Single-family Residential Building Research Articles

Renewable Energy Sources in the Processes of Thermal Modernization of Buildings—Selected Aspects in Poland

The article presents selected aspects of the energy modernization process of a single-family building, carried out in accordance with the legal regulations of Poland. One of the elements of this process is the use of renewable energy sources in the selection of heat sources. Two variants of thermo-modernization solutions for the tested facility were generated using the CERTO and the Aterm computer program. One was a heat pump, and the second was hybrid, in which the heat pump is supplied with electricity from photovoltaic panels. The key point of considerations was to conduct a comparative analysis of the operating costs of applied solutions. All variants were based on the same output data including the same building materials from which the thermal modernization process was carried out. The only difference was in the use of different types of thermal energy sources. The aim of the article was, therefore, to carry out a comparative analysis of variants of heat sources used in a single-family residential building—heating in a traditional way and through the use of photovoltaic panels and a heat pump. The results of the analysis in the context of benefits obtained from using renewable energy sources for heating residential buildings are discussed. The analysis showed that the simultaneous application of a heat pump and solar collectors in the analyzed building effectively influenced the values of indicators of annual demand for usable, primary, and final energy. The main conclusion of this research is that the amount of final energy demand in the analyzed case decreased from 86.04 kWh/(m2/year) with natural gas to 40.46 kWh/(m2/year) with a heat pump and a solar collector.

A hierarchical layout approach for underfloor heating systems in single-family residential buildings

The layout of an underfloor heating system determines its heating performance. Conventionally, the design is completed by qualified experts using professional software, but this method is inefficient and heavily relies on the experts’ previous experience. This paper proposes a hierarchical approach for the automatic design of underfloor heating systems aimed at residential buildings, and the underfloor heating layout problem is decomposed into a routing problem and coverage path planning problem. First, the routing problem is formulated as a shortest path problem in an appropriate routing graph and solved to provide the routing of pipes for further coverage. Subsequently, a depth-first layout algorithm is developed to recursively simplify the coverage path planning problem to obtain the basic rectangle layout, achieving uniform coverage of the given layout zone. Simulation results on two houses show that, unlike one popular commercial platform, the proposed approach generated feasible solutions in all 13 test instances. The new method improved the minimum temperature, average temperature, average percentage of nodes greater than 30 °C, and total energy efficiency by 3.18 °C, 0.79 °C, 3.23%, and 4.19%, respectively, with a lower variance on average. These improvements lead to a higher coverage rate, more even thermal distribution, and stronger robustness under flexible parameter selection.

Metamodel Development to Predict Thermal Loads for Single-family Residential Buildings

Metamodel Development to Predict Thermal Loads for Single-family Residential Buildings

Application of a Thermal Performance-Based Model to Prediction Energy Consumption for Heating of Single-Family Residential Buildings

Energy consumption for heating of single-family residential buildings is a basic item in energy balance and significantly affects their operating costs. Accuracy of heat consumption assessment in existing buildings to a large extent determines the decision on taking actions aimed at heat consumption rationalization, both at the level of a single building and at regional or national level. In the case of energy calculations for the existing buildings, a problem often arises in the form of lack of complete architectural and construction documentation of the analyzed objects. Therefore, there is a need to search for methods that will be suitable for rapid energy analysis in existing buildings. These methods should give satisfactory results in predicting energy consumption when there is limited access to data characterizing the building. Therefore, the aim of this study was to check the usefulness of a model based on thermal characteristics for estimating energy consumption for heating in single-family residential buildings. The research was conducted on a group of 84 buildings, for which the energy characteristics were determined based on the actual energy consumption. In addition, information was collected on variables describing these buildings in terms of construction technology and building geometry, from which the following were extracted for further calculations: cubic capacity, heated area, and year of construction. This made it possible to build a prediction model, which enables the application of a fast, relatively simple procedure of estimating the final energy demand index for heating buildings. The resulting calculations were compared with actual values (calculated from energy bills) and then evaluated according to the standards for evaluating model quality proposed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). In this way, it was possible to determine whether, in the absence of building documents, the indicative method gives good results when estimating the energy demand for heating single-family residential buildings.

