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[Display omitted] • Localized heating systems are a proper solution for providing thermal comfort. • Providing personalized heating by radiation or conduction is more convenient, so the inhaled air is kept cool and pleasant. • Local radiant heating systems directly heat the body without heating the environment, leading to lower energy consumption. • With local radiant heating systems, proper thermal comfort and sensation can be achieved even at low air temperatures. Localized heating systems are a proper solution for providing thermal comfort while lowering energy consumption in cold environments. Local radiant heating systems provide thermal comfort at lower air temperatures than convective systems which heats air, resulting in cool and pleasant inhalation air. This paper reviews experimental studies regarding local radiant heating systems considering thermal sensation and comfort. These systems can heat body directly, often with a big view factor toward the body. They do not necessarily heat the air and environment, leading to lower energy consumption. Other types of heating systems combined with local radiant heating systems are also reviewed in this paper. According to reviewed studies, localized methods improved thermal comfort, and the same thermal sensation could be achieved in lower air temperatures, especially when using local radiant heating systems. To design local radiant heating systems properly, improvement of existing local thermal comfort and sensation modeling based on radiant heat transfer is needed. [ABSTRACT FROM AUTHOR]

Post-occupancy evaluation (POE) is necessary to evaluate the building's performance in order to formulate future design development after its utilisation. This paper evaluates indoor thermal performance, sound pressure level, and illuminance in a multipurpose auditorium by combining zoning and activity-based POE. The evaluation was done in three activities: (A) student graduation, (B) theater performance, and (C) public lecture with different types of clothing preferences. Three different zones were used to define the precise location of the building improvement. Field measurements were taken for thermal performance, including Operative Temperature (T op), Humidity (Rh), Sound Pressure Level (dB), and Illuminance (lux). User perceptions were collected from 171 respondents (89 men and 82 women). The field measurement showed that average operative temperature varied across the activities with 26.15–25.68 °C, 25.47–24.95 °C, and 23.74–23.17 °C on activities A, B, and C, respectively. Activity A's (1 clo) room's operative temperature showed that 65% of data are outside the ASHRAE standard, indicating that the room condition is unsuitable for 1 clo. Activity A's TSV shows a slightly warm sensation (0.21 to 0.93) and is still in the comfort range. With the same clothing value (0.6 clo), Activity B's T op indicates a more suitable condition than Activity C's. The average TSV in Activity B indicates slightly cool (-0.54 to −0.90), with the lowest TSV found in Activity C (-1.09 to −1.41). Although TSV positively correlates with PMV , Thermal Preference (TP) revealed that the occupant expects cooler conditions in all activities. Sound pressure level and illuminance performed well according to all activities. This paper recommends chiller setting adjustment in the multipurpose auditorium based on activity characteristics. Combined POE based on zoning and activity can indicate which aspects of the auditorium need to be improved. [ABSTRACT FROM AUTHOR]

• Climate change and urban setting impact energy use of buildings. • Energy use is higher due to overlapping effect of climate change and microclimate. • A method is proposed to account for future and urban environment in thermal simulation. • The results can assist in sizing passive ventilation systems. Urban settings and climate change both impact on energy use and thermal comfort inside buildings. This paper first presents a study of changes in energy demand in residential buildings considering the overlapping effect of climate change and urban heat island intensity in two European locations; Cadiz (Spain) and London (United Kingdom), representing temperate and hot European climates and moderate and dense urban settings. Future-urban weather files were generated and simulations were run considering energy demand and indoor thermal comfort. In hot climate regions such as the one of Cadiz, future climate will increase the cooling demand and the additional impact of the UHI leads to a further increase of up to +28% of total energy demand compared to the current climate without considering urban effects. Future-urban weather conditions will be detrimental also for buildings in London, where the annual energy demand is predicted to increase by up to the 16% if future climate and urban effects are included. This is due to a higher increase in cooling demand compared to the reduction for the heating need. The paper also presents a method to take into account microclimatic conditions in naturally ventilated buildings, especially the effect of wind variations around the building which impacts natural ventilation rates. Air and surface temperature and wind speeds were studied using ENVImet and the resulting microclimatic conditions were used as inputs to the EnergyPlus Airflow Network model for the calculation of the building ventilation rates. It was found that ventilation rates are reduced (in comparison to meteorological weather files) and this reduction impacts negatively on internal operative temperatures. A thermal comfort analysis was carried out indicating that the selection of a suitable weather file and microclimatic conditions is essential for more accurate predictions of internal thermal comfort and will assist in the sizing of passive and active systems to avoid overheating. [ABSTRACT FROM AUTHOR]

