Thermal Comfort In Residential Buildings Research Articles

Multi-objective optimization of residential building energy consumption, daylighting, and thermal comfort based on BO-XGBoost-NSGA-II

The energy consumption, daylighting, and thermal comfort of buildings directly affect the three key goals of residents. However, there is little research on the optimization of energy consumption, daylighting, and thermal comfort in residential buildings in China. Therefore, this study proposes an optimization framework that combines Bayesian optimization with extreme gradient boosting trees (BO-XGBoost) and non-dominated genetic algorithm-II (NSGA-II) to study the multi-objective optimization of residential building performance. This paper first uses Grasshopper to simulate and obtain a dataset through Latin hypercube sampling (LHS). BO-XGBoost is used to establish the regression relationship between building envelope design parameters and residential building performance. Then, the obtained regression model is used as the fitness function of NSGA-II to get the Pareto optimal solution set. Finally, the ideal point method is used to obtain the optimal combination of building envelope structure parameters for residential buildings. Taking a residential building in a hot summer and cold winter area as an example, the effectiveness of this method is verified. The results show that (1) BO-XGBoost has excellent predictive performance, with R2 values of 0.997, 0.960, and 0.994 for energy consumption, thermal comfort, and daylighting, respectively. (2) The proposed BO-XGBoost-NSGA-II can effectively achieve multi-objective optimization. Compared with the initial scheme of the case building, energy consumption is reduced by 44.1%, thermal comfort index is reduced by 10.9%, and daylighting performance is improved by 1.7%. Therefore, the proposed method can effectively optimize the performance goals of residential buildings and provide practical ideas for similar problems.

Evaluation of the Effectiveness of Passive Design Strategies in Achieving Thermal Comfort in Residential Buildings in Egypt

This study aims at thermal comfort improvement in residential buildings through utilization of passive design strategies and energy efficiency measures. The study investigates the impact of passive strategies on thermal comfort in hot dry climate of Egypt. A climatic analysis of three cities: Aswan, Cairo and Alexandria was conducted to examine passive design strategies’ efficacy. Thermal comfort in a residential building was examined by DesignBuilder simulation software. Annual simulations were performed on the model where several passive design strategies were applied. Passive design strategies’ potential was quantified and a parametric analysis was conducted for thermal comfort improvement. The results demonstrate that applying passive design strategies can be effective in reducing discomfort hours in hot climate. Comfort hours could be increased from 22.6% to 33.1 % in Aswan, while in Cairo can be increased from 31.1% to 38.6 %, and in Alexandria from 36.9% to 46 %. The research findings could be used by architects for thermal comfort improvement in residential buildings.

TRANSFORMATION OF PASSIVE DESIGN ELEMENTS FOR ACHIEVING THERMAL COMFORT IN RESIDENTIAL BUILDINGS OF MANSEHRA CITY, PAKISTAN FROM 1990 TO 2019

Among the most evolving issues in recent years, there is growing concern over global warming throughout the world. The construction industry has been considered among the major contributors to global warming. The use of building envelope along with the heating, cooling, and lighting design, operations, and infrastructures are the prime factors of this contribution. Due to this reason, the thermal comfort of buildings has become a major concern in building design globally. The following research explored the building design elements used for thermal comfort in residential buildings of Mansehra City of Khyber Pakhtunkhwa province in Pakistan and analyzed its transformation during the last three decades. The study proceeded by documenting and comparing various design elements to understand their transformation within documented time periods i.e. thermal mass, fixed shading devices, and the ratio of open and closed spaces. These elements were evaluated for their effectiveness in providing thermal comfort. It was concluded that these design elements have been adapted and modified with time with little concern for sustainability. It was found that the focus has shifted from building orientation, sun path, and wind directions to aesthetically pleasing forms only which makes them saleable and lack human comfort. The use of passive means to achieve thermal comfort was neglected. The research concludes by suggesting incorporation of appropriate thermal comfort components and methods into effective solutions for improved building designs, lower energy demand, and a better indoor atmosphere. Keywords: Thermal Comfort, Passive Design, Residential Building, Mansehra City, Global Warming

Learning from Vernacular and Integrating Retrofitting Techniques to Enhance Thermal Comfort in Residential Buildings: Insights from Tiruchirapalli, India