An adaptive control framework based on Reinforcement learning to balance energy, comfort and hygiene in heat pump water heating systems

A major challenge in the operation of water heating systems lies in the highly stochastic nature of occupant behavior in hot water use, which varies over different buildings and can change over the time. However, the current operational strategies of water heating systems are detached from occupant behavior, and follow a conservative and energy intensive approach to ensure the availability of hot water any time it is demanded. This paper proposes a Reinforcement learning-based control framework which can learn and adapt to the occupant behavior of each specific building and make a balance between energy use, occupant comfort and water hygiene. The proposed framework is compared to the conventional approach using the real-world measurements of hot water use behavior in a single family residential building. Although the monitoring campaign has been executed during home lockdown due to COVID-19, when the occupants exhibited a very different schedule and water use related behavior, the proposed framework has learned the occupant behavior over a relatively short period of 8 weeks and provided 24.5% energy use reduction over the conventional approach, while preserving occupant comfort and water hygiene.

Structural bracing of wooden roofs under the extreme winds

An essential element of every building is a roof that protects it against the influence of weather conditions - rainfall, wind, and temperature changes. The shape of the roof, the type of roof covering, and the slope of the roof have the greatest impact on the type and material solutions. The roof structures are made of wooden, steel, or reinforced concrete. Especially in single-family residential buildings, wooden roof structures are most often used. Wood is perceived by many as the oldest and best building material, valued for its low weight, good strength, elasticity, and high thermal and insulation values. Traditional roof has been used over the centuries. The more common roof in wood framing roof is gable and hip roof which is consist of rafter, ridge, hip, collar tie and joist. The common slop for hip roof is 3/12 to 12/12. By increasing the slop, the length of the hip element in roof increases and needs to brace closely. The aim of the study is to analyse the location of roof braces in hip roof structures, due to the ultimate and serviceability limit states, under dead, live and wind loads based on finite element method model. Two wind speeds of 22 m/s and 40 m/s is taken into consideration. Elements with the different spans, cross-sections and slope of the roof are analysed.

The Methodology for Designing Residential Buildings with a Positive Energy Balance—Case Study

The article presents the results of the application of an original methodology for designing residential buildings with a positive energy balance in accordance with the principles of sustainable development. The methodology was verified using a computational example involving the selection of a compromise solution for a single-family residential building with a positive energy balance located in Warsaw, Poland. Three different models of decision-makers’ preferences were created, taking into account selected decision sub-criteria. Three technical solutions were identified, permissible according to the principles and guidelines for designing buildings with a positive energy balance. As a result of the performed calculations, the final order of the analyzed variants was obtained, from the most preferred to the least accepted solution. Variant 2 is definitely the most advantageous solution, being the best in a group of 20 to 26 evaluation sub-criteria—depending on the adopted model of the decision-maker’s preferences. Its ranking index Ri ranged from 0.773 to 0.764, while for the other variants it was much lower and varied from 0.258 to 0.268 for variant 1, and from 0.208 to 0.226 for variant 3. The methodology used for the case study proved to be applicable. The developed methodology facilitates the process of designing residential buildings with a positive energy balance, which is an extremely complex process.