The optimization of HVAC system control affects the thermal comfort of building environment and air-conditioning energy consumption. However, most existing studies concentrate on human thermal comfort and neglects to incorporate air-conditioning energy consumption required to establish a controlled indoor thermal environment within the policy, which results in air-conditioning system high energy consumption. This paper suggests an indoor temperature intelligent control method based on thermal comfort and energy consumption of air-conditioning, and the TD3 algorithm is employed as an intelligent control algorithm to obtain the optimal setpoint that maximizes the joint benefit of the occupant's thermal comfort and the energy saving rate of air-conditioning system. The air-conditioning indoor temperature intelligent control model based on TD3 algorithm is trained by using the experimental data, and the method is simulated in TRNSYS simulation software to corroborate the efficacy and energy saving rate of the method. The results indicate that the indoor temperature intelligent control model based on thermal comfort and energy consumption of air-conditioning has less optimal adjustment of indoor temperature setpoints, which is more stable for the air-conditioning system and can satisfy the thermal comfort demand at the initial control stage to prevent significant fluctuations in human thermal sensation compared to the linear control method based on thermal sensation and the fuzzy control method based on thermal sensation. Besides, the average daily energy consumption can be reduced by 6.54% and 3.37% respectively, when compared to the linear control method based on thermal sensation and the fuzzy control method based on thermal sensation. [ABSTRACT FROM AUTHOR]

• Oil fume control, thermal comfort and energy of commercial kitchen are explored. • Demand exhaust rate of fume hood is determined on oil control effect. • Conditioned air supply parameters are determined on thermal comfort. • On-demand ventilation reduces ventilation and air conditioning energy by 71.16%. • Airflow optimization reduces airflow by 20% and energy by 50.81%. To analyze the energy-saving potential of commercial kitchen ventilation and air-conditioning (VAC) systems and to create a good kitchen environment, this paper calculates the key influential parameters of the exhaust air volume and air supply temperature through CFD simulation. The former depends on the fume control effect and is closely related to the make-up air method, while the latter is governed by the thermal comfort. The energy consumption under different operational strategies is calculated using EnergyPlus. The following conclusions were obtained: (1) By summing the demand exhaust rate of the cookers with that of the fume hoods during the operation of multiple cookers, the pollution control effect can still be satisfied. Moreover, the airflow can be reduced by 20% through airflow optimization. (2) During summer, the conditioned airflow should constitute 30% of the total make-up air volume, with an air supply temperature of 22 ℃. Conversely, in winter, the conditioned airflow should comprise 40% of the total make-up air volume, with an air supply temperature of 14 ℃. (3) It is advisable to use a personalized conditioned air supply to create a local thermal environment, effectively reducing the energy consumption of ventilation and air conditioning systems. The energy-saving rates achieved through airflow optimization and on-demand ventilation are 51% and 71%, respectively. [ABSTRACT FROM AUTHOR]