Learning from Vernacular and Integrating Retrofitting Techniques to Enhance Thermal Comfort in Residential Buildings: Insights from Tiruchirapalli, India

Effect of Natural Ventilation on Thermal Performance of Different Residential Building Forms in the Hot-dry Climate of Jordan

This work presents a simulation study on the impact of natural ventilation on the thermal performance and thermal comfort of residential buildings of different forms in the hot-dry climate of Amman, the capital of Jordan. Three existing triple-storey residential buildings with different forms, i.e., rectangular, L-shape, and U-shape, are taken as case studies. Models with similar construction and dimensions of the buildings under investigation are designed using the OpenStudio plugin SketchUp software. Two rooms within these buildings have been considered for simulation with the aid of the EnergyPlus simulator for two cases: the basic case with no ventilation and the case with ventilation. The thermal parameters, including the air temperature, relative humidity, air speed, and mean radiant temperature of both rooms, have been extracted from the simulation. The thermal performance of these buildings is analyzed based on the indoor air temperature and mean radiant temperature, while the thermal performance is investigated via the ASHRAE-55 adaptive model. The results show that the rectangular-shaped building has the best thermal performance in unventilated conditions for the middle room on the middle floor (Room 1). In contrast, the U-shape shows better results for the west-northern room on the same floor (Room 2). On the other hand, introducing natural ventilation to the buildings reduces the indoor temperature and, subsequently, enhances the thermal performance where the buildings transform to be within the comfort zone most of the time, according to the ASHRAE-55 adaptive model. Generally, rectangular and U-shaped buildings show comparable thermal performance, while L-shaped buildings have relatively the worst performance.

Decarbonising building heating and cooling: Designing a novel, inter-seasonal latent heat storage system

The global heating and cooling demands have increased to mitigate the effects of the rise in extreme weather events due to climate change. This has led to an increase in global greenhouse gas emissions due to the use of fossil fuels to meet these demands. The current study evaluates how an alternative low-carbon heating and cooling system may provide thermal comfort in residential buildings, specifically in regions that have a humid temperature oceanic climate-for example, the United Kingdom. To meet the net-zero emissions targets set in the United Kingdom by 2050, greenhouse gas emissions generated from heating in residential buildings must fall by 95 %. The leading decarbonisation strategy proposed by their government requires the electrification of the heating system through the installation of heat pumps. Consequently, the average electricity consumption per household is expected to increase. This will impose considerable pressure on electricity networks to source additional (ideally renewable) capacity, which will ultimately be costly. To circumvent this issue, the current study proposes a novel alternative method of providing nearly zero-carbon space and water heating, that can operate almost independently of the electricity grid. This requires the use of solar energy as the thermal energy source, and a solid-liquid phase change material as an inter-seasonal energy storage medium. A design optimisation study was thereafter carried forward to showcase the capability of such a system for a semi-detached house in London, United Kingdom.

An Integrated Decision-Making Framework for Mitigating the Impact of Urban Heat Islands on Energy Consumption and Thermal Comfort of Residential Buildings

Urban heat island (UHI) is a zone that is significantly warmer than its surrounding rural zones as a result of human activities and rapid and dense urbanization. Excessive air temperature due to the UHI phenomenon affects the energy performance of buildings and human health and contributes to global warming. Knowing that most of the building energy is consumed by residential buildings, therefore, developing a framework to mitigate the impact of the UHI on residential building energy performance is vital. This study develops an integrated framework that combines hybrid micro-climate and building energy performance simulations and multi-criteria decision-making techniques. As a case study, an urban area is analyzed under the Urban GreenUP project funded by the European Union’s Horizon 2020 Programme. Four different strategies to mitigate the UHI effect, including the current situation, changing the low-albedo materials with high-albedo ones, nature-based solutions, and changing building façade materials, are investigated with a micro-climatic simulation tool. Then, the output of the strategies, which is potential air temperature, is used in a dynamic building energy simulation software to obtain energy consumption and thermal comfort data of the residential buildings in the case area. Finally, a multi-criteria decision-making model, using real-life criteria, such as total energy consumption, thermal comfort, capital cost, lifetime and installation flexibility, is used to make a decision for decreasing the UHI effect on residential energy performance of buildings. The results showed that applying NBSs, such as green roofs and changing existing trees with high leaf area density ones, have the highest ranking among all mitigation strategies. The output of this study may help urban planners, architects, and engineers in the decision-making processes during the design phase of urban planning.