Evaluation of phase change plaster/paste composites for building envelopes

Thermal energy storage (TES) materials increase a building’s thermal mass and provide the flexibility to shave and time-shift energy use. These materials are needed to enable grid-interactive efficient buildings, allowing building occupants to lower costs by leveraging free ambient heating/cooling as well as shifting consumption to cheaper electricity periods. Phase change materials (PCMs) that store heat through a solid–liquid/solid–solid transformation are of particular interest for TES because of their ability to store large amounts of energy across a constant temperature or very small temperature range. Previous studies on PCM building envelopes evaluated products that may only be incorporated as part of new construction and are not easily applicable to existing, energy-intensive buildings. In this work, we leverage laboratory PCM characterization and whole-building energy simulation to study the energy and cost savings of PCM plaster/paste coatings, which can be applied post construction to both new builds and retrofits of existing buildings (about 40% of residential buildings in the United States fall into the retrofit category). We evaluated the energy impact of PCM plaster/paste composites for a single-family residential building in the United States, including layer design (location and thickness), composite properties (phase change temperature, energy density, and shape of the enthalpy curve), and U.S. climate zone. The enthalpy curve shape of PCM shows that phase change temperature and energy density are not the only two parameters that must be considered for PCM selection. Maximizing the energy density amid the effective TES zone is key to boosting energy savings. We also studied PCM price targets with the aim of achieving reasonable payback periods based on both block and time-of-use electricity rates. Moreover, we developed an empirical equation to provide a rough estimate of the energy savings potential of incorporating PCM without the need to perform detailed simulations. These results will help guide the selection and design of PCM plaster/paste composite elements for residential building envelopes.

Tightness of Single-Family Buildings Made in Prefabricated Wood Frame Technology

The overall objective of the study is to determine the influence of various factors on the tightness of frame-based buildings. The study presents airtightness tests—Blow Doors Tests of single-family residential buildings made in the prefabricated wood frame technology. Primarily, the impact of selected quantitative and qualitative parameters on the determined quantity n50 was defined. For that purpose, correlation analyses were performed and the statistical hypothesis stating that there is no statistically significant linear relationship between n50 (a multiplication factor of air exchange in the building effected by pressure difference of 50 Pa) and the specified qualitative and quantitative parameters was verified. The hypothesis was verified using the F and χ2 statistics. The studies demonstrated that there are no grounds to reject the research hypothesis. The obtained results formulate a comprehensive conclusion that allows to test the tightness of buildings made in the prefabricated wood frame technology and makes the tightness results independent of many features of the examined building. Ultimately, the tightness results are only dependent on the leak of the examined object. They do not depend on roof structure, wall system, floor area, cubature, number of window openings, porch.

The Significance of Architectural Styles in Glapsides Residential Settlement

his broad understanding of style as a social and study of distinctiveness has some precedents in sociology, architecture, language, art and many other works which provide a framework that accommodates theories among other semiotic forms. Architectural style is a by-product of the understanding of artifacts that distinguish products or period in to distinct, and consequently, people perceived it as a unique or popular tendency. Glapsides contemporary individual-built area in Famagusta district is characterized by outstanding appearance of architectural styles in a contextual manner within the post-modern cycles. The representation of the diverse architectural styles creates an avenue for reach post-modern settlement that even the environmental values, history and a culture can be read easily. Thus, contemporary residential buildings with stylistic architectural appearances displayed some qualities of classical models as well contained traditional heritage. This research aimed at discussing the significances of architectural styles in contemporary residential buildings of Glapsides in Famagusta district. The paper focused its scopes on single-family residential buildings, with regard to the physical categories of their architectural fashions (façade). It will further explore the general contributions of architectural styles as means of creating contextual continuity, from the neighborhood to the district as a whole. In this research, the significance of architectural style will be evaluated based on their historic references, aesthetics and design characteristics as well as the visual contextual manners in the categories. In order to succeed and achieve this aim, twelve (12) case studies was selected within Glapsides area (region) and it was divided categorically based on their architectural styles. However, based on the selected cases a personal observation, effective site survey studies, and related literatures are the techniques adapted to source supportive data. The paper focused on the physical appearances only, plan scheme and measurement of component will not be discussed.