• Indoor-quality oriented approach is proposed for building post-retrofit analysis. • The approach is based on readily monitored indoor data and on mangers and users' opinions. • As case study, the student dormitory of University of Athens is presented. • Thermal comfort indices greatly vary with management strategy and personal choices. • The analysis of indoor air quality highlights the key role of mechanical ventilation. The rapid expanding of refurbishment incentives requires to deserve more attention on how to reach nearly zero energy standard without compromising occupant wellness, when the building is undergone to important architectural transformations. To overcome the above drawbacks mainly for student dormitories, the paper introduces a new indoor quality oriented post-retrofit evaluation approach that simultaneously quantifies the impact of design decisions on thermal, respiratory and visual comfort. Investigations on the building quality and readily monitored indoor variables are the core of the approach that also provides sensitivity analysis on some subjective parameters and questionnaires for the main involved stakeholders. The proposed approach is tested on a student dormitory belonging at National and Kapodistrian University of Athens, refurbished in the frame of Horizon Project Pro-GET-OnE. The results reveal an improvement in the passive control of thermo-hygrometric comfort as well as in the satisfaction level. The adoption of mechanical ventilation consistently ensures dioxide emissions lower than 430 ppm, TVOC below 300 μg/m3 and PM2.5 and PM10 lower than 6 μg/m3. More in general, it is remarkable the importance of considering all comfort domains and occupant behavior, as one design or management choice might improve one indoor quality domain at the cost of others. [ABSTRACT FROM AUTHOR]

• Overheating regulations and calculation methods in 26 European countries were compared. • Most of the existing calculation methods are outdated and do not fit climate-proof buildings. • France requires a mixed-mode operation of naturally ventilated households. • The UK developed a heatwave-based calculation approach. • Comfort-based, multi-zonal, and time-integrated calculation approaches are needed. With the ongoing significance of overheating calculations in the residential building sector, building codes such as the European Energy Performance of Building Directive (EPBD) are essential for harmonizing the indicators and performance thresholds. This paper investigates Europe's overheating calculation methods, indicators, and thresholds and evaluates their ability to address climate change and heat events. e study aims to identify the suitability of existing overheating calculation methods and propose recommendations for the EPBD. The study results provide a cross-sectional overview of twenty-six European countries. The most influential overheating calculation criteria are listed the best approaches are ranked. The paper provides a thorough comparative assessment and recommendations to align current calculations with climate-sensitive metrics. The results suggest a framework and key performance indicators that are comfort-based, multi-zonal, and time-integrated to calculate overheating and modify the EU's next building energy efficiency regulations. The results can help policymakers and building professionals to develop the next overheating calculation framework and approach for the future development of climate-proof and resilient residential buildings. [ABSTRACT FROM AUTHOR]

• This paper presents a comprehensive review of cross ventilation research in buildings. • The advantages and disadvantages of different research methods are compared. • The ventilation models of cross ventilation are reviewed. • The influencing parameters of cross ventilation are summarized. • The future perspectives of cross ventilation research and practical applications are proposed. There is a growing body of literature that recognizes that natural ventilation plays a vital role in indoor air quality, thermal comfort and building energy consumption. This paper systematically reviews the previously published research of the most efficient and typical natural ventilation type - cross ventilation, aiming to present the main research topics in contemporary research and provide an agenda for future studies. The methodologies, airflow pattern, ventilation models and influencing parameters of cross ventilation were comprehensively summarized and discussed. The chained analysis and data-driven methods are the potential approaches to study cross ventilation more efficiently. The comparisons of different ventilation models of cross ventilation help to better understand the basic mechanisms that drive the cross ventilation airflow. [ABSTRACT FROM AUTHOR]