Multi-Objective Analysis of Visual, Thermal, and Energy Performance in Coordination with the Outdoor Thermal Environment of Productive Façades of Residential Communities in Guangzhou, China

Population growth and urban expansion have led to increased demand for buildings. Optimizing the building façade design, using integrated photovoltaic (PV) shading and vertical farming (VF) can reduce building energy consumption while ensuring a partial food supply. However, the importance and prevalence of productive façades have not received significant attention. Furthermore, few studies have focused on the impact of productive façades on both indoor and outdoor environmental qualities. Therefore, this study aimed to explore the potential of integrating productive façades with residential façades in high-density cities. A typical community in Guangzhou, China was investigated. Thermal comfort, light comfort, electricity production, and crop yield were considered, and the optimal façade configuration was chosen from the established 146-model library. The integrated module can effectively improve the indoor lighting and thermal comfort of residential buildings. The module also mitigates the outdoor thermal environment to a certain extent, meeting 6.3–10.3% and 7.6–9.6% of the annual electricity and vegetable demands, respectively, in residential communities. This study can guide other densely populated cities with subtropical climates to advance the research and construction of productive façades, improving occupant comfort, reducing energy consumption, and mitigating food security and urban climate change issues.

Adaptive thermal comfort of residential buildings in the composite climatic region of India: a field study

ABSTRACT This paper presents the results of an adaptive thermal comfort field study conducted in the naturally ventilated residential buildings in the composite climate type of India over three main seasons i.e. monsoon, winter, and summer using ASHRAE’s class II field measurements protocols. 768 measurements were collated wherein subjective thermal comfort sensation, preference, and acceptance for indoor environment variables were thoroughly explored along with the adaptive actions of the users for four different times during a day. Correlation analysis helped decipher the relationship between subjective votes and thermal comfort evaluation parameters. Thermal environment acceptance during monsoon season and morning time was highest however the same was found lower during summers and afternoons. The middle age group had the lowest acceptance and well-acclimatized non-native participants had a good thermal acceptance. Education also affects thermal acceptance and it decreases with increasing education level. The comfort temperature and adaptive comfort equation were also studied and results were compared with national and international thermal comfort standards. This study predicted a wider thermal comfort range of 12.23–34.45°C and indicated revising TSI, the first thermal comfort index for Indian Subjects.

Investigating the Influence of Thermal Conductivity and Thermal Storage of Lightweight Concrete Panels on the Energy and Thermal Comfort in Residential Buildings

Phase change materials (PCM) are integrated into lightweight concrete (LWC) panels to increase their thermal mass. However, the integration of PCM into LWC also increases the thermal conductivity of the panels, which may have a negative impact. This study investigated the impact of thermal resistance and storage of LWC panels on thermal comfort and energy use in buildings. Six different LWC panels with varying levels of thermal conductivity and storage were developed using various combinations lightweight aggregates and PCM. The experimentally measured properties were used in building simulation software EnergyPlus V9.3 to calculate overheating and building energy consumption for each panel. The result showed that thermal mass influences severe discomfort hours more than thermal resistance. However, the level of influence depends on the position of the panels compared to the insulation layer. The presence of an insulation layer reduced the energy savings rate. The cooling energy consumption was more influenced by the thermal mass, whereas the heating was more influenced by the resistance of the wall. Overall, the LWC panel with the highest thermal mass was the best to reduce severe discomfort hours and energy consumption despite having the highest thermal conductivity. The outcome of this study can help to design an external building envelope with PCM panel as per user requirements, which could be to reduce overheating or cooling only, heating only, or both cooling and heating.

