scholarly journals Predicting energy demand of residential buildings: A linear regression-based approach for a small sample size

2021 ◽  
Vol 16 (2) ◽  
pp. 67-85
Author(s):  
Soufiane Boukarta

Abstract The key design strategies that reduce the energy demand of buildings are not present in most thermal codes in many countries. Therefore, modeling techniques offer an alternative to combine the architects' modus operandi with the energy efficiency in the early stages of architectural design and with higher speed and precision. However, a review of the scientific literature using modeling techniques shows that most researchers use a relatively large sample of thermal simulations. This paper proposes a simplified method based on the linear regression modeling technique and considers a relatively smaller sample of thermal simulations. A total of 6 key building design strategies were identified, related to the urban context, building envelope, and shape factor. A simulation protocol containing 60 possible combinations was designed by random selection. In the present study, the Pleiades software was used to estimate the annual energy demand for heating and cooling for a typical dwelling in a humid climate zone. A parametric study and sensitivity analysis to identify the most efficient parameters was performed in SPSS 21. The resulting model predicts the annual energy demand with an accuracy of 93.7%, a root mean square error (RMSE) of 5.88, and a scatter index (SI) of 8.59%. The models performed could efficiently and quickly assist architects while designing the buildings in the architectural practice.

2020 ◽  
Vol 172 ◽  
pp. 02009
Author(s):  
André Badura ◽  
Birgit Mueller ◽  
Ivo Martinac

Large and rapid climatic changes can be uncomfortable and sometimes hazardous to humans. Buildings protect people from external climatic conditions, and also mitigate the impacts of external climate extremes through their design and construction, as well as with the help of dedicated building service and other technical systems. Active space conditioning accounts for more than 30 per cent of the overall final energy use in Germany. In the life cycle of a building, the construction phase (planning and construction) is the phase with the shortest duration. However, the quality applied during this phase has a significant impact on the resources required, as well as the overall building performance during the much longer operational phase. Once built, buildings are often unable to adapt to boundary conditions that were not considered in the original building design. Consequently, changing outdoor climate conditions can result in an uncomfortable indoor climate over the lifetime of a building. The aim of this study was to determine the effectiveness of flexible solutions for reducing winter heating loads and to reducing/avoiding summer cooling loads in nonresidential buildings in Germany. Various external shading scenarios for non-residential buildings were analysed using the IDA ICE indoor climate and energy simulation tool. Key simulation parameters included the orientation and location of the building, as well as the envelope structure. We investigated the impacts of solar shading on heat storage in the building mass and indoor climate and how different types of envelopes affect overall energy use. The result shows that the use of an adaptive building envelope allows a higher reduction of the total energy demand by 7 % to 15 % compared to an increase in insulation thickness only.


2021 ◽  
Vol 14 (1) ◽  
pp. 65
Author(s):  
Muhammad Usman ◽  
Georg Frey

The comprehensive approach for a building envelope design involves building performance simulations, which are time-consuming and require knowledge of complicated processes. In addition, climate variation makes the selection of these parameters more complex. The paper aims to establish guidelines for determining a single-family household’s unique optimal passive design in various climate zones worldwide. For this purpose, a bi-objective optimization is performed for twenty-four locations in twenty climates by coupling TRNSYS and a non-dominated sorting genetic algorithm (NSGA-III) using the Python program. The optimization process generates Pareto fronts of thermal load and investment cost to identify the optimum design options for the insulation level of the envelope, window aperture for passive cooling, window-to-wall ratio (WWR), shading fraction, radiation-based shading control, and building orientation. The goal is to find a feasible trade-off between thermal energy demand and the cost of thermal insulation. This is achieved using multi-criteria decision making (MCDM) through criteria importance using intercriteria correlation (CRITIC) and the technique for order preference by similarity to ideal solution (TOPSIS). The results demonstrate that an optimal envelope design remarkably improves the thermal load compared to the base case of previous envelope design practices. However, the weather conditions strongly influence the design parameters. The research findings set a benchmark for energy-efficient household envelopes in the investigated climates. The optimal solution sets also provide a criterion for selecting the ranges of envelope design parameters according to the space heating and cooling demands of the climate zone.