Diagrams of (A)conventional cool roofs, (B) super cool roofs, and (C) temperature-adaptive roofs whose color can change with temperature. [Display omitted] • Cool roofs are divided into conventional cool roofs, super cool roofs, and temperature adaptive roofs. • The use of cool roofs is limited by geography and climate, with the net cooling power of up to 150 W/m2 in dry, rainless, and clear sky areas. • The use of cool roofs in cities may cause light pollution problems, which can be alleviated by special structures or materials. • Not only does atmospheric water vapor affect the radiative cooling power of cool roofs, but in turn, cool roofs can increase the water vapor content above the roof. • The large-scale use of super cool roofs may affect the urban wind field. Cool roofs play a significant role in mitigating urban heat islands, improving indoor thermal comfort, and saving energy. In recent years, with advances in the manufacturing of nanophotonics and metamaterials, researchers have developed super cool roofs where the surface temperature remains below the air temperature in direct daylight and temperature-adaptive roofs where the solar reflectance or thermal emissivity can change with temperature. This paper reviews the research progress and status of conventional cool roofs, super cool roofs, and temperature-adaptive roofs. This paper affirms the role of cool roofs in mitigating urban heat islands and energy conservation. And this paper also summarizes some of the crucial issues that cool roofs may face when used in cities. The effects of cool roofs on urban wind fields, planetary boundary layer heights, and pollutants above cities as well as the effects of sky view factor, atmospheric humidity, dust, and aging on the performance of cool roofs are discussed. The results show that the use of cool roofs is limited by geography and climate. The net cooling power can reach 150 W/m2 in dry, rainless, and clear sky areas. Cool roof technology is less effective in hot and humid climates because the first atmospheric window is affected to varying degrees by the increased radiation medium in the atmosphere, while the second atmospheric window is nearly closed in hot and humid climates, weakening the terrestrial long-wave radiation entering space. The use of cool roofs in warm and humid climates (over 80% relative humidity, with temperature over 24 °C) for most summer nights may limit the radiative cooling performance of the cool roof. The large-scale use of cool roofs in cities near huge lakes or seas may affect the urban wind field, causing a cooling island effect and a local build-up of pollutants. Finally, an outlook on the research prospects of cool roofs was given to provide ideas for further research. [ABSTRACT FROM AUTHOR]

• The physiological equivalent temperature (PET) and the universal thermal climate index (UTCI) are considered adaptive thermal comfort evaluation indices applicable to transition space. • The strong wind is prone to occur in winter on Huajiang campus. It is important to take precautions against the discomfort caused by a strong wind. • The outdoor thermal comfort condition of Huajiang campus in summer is better than it in winter. • Adjusting the coverage of lawn, marble floor, water surface and landscape trees can effectively regulate the microclimate of the library's inner courtyard space. The inner courtyard is an important transition space for mass exchange and heat transfer between the internal space of courtyard buildings and the external environment. A good layout of courtyard space is conducive to building energy efficiency and human thermal comfort. In the paper, we analyze the impacts of different design schemes of the spatial layout on the microclimate of inner courtyard space using field measurements and numerical simulation methods. The analysis of the measured data presents the main meteorological factors affecting the thermal comfort of the courtyard. The magnitude of the effects is ranked as air temperature, total solar radiation intensity, near-surface air flow rate, and relative humidity. Results of the ENVI-met simulation show that changing the cover of different underlying surface types leads to different microclimate regulation effects in the sense that the temperature and relative humidity in summer drops up to 3.53 °C and 15.59%, respectively and in winter increase up to 3.97 °C and 37.21%, respectively. This paper proposes that lawn ground, marble ground, water surface and landscape tree coverage of 25%, 25%, 50% and 75%, respectively, are suitable design schemes for the inner courtyard space of library. [ABSTRACT FROM AUTHOR]