A Review of Thermal Comfort in Residential Buildings: Comfort Threads and Energy Saving Potential

Residential buildings instigate a vital role in creating a safe and comfortable indoor living environment. The phenomenon of overheating, an impact of climate change, can cause a negative effect on residents’ productiveness and heat-related illnesses and can even force high pressure on electricity generation by increasing the risk of power outages due to excessive peak cooling and heating requirements. Various issues on building thermal comfort are being evolved and discussed in review articles. However, there are few articles that review the current condition of adaptive thermal comfort studies and the potential for energy savings in residential buildings. Therefore, the aims for this paper are to: identify comfort temperature ranges in residential buildings, investigate the correlation of comfort temperature with indoor and outdoor temperatures with the aid of ‘comfort threads’, and clarify the effect of adaptive measures on residential energy saving potential. This study obtained a large variation of residential comfort temperatures, which mostly depend on the climate and operation modes of the building. ‘Comfort threads’ explains that people are adapting to a large variation of indoor and outdoor temperatures and the wide range of comfort temperature could provide significant energy savings in residential buildings. This review provides insight on and an overview of thermal comfort field studies in residential buildings.

Comparative study of indoor thermal environment and human thermal comfort in residential buildings among cities, towns, and rural areas in arid regions of China

Most thermal comfort studies classify towns as rural areas and compare them with cities, dismissing the unique thermal characteristics of towns. A comparative study on thermal comfort in cities, rural areas, and towns based on their original definitions is required. This study aims to determine the differences between indoor thermal environment and human thermal comfort in residential buildings in cities, towns, and rural areas. This four-month investigation was conducted in Bayannur City using a survey with 141 participants. The survey responses were combined with environmental measurements, and the data analysis showed that the participants’ clothing insulation was distributed over a wider range for towns (0.3–0.9 clo) and rural areas (0.9–1.5 clo) than for cities (0.3–0.6 clo). The acceptable operative temperature ranges of city, town, and rural area residents were 20.9–28.0, 17.7–23.3, and 15.1–21.6 ℃, respectively. Although the operative temperature of residential buildings in those areas differed by 5–10 °C, all participants expected a warmer indoor thermal environment. City residents who can adapt to varying conditions can restore thermal comfort more easily than town and rural area residents.

EFFECT OF WINDOWS CONFIGURATION IN WALL PANELS ON ROOM TEMPERATURE IN NATURALLY VENTILATED RESIDENTIAL BUILDINGS IN ASABA, NIGERIA

The type of windows configuration in residential building influences the amount of radiation that enters into the interior occupied spaces. The level of comfort or discomfort experienced within the buildings is thus hinged on the type of window configuration in the building facade. There are different window configurations in the study area, and the environmental designers or architects use any of the window type in spite to its implication on thermal comfort aspect of the building. Physical measurements and questionnaire were conducted in naturally ventilated residential buildings, to investigate the effect of window configuration in wall panels on room temperature in naturally ventilated residential buildings in Asaba, Nigeria. The effect of indoor room temperature on occupant thermal comfort was examined. Different window configurations commonly used in residential buildings in the study area are sliding, projected, casement, casement-with-vent, and louvre window. The results show that appropriate window configuration in wall panels can provide comfort level on room temperature. Recommendations were made to improve thermal comfort in residential buildings using window configuration with PMV value of 4.5 or less which are casement with vent, louvre and casement windows in naturally ventilated residential buildings.

Thermal comfort optimization through bioclimatic design in Mediterranean cities.

Background: Bioclimatic design is an approach based on local climate which improves thermal qualities and indoor comfort. Buildings follow this process to minimize negative effects on the environment. However, this approach is still not suitable in developed countries. This study aims to investigate Mediterranean local bioclimatic strategies' impact on thermal comfort efficiency in housing, by examining architectural elements and treatments. Methods: We adopted a descriptive, analytical, and comparative methodology, complemented with a software simulation, within a qualitative and quantitative approach. Investigation and methodological tools were based on technical information including plans, elevations, photos, and documentation. The approach consisted of multiple stages: a literature review interpreting the concept of bioclimatic design, as well as thermal comfort variables and common Mediterranean building features. Moreover, the paper showcases three examples of successful Mediterranean passive houses. Furthermore, the paper presents a case- studyhouse in Alex West, Alexandria, designed in the Mediterranean Revival style. Results: The results showed that the most influencing building features on thermal comfort were the low-pitched roofs and the top chimney, which achieved 12.6% and 5% improvement in the summer and 13% and 6.8% in winter, respectively. The pergola and porch elements barely had an effect when placed on the northern façade. However, on the southern façade, a positive contribution in the summer by 1.4% and 3.4% respectively were reported, but a slight negative impact in winter by 0.5% and 2% respectively. Conclusions : We examined the impact of common Mediterranean building features , and compared thermal comfort results between case-study houses. Features focusing on passive design for cooling rather than heating, allowing wind flow for maximized natural ventilation, using ventilated pitched roof spaces, using sun shading elements in the proper facades and angles, help passive thermal regulation. The study proposes recommendations for optimizing thermal comfort in residential buildings in Alexandria, Egypt.