2018 ◽  
Vol 39 (2) ◽  
pp. 135-146 ◽  
Author(s):  
David Jenkins

The low-carbon building design process for a building engineer is often confined to construction, building services and occupancy. However, as we see coincident changes in climate, technologies, fuels and operation, it becomes important to extend this understanding to include wider energy systems, while clarifying the importance of the built environment within that system. With energy systems, such as the National Grid, involving multiple actors from different disciplines, a key challenge is to provide guidance and future projections that are translated into different discipline-specific vernaculars, but with a genesis of common assumptions. More generally, integration across the disciplines must be reflected by modelling approaches, policy-making frameworks and outputs. This article will demonstrate the initial stages of the energy demand research of the Centre of Energy Systems Integration project, where novel modelling techniques are being used to explore the effect of future buildings on national energy systems. Practical application: The tools and techniques described within this article are designed with future industry practice in mind. The driver is the increased importance of external factors outside the traditional building envelope in determining the energy and carbon performance of a building (or buildings). Building engineers, and others within building design teams, require a new portfolio of tools and resources to better account for the impact of buildings on wider energy systems and vice versa. The role of such practitioners is therefore likely to evolve.


Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 642
Author(s):  
Mark Kyeredey Ansah ◽  
Xi Chen ◽  
Hongxing Yang

Reducing the lifecycle energy use of buildings with renewable energy applications has become critical given the urgent need to decarbonize the building sector. Multi-objective optimizations have been widely applied to reduce the operational energy use of buildings, but limited studies concern the embodied or whole lifecycle energy use. Consequently, there are issues such as sub-optimal design solutions and unclear correlation between embodied and operational energy in the current building energy assessment. To address these gaps, this study integrates a multi-objective optimization method with building energy simulation and lifecycle assessment (LCA) to explore the optimal configuration of different building envelopes from a lifecycle perspective. Major contributions of the study include the integrated optimization which reflects the dynamics of the whole lifecycle energy use. Insights from the study reveal the optimal configuration of PV and composite building façades for different regions in sub-Saharan Africa. The lifecycle energy use for the optimized building design resulted in 24.59, 33.33, and 36.93% energy savings in Ghana, Burkina Faso, and Nigeria, respectively. Additionally, PV power generation can efficiently cover over 90% of the total building energy demand. This study provides valuable insights for building designers in sub-Saharan Africa and similar areas that minimize lifecycle energy demand.


2018 ◽  
Vol 57 ◽  
pp. 04001 ◽  
Author(s):  
Albert Al Touma ◽  
Djamel Ouahrani

Al-Majlis is the living space in residential buildings of the Arabian Gulf, and is where occupants spend most of their time. For this reason, the human thermal comfort in this space is of extreme importance and is often compromised due to hot outdoor weather conditions. In contrast with many thermal discomfort mitigation methods in outdoor environments, which become unadvisable in indoor spaces, this study investigates the effect of adding PCM-enhanced tiles to portions of the indoor envelope on the occupant’s thermal comfort and the space cooling energy demand. A simulation model of a space with tight building envelope in Qatar was developed on EnergyPlus with and without the addition of PCM-enhanced tiles. The selected country is a representative location of the Arabian Gulf. Considering different occupant’s positions, the addition of the tiles with PCM on their back was found to moderate the mean radiant temperature, operative temperature, Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD), all of which signify an improvement in the human thermal comfort. Lastly, this change in the indoor envelope was found to save 3.3% of the space daily thermal cooling energy demand during one harsh summer representative day.