This paper presents a novel radiant heating system with a wall-embedded micro heat pump (WEMHP) for residential buildings. The interior surface temperature of the exterior wall-section empowered by the micro heat pump is independently controlled, enabling distributed thermal comfort delivery. The micro heat pump consists of a miniature compressor along with an aluminum roll-bond condenser and evaporator. In contrast to conventional hydronic radiant systems and heat pumps with separate indoor and outdoor units (i.e., split systems), the WEMHP is a "packaged" system that would not require on-site installation and charging of a secondary water loop and circulation pump or refrigerant piping. This could ultimately lead to reduced installation and maintenance costs. In this study, a detailed system model is presented and integrated with a single-zone building model to assess the energy performance of the WEMHP in heating mode. For a designed living room scenario with an external wall WEMHP-to-wall ratio (HPWR) of 0.6 and window-to-wall ratio (WWR) of 0.2, the simulation results show that up to 23 % energy savings compared with a baseline air-to-air heat pump are possible. The results also indicate the HPWR needs to be higher than 0.4 to achieve performance comparable to the baseline. Additionally, experiments were conducted in a laboratory environment in which surface temperatures were controlled to emulate different scenarios for integration of WEMHP technology and to evaluate thermal comfort conditions. The experimental results show that the median operative temperature differences in the indoor environment were within 0.5 °C for various locations while the largest radiant asymmetry was 2.2 °C for the designed room configuration. Moreover, simulations were conducted to evaluate thermal comfort conditions in applications having a smaller HPWR of 0.4 with various values of WWR. Overall, the combined simulation and experimental study shows that the WEMHP has potential to reduce energy use while maintaining thermal comfort at acceptable levels where the HPWR is higher than 0.4. [ABSTRACT FROM AUTHOR]

The impact of data characteristics on dataset quality is of significant guidance in the field of thermal comfort field surveys. In this paper, a Chinese thermal comfort database has been established, comprising quality-controlled on-site survey data. The database encompasses 41,977 sets of on-site survey data collected from 50 cities across 24 provinces, spanning a period of nearly 20 years from 2001 to 2021. It includes the five thermal zones in China and encompasses three seasons—summer, transitional, and winter—as well as four types of buildings: office buildings, residential buildings, student dormitories, and classrooms. The database exhibits an extensive data distribution, demonstrating a certain level of representativeness in terms of environmental temperature and survey locations. Based on this established database, the thermal sensation model was employed as the criterion for evaluating dataset quality. This study analyzed the impact of data characteristics on dataset qualityfrom three perspectives: sample size, data distribution, and data range. A sample size calculation method using interval estimation was adopted, determiningthat a minimum sample size of 350 is required for on-site thermal comfort surveys in office and residential buildings. A comparison revealed that compared to data with the normal distribution and uniform distribution, data with the positively skewed distribution exhibit lower neutral temperatures, while data with the negatively skewed distribution exhibit higher neutral temperatures. The thermal sensation model constructed based on data with uniform distribution demonstrates greater robustness. As the temperature range decreases, the neutral temperature increases in winter and decreases in summer, resulting in reduced accuracy of the constructed thermal sensation model. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two modules were analyzed during Antarctic summer at Spanish research station. • Measured transmittances and infiltrations were excessively high, resulting in high energy consumption for heating. • Indoor air conditions were poor in both modules, particularly the CO 2 concentration. • Extreme weather conditions accelerated the degradation of insulating materials and sealants. • Energy efficiency standards are urgently needed to improve the carbon footprint of Antarctic bases. In this paper, we present the energy characterization of two habitable modules at the Spanish station "Gabriel de Castilla", located on Deception Island, Antarctica. The analysis includes profiles of energy consumption for space heating and domestic hot water, as well as indoor air conditions, which were all recorded during one month of Antarctic summer. Additionally, the measurement of walls' transmittance and air infiltrations, together with thermography analysis, enabled evaluating the conservation state of the buildings' envelope. Upon analyzing all this data, it is evident that there is potential to enhance the design of future modules, improving the thermal comfort while significantly reducing the energy consumption. This will contribute to decrease the logistics and environmental impacts of these research stations, crucial considerations in human activity on the Antarctic continent. [ABSTRACT FROM AUTHOR]