Science mapping approach based review of thermal comfort studies in Indian residential buildings

PurposeScience mapping is an essential application of visualization technology widely used in safety, construction management and environmental science. The purpose of this study was to explore thermal comfort in residential buildings (TCinRB) research in India, identify research trends using a science mapping approach and provide a perspective for recommending future research in TCinRB.Design/methodology/approachThis study used the VOSviewer tool to conduct a systematic analysis of the development trend in TCinRB studies in India based on Scopus Index articles published between 2001 and 2020. The annual numbers of articles, geographical locations of studies, major research organizations and authors, and the sources of journals on TCinRB were presented based on the analysis. Then, using co-authorship analysis, the collaborations among the major research groups were reported. Furthermore, research trends on TCinRB studies were visually explored using keyword co-occurrence analysis. The emerging research topics in the TCinRB research community were discovered by analyzing the authors’ keywords.FindingsThe findings revealed that studies had been discovered to pay more attention to north-east India, vernacular architecture, Hyderabad apartments and temperature performance in the past two decades. Thermal adaptation, composite climate, evaporative cooling and clothing insulation are emerging research areas in the TCinRB domain. The findings summarized mainstream research areas based on Indian climatic zones, addressed current TCinRB research gaps and suggested future research directions.Originality/valueThis review is particularly significant because it could help researchers understand the body of knowledge in TCinRB and opens the way for future research to fill an important research gap.

Performance of a novel climate-adaptive temperature and humidity independent control system based on zeotropic mixture R32/R236fa

• A climate-adaptive temperature and humidity independent control system (CATHICS) is proposed. • Heat and humidity ratio ( ε ) of CATHICS is adjustable to afford the changing heat and moisture. • Temperature glide of non-isothermal cooling sources change with the concentration of zeotropic mixture. • Effect of outdoor meteorological parameters and indoor personnel fluctuation on ε is analyzed. • The affordable ε of the CATHICS varies from 3500 to 4700 kJ/kg. A climate-adaptive temperature and humidity independent control system (CATHICS) is proposed, of which heat and humidity ratio ( ε ) is adjustable to afford the changing indoor heat and humidity load. Zeotropic mixture R32/R236fa is employed due to its characteristic of temperature glide during phase change. A module for composition regulation is incorporated based on boiling point difference of zeotropic mixture. High/low boiling point component increasing modes are operated when indoor air state deviates from the accuracy standard. Temperature glide regions of non-isothermal cooling sources change with the concentration of zeotropic mixture, which conforms to cascade utilization for moisture and heat load removal. The cooling and dehumidifying capacity of the chiller is regulated correspondingly. The models of evaporation temperature glide, affordable ε , cooling and dehumidification efficiency are established. The effects on the affordable ε are analyzed with the changing outdoor meteorological parameters and indoor personnel fluctuation. The relationship between mass concentration of working fluid and sliding temperature regions is revealed. The affordable ε varies from 3500 to 4700 kJ/kg, which illustrates that the CATHICS can totally afford changing heat and humidity load. The cooling and dehumidification efficiency are approximately 3.2 and 1.2. The vapor quality of the working fluid from the condenser is analyzed. The highly-integrated CATHICS is suitable for realizing individualized thermal comfort in residential buildings.