Life Cycle Assessment of the Use of Phase Change Material in an Evacuated Solar Tube Collector

This paper presents an environmental impact assessment of the entire cycle of existence of the tube-vacuum solar collector prototype. The innovativeness of the solution involved using a phase change material as a heat-storing material, which was placed inside the collector’s tubes-vacuum. The PCM used in this study was paraffin. The system boundaries contained three phases: production, operation (use phase), and disposal. An ecological life cycle assessment was carried out using the SimaPro software. To compare the environmental impact of heat storage, the amount of heat generated for 15 years, starting from the beginning of a solar installation for preparing domestic hot water for a single-family residential building, was considered the functional unit. Assuming comparable production methods for individual elements of the ETC and waste management scenarios, the reduction in harmful effects on the environment by introducing a PCM that stores heat inside the ETC ranges from 17 to 24%. The performed analyses have also shown that the method itself of manufacturing the materials used for the construction of the solar collector and the choice of the scenario of the disposal of waste during decommissioning the solar collector all play an important role in its environmental assessment. With an increase in the application of the advanced technologies of materials manufacturing and an increase in the amount of waste subjected to recycling, the degree of the solar collector’s environmental impact decreased by 82% compared to its standard manufacture and disposal.

Strategy for achieving long-term energy efficiency of European single-family buildings through passive climate adaptation

The presented study aims to clarify the implications of passive design measures on heating and cooling energy use of single-family residential buildings under European representative climates. In order to address this matter, different values of thermal transmittance (opaque and transparent), window to floor ratio, window distribution, shape factor, diurnal heat storage capacity, external opaque surface solar absorptivity and natural ventilation cooling rates were combined in 496,800 building energy models, which were simulated at eight locations. Because buildings are in use for many decades, the energy use simulations were made considering the projected climate change up to the end of the 21st century. The results delivered a set of the most effective passive design measures for achieving low energy use in buildings regarding climate type and period. A lower window to floor ratio was identified as the most universally applicable design measure to counterbalance the projected effect of a warming climate. In contrast, other measures vary according to climate type and studied period. Furthermore, it was concluded that it is difficult to neutralise the projected climate change effects on buildings' energy use, even when applying the best performing combination of passive design measures. However, reasonably low energy use can still be assured solely by passive building design, especially in oceanic, warm, and some temperate climate locations. Therefore, the identified trends in energy use and passive design measures represent the foundation for strategies and guidelines aimed at future-proof energy-efficient buildings.

Analyses of the Life Cycles and Social Costs of CO2 Emissions of Single-Family Residential Buildings: A Case Study in Poland

Comprehensive environmental impact assessments of buildings and construction as a whole consider the preparation of construction and finishing materials, their transportation, the process of erecting buildings, long-term operations—including the consumption of electricity, water, and fuels—and the management of the waste generated during the demolition of facilities. In terms of the above-mentioned elements, the most negative environmental impact on a building’s life cycle is in its exploitation stage. In order to reduce this impact, modern sustainable construction uses renewable energy sources. In the area of the Polish building market, analyses of CO2 emissions, the application of LCAs for building materials, and assessments of the social impacts of modern buildings are still very limited. The aim of this study is to evaluate the environmental life cycles and social costs of the CO2 emissions of single-family residential buildings, in which four different systems providing energy (heat and electricity) from renewable and nonrenewable sources are used. In this research, it was found that the annual CO2 emissions per square meter of building surface area in the analyzed objects were in the range of 30 to 176 kg CO2. The greatest contributor to the environmental effects was energy consumption (58% to 90%). The CO2 analysis conducted showed that facilities that use a heat pump are characterized by an environmental effect that is six times lower than that of facilities that are powered by coal combustion and electricity from the network. Similarly, the social costs associated with CO2 emissions were significantly lower in the case of the use of renewable energy sources.