Natural building materials, including bioaggregates and biocomposites, have been making a comeback in recent years, in an attempt to minimize the Embodied and Operational Energy and Carbon (EE, OE, EC, OC) related to construction. This paper presents monitoring results of three buildings (two residential and one educational) built with such materials in the Mediterranean climate of western Crete. Temperature and relative humidity monitoring results show a very stable indoor environment behavior even when the buildings were unoccupied, thus not appropriately operated. Additional measurements undertaken and presented here include CO 2 concentration in the occupied residential building with a combustion heater; and blow-door tests to better understand infiltration issues related with such construction. Results analysis shows that such materials are appropriate alternatives, definitely in bioclimatic building design for the specific climate. Indoor conditions analyzed vis-à-vis the adaptive thermal comfort model are shown to be within the thermal comfort zone, almost for all climatic conditions. [ABSTRACT FROM AUTHOR]

Model Predictive Control can cope with conflicting control objectives in building energy managements. In terms of user satisfaction, visual comfort has been proven in several studies to be a crucial factor, however thermal comfort is typically considered the only important aspect. Besides human well-being, visual comfort strongly impacts the productivity of the occupants in offices. Therefore, from an economic point of view, it is essential to include visual comfort in Model Predictive Control for buildings. In this paper semi-linear support vector machine is applied to learn suitable models for visual comfort measured by Daylight Glare Probability. The resulting model is incorporated into a Model Predictive Control framework, together with an autoregressive exogenous model accounting for the thermal dynamics of the building. The approach is validated through an extensive numerical case study, and the benefits of including visual comfort and blind control in the Model Predictive Control problem are evaluated. We observe that the proposed Model Predictive Control scheme ensures both the thermal and visual comfort constraints at the expense of 2.2 % to 7.2% higher energy consumption compared to the benchmark Model Predictive Control configuration, which considers only the thermal comfort constraints. [ABSTRACT FROM AUTHOR]

• Experiment in three homes using mixed-methods and physical measurements. • Indoor air temperature fluctuations like those of EMPC of space heating. • Night setback-users found the heating control unacceptable. • Acceptance was motivated by economic or environmental benefits. Recent simulation-based studies have indicated that Economic Model Predictive Control (EMPC) of space heating systems can exploit the thermal mass in residential buildings for demand response (DR) purposes in district heating systems. However, there is a lack of studies on residents' perception and acceptance of the fluctuating indoor air temperature behaviour inherent in EMPC of space heating. This paper reports on a case study featuring the residents of three one-story houses located in Denmark. The houses were equipped with technology enabling remote actuation of radiator thermostats and collection of various indoor environmental data. Four different temperature boost interventions mimicking the typical behaviour of EMPC of radiators were executed while a mixed-methods triangulation design, employing questionnaires and semi-structured interviews, was used to collect subjective data. Data showed that residents accepted the behaviour but only after the benefits of the EMPC were explained. The acceptance was motivated by either the prospect of saving money, environmental benefits, or a combination of both. The results thereby indicate that explaining the benefits of EMPC is important if residents are to abandon their current preferences and practices in favour of an EMPC concept. The explanation should consider the diversity in current preferences, expectations, and level of technological pre-knowledge. In addition, the paper also reports on a range of findings related to technical aspects of realising EMPC in practice. [ABSTRACT FROM AUTHOR]

• Secondary students' thermal comfort was explored in the countryside throughout one year. • Comfort indicators and behavioral adaptation were determined in different seasons. • The applicability of the adaptive comfort model was demonstrated in different seasons. People experience four seasons every year, and their thermal comfort usually changes with the season. However, a little is known about the dynamic characteristics of secondary students' thermal comfort in the countryside under different seasons. This study aims to investigate thermal comfort of students in the countryside under various seasons and reveal the underlying mechanism. One year long-term field study was conducted in a countryside secondary school in Hengyang City, located in the hot summer and cold winter zone of China. A paper questionnaire was used to collect subjective thermal comfort. The surrounding physical environment was also measured. A total of 450 subjects voluntarily participated and returned 2349 valid datasets. The results indicated students had the lowest acceptance rate with temperature (71.9 %), humidity (74.9 %), and velocity (70 %) in summer season. Neutral temperature was 25.7 °C in summer, 19.2 °C in transition, and 14.9 °C in the winter. An inverted U relationship was found between perceived air quality and air temperature. Cold extremities (53.0 %), shivering (37.2 %), and stuffy nose (60.4 %) were prevalent in winter. Adaptive comfort model was only effective in the summer in naturally ventilated secondary school buildings. Estimated learning performance was the highest in transition and lowest in summer. Behavioral adaptation was determined by the relationship between air velocity clothing insulation and operative temperature. The findings of this study provide fundamental knowledge of thermal environment, subjective comfort, and health status in naturally ventilated educational buildings in countryside area. Engineers and designers can use professional comfort indicators to guide their future construction or renovation. [ABSTRACT FROM AUTHOR]