Construction strategy on outdoor environment of ecological community in dry region–Lanzhou, China

In order to improve the human thermal comfort of the ecological community, aiming at the characteristics of low humidity and large wind and sand in northwest areas such as Lanzhou, the method was proposed to improve the human thermal comfort by water evaporation from porous pavement. Firstly, the outdoor environmental model of the ecological community was established and the environmental parameters of a community are simulated by using the model in Lanzhou. The simulation results are compared with the experimental results, and the relative error is less than 15%. Secondly, the change law of outdoor thermal and humid environment is simulated and analysed when porous pavement and ordinary pavement are used in ecological community, respectively. The results show that the humid environment of the community has changed significantly and the maximum change is about 7% after considering the water evaporation from porous pavement. Meanwhile, the amount of single water sprayed onto the porous pavement should meet the water evaporation requirement of 1.67h under the climatic conditions at that time. The above research results provide theoretical guidance for improving the outdoor thermal comfort of residential buildings in dry region.

Comparison of residential thermal comfort in two different climates in Australia

Assessment criteria for thermal comfort in residential buildings are often defined on the basis of the adaptive comfort model due to their typical operational characteristics – i.e. mixed-mode or naturally ventilation. However, recent field studies demonstrate that the current adaptive comfort model prescribed in the international standard does not necessarily provide appropriate comfort criteria for residential buildings, since its occupants may be less thermally sensitive due to enhanced adaptability and greater tolerance of temperature variation. This paper examined perception of thermal comfort and behavioural adaptation of residents in two cities on the east coast of Australia – Sydney and Brisbane. With an aim to develop a method of deriving acceptable temperature ranges for different climate characteristics, statistical analyses were performed on two sets of longitudinal field study data collected in the two study regions. The statistical analysis estimates the acceptable temperature range for the two cities at around 11 K, which is 4 K wider than that prescribed by the ASHRAE's adaptive comfort model. The results also indicate that the 80% acceptability range can shift according to the climate, with 1.5 K difference being observed between the two study regions. The findings of this study can help climate-responsive design of houses, hence allowing the design to more closely meet occupants' comfort needs.

Impact of Window-to-Wall Ratio on Heating Demand and Thermal Comfort When Considering a Variety of Occupant Behavior Profiles

Energy consumption and thermal comfort in residential buildings are highly influenced by occupant behavior, which exhibits a high level of day-to-day and dwelling-to-dwelling variance. Although occupant behavior stochastic models have been developed in the past, the analysis or selection of a building design parameter is typically based on simulations that use a single “average” occupant behavior schedule which does not account for all possible profiles. The objective of this study is to enhance the understanding of how window-to-wall ratio (WWR) of a residential unit affects heating demand and thermal comfort when considering occupant behavior diversity through a parametric analysis. To do so, a stochastic occupant behavior model generates a high number of possible profiles, which are then used as input in an energy simulation of the dwelling. As a result, one obtains probability distributions of energy consumption and comfort for different WWR values. The paper shows that the shape of the probability distributions is affected by WWR and dwelling orientation, and that the influence of different occupant behavior aspects on performance also varies with WWR. This work could help designers to better assess the impact of WWR for a large spectrum of possible occupant behavior profiles.

Comparative assessment of thermal comfort with Insulation and phase change materials utilizations in building roofs and walls

Present study deals with estimation of thermal comfort of residential buildings for different scenarios. The three scenarios which are analysed for the present study are construction using brick wall and concrete roof, construction by utilization of insulation over walls and roof and construction by utilization of Phase Change Materials (PCM) over walls and roof.A building is simulated in EnergyPlus using conduction finite difference algorithm. The PCM is microencapsulated in plaster boards thereby restricting any chemical reactions with the building material. The assessment is carried out by calculating the hourly average room dry bulb temperature and average room relative humidity. This is then compared with the thermal comfort conditions provided in National Building Code of India 2005 and a percentage of hours within comfort range is worked out. The assessment is carried out between the months of March and October for three cities i.e. Bhubaneshwar, Jodhpur and New Delhi, all under different climatic conditions. The results indicate that PCM is performing comparatively better than insulation in improving the indoor conditions and that its performance can be greatly enhanced if the operating temperature is increased from 27°C to at least 30°C. Combined with the strategy of night ventilation and enhanced heat capacity storage, PCM could greatly enhance the thermal comfort levels. Copyright © 2017 VBRI Press.