Annual Evaluation of a Model Predictive Controller in an Integrated Thermal-Electrical Renewable Energy System Using Clustering Technique

Abstract Whitebox model in a model predictive controller (MPC) for energy systems, though does help in developing an accurate system model, requires a long time for optimization. In this article, an adaptation of the clustering technique used in hardware-in-the-loop testbench is proposed for evaluation of the MPC on an annual scale with selected six representative days in a year for that particular system and location. Initially, the various input parameters for clustering (algorithm, distance metric, and datapoint input dimensions) are studied for the selected thermal-electrical integrated renewable energy system (with solar thermal collectors, auxiliary gas boiler, stratified thermal storage, micro fuel cell combined heat and power (FC-CHP), photovoltaic system, a lithium-ion battery) for a Sonnenhaus standard single-family residential building. Finally, the proposed methodology is used to compare the annual derived energy values and key performance indicators (KPIs) for an MPC implementation with a status quo controller as a reference. Also, extreme exemplary weather days are investigated as the selected representative days were only average days in each season. Despite the conflict of using the FC-CHP on cold sunny days, instead of utilizing the battery and increased gas boiler energy input, a 9% increase in decentral system fraction is reported. Via the use of MPC instead of status quo controllers, the results indicate −18% space heating (SH) demand; +30% solar thermal energy production; −29% gas boiler energy supply; −52% power-to-heat thermal energy supply; −52% electrical fuel cell production; +240 kWh battery utilization; and −52% reduced grid import at the expense of 1.2% of the electrical load demand as grid import.

Análise técnico-econômica de fundação superficial tipo radier para uma residência unifamiliar

A fundação é um dos elementos estruturais mais importantes para uma edificação, ela é responsável por transferir para uma camada resistente do solo, todas cargas da edificação. As fundações podem ser divididas entre superficiais e profundas. O radier é um tipo de fundação superficial que se trata de uma laje de concreto que distribui uniformemente as cargas da edificação para o terreno. O objetivo deste artigo é, através de um estudo de caso de uma edificação residencial unifamiliar, comparar técnicas construtivas da fundação tipo radier, em relação à sapata isolada, por meio de uma análise técnico‑econômica entre os dois tipos de fundações superficiais, a fim de definir aquele que apresenta melhor viabilidade construtiva. Para isso, foi utilizado um projeto já dimensionado em sapatas, e, com os mesmos dados, realizou-se um dimensionamento estrutural do radier pelo software Eberick. Mediante aos resultados, foram elaboradas planilhas orçamentárias com valores de referências baseados na tabela regional da SINAPI e cronogramas físicos. Para isso, considerou-se a mesma equipe e jornada de trabalho para ambos os métodos. De acordo com os resultados obtidos, em relação ao custo e prazo, a sapata é mais onerosa e morosa que o radier. Sendo assim, conclui-se um excelente desempenho do radier em relação à sapata, pois quando bem dimensionado, poderá proporcionar melhor viabilidade técnico-econômica para a fundação, que é um dos elementos estruturais mais importantes do edifício. Ressalta-se que esta análise está restrita a este estudo de caso, porém, os resultados obtidos são corroborados por outras literaturas.

A method for determining the financial cost of damage to buildings caused by seismic ground vibrations

A method for determining the value of the damage to a single-family residential building located near an open-pit mine caused by ground vibrations is presented. The article describes how to objectively determine the degree of actual wear and tear to a residential building (Zr) affected by ground vibrations created during rock mining using blasting. It consists of the method of "weighted average degree of technical wear and tear of individual elements" known from literature and used to calculate the actual wear and tear of the building. The natural wear and tear of the building is then calculated from dependences given in the literature. The percentage of the building’s natural wear and tear (Zn) is subtracted from the percentage of the building’s actual wear and tear. As a result of the subtraction, a percentage of accelerated wear and tear of the building (Zb), which is caused by vibrations of the ground during rock blasting, is obtained. Multiplying the percentage of accelerated wear and tear of the building by the value of a new building gives a value of the damage caused by ground vibrations. Examples of determining the value of the damage caused by ground vibrations in practice are described.