One of the major challenges with increasing penetration of renewable energy sources (e.g., solar and wind) is to maintain grid stability. Grid-interactive efficient buildings are regarded as a promising approach to advance the role buildings can play in energy system operations and planning. This paper evaluates the demand flexibility in a residential building located in Karlsruhe, Germany, incorporating multiple distributed energy resources, including a photovoltaic and battery system, an electric vehicle, an electric water heater and a heat pump. A multi-criteria optimization problem is formulated with model predictive control (MPC) for five cases of demand flexibility. The simulation results of five winter days show that the peak power during the peak periods can be reduced by 92%, 69%, 100%, and 100% for real-time pricing, demand limiting, load shedding, and load shifting, respectively. For the power tracking scenario, the MPC tracked the reference power profile successfully for 70% of the simulation time. Achieving demand flexibility does not necessarily cause an increase in energy costs. • Distributed energy resources include thermostatic loads, PV, battery, and electric vehicle. • Real-time pricing, load shedding, shifting, and power tracking are considered. • An approach to maximize load sheaving and shifting is proposed. • Providing demand flexibility does not necessarily increase energy cost. [ABSTRACT FROM AUTHOR]

• Climate change's impact on retrofitting was tested on Le Corbusier's apartment. • Climate change scenarios project up to 70% increase in summer overheating. • Adaptive natural ventilation can reduce warm discomfort of 50–60%. • Adaptive setpoints can reduce total energy consumption of 20–30%. • Adaptive strategies are particularly favourable in historic buildings. Historic buildings, often exempt from retrofits to preserve originality, require retrofitting due to potential future climate-related indoor issues. For Modern Architecture constructions, there is a need to find solutions that help address the discomfort and heat losses caused by the extensive use of glazing. By analysing Le Corbusier's studio-apartment this paper aims to inspect: (i) Solutions for energy, Indoor Environmental Quality, and preservation; (ii) Climate change impact on them; (iii) Possible adaptation strategies to cope with climate change. Spectrally selective glazing reduced summer overheating by 15%; high-performance glazing lowers cold discomfort (24%) and heating (22%) but increased warm discomfort; shadings maintained energy use and reduced summer discomfort by up to 44%; thermal insulation can reduce winter discomfort and halves energy use but raised summer discomfort by up to 41%. Tests on 2050–2100 climate change scenarios reveal up to 70% more warm discomfort hours. Adaptive strategies can help, with natural ventilation cutting warm discomfort by 50–60%, and adaptive setpoints reducing cooling demand by about 35%. Adaptive strategies can complement traditional retrofitting in addressing current and future climate conditions, especially in historic buildings that require minimal interventions to preserve their historical characteristics and enhance resilience. [ABSTRACT FROM AUTHOR]