2020 ◽  
Vol 12 (2) ◽  
pp. 691 ◽  
Author(s):  
Rui Han ◽  
Daping Liu

The objective of this study was to understand the development of Chinese contemporary architectural discourses and analyze the comfort of the 156 projects residences to help improve the sustainable planning and design of today’s urban residential buildings. With a literature review, we described the formation and evolution process of the Soviet Union socialist realism architectural discourses that initially and deeply influenced urban residence in Northeast China and revealed the input channel and localization process of Chinese socialist realism in residential projects. Through field measurement and investigation into the building design and construction from four aspects—building group planning, unit schema standardization design, facade aesthetics, and structural design—we comparatively analyzed results that indicated the design and construction in that era. The thermal environment was also simulated using analytical software to comprehensively evaluate heat loss and heat accumulation in the cases. Finally, three passive design strategies were discussed to improve the sustainability of residence in Northeast China.


Author(s):  
Robert Staiger

The chapter deals with the green energetic consideration of today's building envelopes for residential and non-residential buildings. It investigates the energetic effects the envelopes have on energy efficiency, energy consumption, material use, sustainable use of resources, lifetime considerations, economic and ecological impact. Today's it is estimated that approximately 30% of the annual primary energy demand for residential and non-residential buildings is needed. Energy resources for heat, electricity, air conditioning and cooling purposes, fossil fuels in form of gas and liquid are predominantly used.


2018 ◽  
Vol 44 ◽  
pp. 00069 ◽  
Author(s):  
Maciej Knapik

The article presents the problem of thermo-modernization and the reduction of energy demand for heating purposes in existing residential buildings. The thermo-modernization process has to adapt the existing building to the standard of a building with low energy demand and applicable regulations. Low-energy constructions are a result of introduction of new solutions in building design process. Their main objective is to achieve a significant reduction in demand for renewable primary energy, necessary to cover the needs of these buildings, mostly related to their heating, ventilation and domestic hot water. The article presents the results of the analysis and calculation of selected thermo-modernization variants. The results showed that thermo-modernization process of existing residential buildings is justified both energetically and economically.


2019 ◽  
Vol 112 ◽  
pp. 01016 ◽  
Author(s):  
Martin Ivanov

The “thermal bridges” are defined as an isolated building’s areas, where the construction elements have higher thermal conductivity, compared with the rest of the building envelope. Thus, at cold winter conditions, a significant temperature difference may occur between neighbouring solid and air volumes within the construction. Moreover, it has been documented, that the heating energy demand of a building may be increased with more than 30%, due to the existence of thermal bridges and the increased heat losses from the indoors. Consequently, in the recent years, norms and standards have been developed, for avoiding thermal bridges during the building design process. But still, thermal bridges exist in the indoor environment, especially in older buildings, where no energy efficient measures have been applied. That is why, the presented study focuses on instantaneous field measurements of thermal bridge parameters in real existing ground floor residential room. The thermal bridge propagation is analysed relative to the indoor and outdoor air temperature and relative humidity, as well as with infrared thermal images of the affected external walls. The achieved results give valuable information about the generic conditions for thermal bridge existence, without considering the building envelope properties.


Author(s):  
C. León-Sánchez ◽  
D. Giannelli ◽  
G. Agugiaro ◽  
J. Stoter

Abstract. The 3D BAG v. 2.0 dataset has been recently released: it is a country-wide dataset containing all buildings in the Netherlands, modelled in multiple LoDs (LoD1.2, LoD1.3 and LoD2.2). In particular, the LoD2.2 allows differentiating between different thematic surfaces composing the building envelope. This paper describes the first steps to test and use the 3D BAG 2.0 to perform energy simulations and characterise the energy performance of the building stock. Two well-known energy simulation software packages have been tested: SimStadt and CitySim Pro. Particular care has been paid to generate a suitable, valid CityGML test dataset, located in the municipality of Rijssen-Holten in the central-eastern part of the Netherlands, that has been then used to test the energy simulation tools. Results from the simulation tools have been then stored into the 3D City Database, additionally extended to deal with the CityGML Energy ADE. The whole workflow has been checked in order to guarantee a lossless dataflow.The paper reports on the proposed workflow, the issues encountered, some solutions implemented, and what the next steps will be.


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