ІСТОРИЧНІ ПЕРЕДУМОВИ ФОРМУВАННЯ ВИСОКОЩІЛЬНОЇ МАЛОПОВЕРХОВОЇ ЖИТЛОВОЇ ЗАБУДОВИ

The article discusses key issues related to the historical prerequisites for the formation of a high-density low-rise residential development. This is a complex and long process, the stages of which took place at different times and in different countries of the world. Today, such a building is very promising for modern rapidly growing cities, so it is important to track the history of its formation and the features of such planning decisions at different times. Such architecture can become a new vector in the development of modern cities, because low-rise residential buildings are much more comfortable than high-rise buildings. The article gives examples of low-rise city houses in different histories and in different countries. The aim of this work is to review the historical background of the formation of modern high-density low-rise buildings. The following historical examples of low-rise high-density buildings are considered: early single-family residential buildings of the ancient settlements of Mesopotamia and Egypt, residential buildings in Ancient Greece and Rome, blocked residential buildings for workers in the 19th century. In the UK, townhouses of the 1920s and 30s. In the USA, etc. The article shows the planning decisions and the appearance of low-rise high-density residential buildings. The main features of such houses are quarterly development, large-scale man, blocked development and the presence of a small house area.

How much HVAC energy could be saved from the occupant-centric smart home thermostat: A nationwide simulation study

Thermostat management plays a significant role in household energy conservation. This study aims to conduct a systematic and comprehensive analysis to quantify the energy savings potential of the occupant-centric smart thermostat based on a large-scale nationwide simulation infrastructure. The single-family Residential Prototype Building Model was used to represent a typical single-family detached house in the U.S. A generalized random occupancy presence schedule was created based on an occupancy probability schedule and k-means clustering algorithm. A total of 16,000 simulations, which were composed of four building foundation types, four heating source types, 40 American cities, five building energy code versions, and five thermostat control strategies, were conducted to evaluate the performances of the smart home thermostat in terms of saving building energy usage and maintaining occupant thermal comfort. The nationwide simulation results suggested that the temperature setback control during the unoccupied period could achieve some energy savings in the U.S. households. However, only very few of the 40 cities could see an annual Heating, Ventilation, and Air-conditioning energy savings ratio of over 30%. Besides, the implementation of the occupied standby temperature reset could greatly increase the peak load of the HVAC system and contribute to the grid load imbalance issue. It’s also worth noting that the smart recovery feature is proved to be able to bring additional benefits for a smart home thermostat. It could decrease the temperature setpoint not met time by about 30 min, and relieve the thermal discomfort due to the temperature setback control.

User-friendly rolling control strategy for a heat pump heating system considering building thermal inertia

A user-friendly rolling control strategy for a heat pump heating system (HPS) considering building thermal inertia is proposed. A model of a typical HPS is established to reflect the thermal dynamic processes in different HPS parts. A model of the building heat load is also developed considering the actual heat transfer processes related to the building. Based on this, a control strategy framework for the HPS is proposed considering building thermal inertia and temperature comfort level. The optimal temperature set-point of the HPS in each control horizon is determined by the strategy through rolling control. A case study of a single-family residential building on a typical winter day in northern China demonstrates the benefit of the proposed strategy in terms of reducing the operating cost without disturbing the temperature comfort level. The impacts of the penalty factor regarding deviation from the user-expected indoor temperature and of the building envelope are further analysed and compared.

Footprints of failure: Quantifying carbon impacts of roof leakages in a single-family residential building

To meet the UN Sustainable Development Goals of climate change mitigation and sustainable cities, low-carbon or carbon-negative buildings are becoming increasingly common. The buildings are planned to compensate for the embodied energy in their materials by using low-emission materials and generating emission-free energy. Embodied energy is minimized while energy generation is maximized. However, embodied energy calculations seldom consider the risk of building defects that require repairs or early replacement of building elements. As such, a building’s sustainability is often calculated under the assumption that significant defects do not happen, which is known to rarely be the case. In this article, the material and monetary costs of repairing building defects are analysed. Findings suggest that certain building defects, like major roof leaks, have a significant carbon footprint. A large portion of this footprint can be attributed to the drying of the building after a leak is discovered. Building defects are common enough that the risk should not be neglected in life cycle analyses. Likewise, measures taken to reduce the risk of building defects, such as avoiding design solutions known to pose difficulties, may be considered as means to improve the sustainability of a building as well as reducing economic costs.