Operational performance of an Air Handling Unit: insights from a data analysis

Space heating and cooling is one of the most relevant causes of energy consumption in both residential and tertiary sector buildings. In particular, service buildings and offices are mostly served by all-air HVAC systems in which control logics are fundamental to guarantee reliability and performance. Building automation systems are therefore becoming more and more relevant as a support tool for reducing the energy consumption in these contexts. For this reason, the detailed analysis of operational data from real units can help in understanding the main variables that affect the performance and functioning of all-air systems. This paper presents some results from operation data analysis of an Air Handling Unit (AHU) serving a large university classroom. The main drivers of the energy consumption are highlighted, and the classroom occupancy is found to have a significant importance in the energy balance of the system. The availability of historical operation data allows performing a comparison between the actual operation of the AHU and the expected performance from nominal parameters. An example of fault detection is proposed, considering the operation analysis of the heat recovery unit over different years

Development of Envelope Evaluation Benchmarks Using EnergyPlus and Data-Driven Thermal Model

Residential buildings account for a large portion of the consumption of the global energy and total energy by end use. To mitigate the rising trend of energy consumption, residential buildings show a huge potential by improving their energy efficiencies, thus achieving energy saving. Moreover, the envelopes of the residential building, as one of key factors in the energy consumption of a building, are closely related to building energy saving, as it closely determines how much heat is transferred between indoor space of the building and its outdoor environment. Even though the challenges in how to judge the performance of the residential envelopes, especially evaluation of the overall building envelope via model-based data-driven and measurement-based methods, have been addressed by current studies and still have their limitations in comparison with ground truth, a method to benchmark the envelope performance evaluation is still lacking and urgently needed. Therefore, a benchmarking method using both building energy and thermal network models is proposed in this study. Specifically, this study first proposes a calibration method that utilizes both EnergyPlus and simplified 2R2C models. The EnergyPlus models are used to generate simulated data that are utilized in the simplified 2R2C model training. Moreover, this study also creates an excel dashboard, along with the the EnergyPlus and simplified 2R2C models, for the calibration process. Then three representative years of American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards are selected to the minimum thermal property requirement of residential building envelope and utilized in the calibrated EnergyPlus models. In the next step, a benchmarking method is proposed to determine the minimum required Tau value (time constant of building envelope) for a specific year of a residential building envelope. That is, different years of houses need to meet the minimum thermal property requirement of residential building envelope defined by ASHRAE standards. Lastly, the performance evaluation benchmarking process can be done with the determination of thermal properties identified by the simplified 2R2C model trained using simulated data from the calibrated EnergyPlus model. Overall, this research successfully proposes an efficient calibration method to calibrate EnergyPlus modes used for residential buildings, introduces quantitative study and performance analysis of a calibration method that utilizes building thermal network models, and develops a benchmark method and shows investigation and analysis for building envelope performance evaluation. Therefore, this research contributes the knowledge of benchmarking the envelope performance evaluation using both EnergyPlus and data-driven thermal model for residential buildings