Personalized thermal sensation models play a crucial role in ensuring occupant's thermal comfort satisfaction and improving building energy efficiency. However, an adaptive and accurate personalized model that can be easily implemented in real life is still challenging. This paper investigates the influencing factors of thermal sensation vote (TSV) and proposes a personalized regression model that only uses a single local skin temperature as the key indicator. A survey is conducted with forty subjects aging from 20 to 59 years old. The relationship among ambient temperature, skin temperatures, and subjective TSV is analyzed. The forehead temperature is recommended as the key indicator for prediction because it exhibits a strong correlation with ambient temperature and TSV, and it is easy to capture. Furthermore, the impact of individual characteristics on TSV is investigated. The proposed model effectively captures and compensates for individual differences by incorporating subjects' set point skin temperature and body fat percentage (BF%). The proposed model can be readily applied in real-life scenarios due to its minimal requirement for occupant's feedback and its higher accuracy compared to other models. Specifically, it exhibits a significantly lower Root Mean Square Error (RMSE) of 15.8 %, 9.4 %, and 65.2 % compared to the Support Vector Regression (SVR) model Zhang's model and Zhou's model. Moreover, the proposed model showcases the lowest mean absolute error among the compared models. This approach of developing a personalized regression model based on local body temperature holds promise for future international ergonomic standard development. [ABSTRACT FROM AUTHOR]

• A metodology for evaluating comfort temperature ranges is carried out. • New evaluation metrics regading thermal comfort and energy savings are proposed. • Quantitative evaluations of modifying thermal comfort ranges are provided. The selection of a suitable indoor temperature is a challenge to society, since its relationship with thermal comfort and energy consumption. The adaptive thermal comfort theory addresses this problem relating indoor with outdoor temperatures and based on that, defines temperature ranges. This paper defines a fuzzy logic-based methodology to assess the suitability of indoor adaptive temperature ranges proposed by existing regulations of the real thermal sensation of the occupants. For this purpose, the study suggests considering four indicators to evaluate the representativeness of different comfort ranges on the real preferences of the occupants. Based on that, four metrics are proposed for interpreting the needs of the occupants of a building and the changes required to the temperature ranges to satisfy such needs. To validate the proposed methodology, questionnaires on the thermal sensation of the occupants of office buildings considering three case studies (Mediterranean, Europe, ASHRAE) are used, showing the results obtained the representativeness of adaptive comfort ranges for such databases. The feasible introduction of this methodology in a conditioning systems would assist in decision making regarding energy efficiency, thermal comfort and a balance between them. [ABSTRACT FROM AUTHOR]

[Display omitted] • Infrared technology enables non-invasive temperature measurement. • Existing literature related to personal thermal comfort using infrared technology was reviewed. • Measurement equipment, experimental conditions, subject's information, and analytical methods were analyzed. • Accurate predictions should be translated into control commands for the equipment at different scales. • Diverse application scenarios including car cabin, sleep, and outdoor environments were discussed. Personal thermal comfort studies are crucial for balancing both human comfort and building energy savings. Thus, personal comfort models (PCMs) are expected to play a pivotal role in the development of smart buildings. Infrared technology has received significant attention from researchers because of its non-intrusive nature for collecting personal data. This systematic review examined 36 personal thermal comfort studies that employed infrared technology over the past decade. The review analyzed the (1) infrared devices, (2) experimental designs, (3) subjects, and (4) analysis methods and results. The review found that most studies were experimental and focused on exploring feasibility at a theoretical level, while the number of practical application studies was limited. The accuracy of infrared devices was identified as a primary concern for researchers, and some studies proposed methods to mitigate measurement errors. Most studies included young subjects and examined single clothing insulation and metabolic rates, limiting the generalizability of the corresponding PCMs, which were mainly constructed using machine learning. To facilitate data sharing and comparison of results and to overcome the limitations in terms of applicable populations and application scenarios, the review suggests that standardized data collection and processing should be used in future studies. Furthermore, the paper proposes the integration of PCMs and personal comfort systems, which are two hotspots in personal thermal comfort research, to achieve cooperative applications. Finally, the study discusses the future applications of infrared technology in scenarios such as vehicle cabins, sleep areas, and outdoor environments, considering their unique characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • nZEBs in Eastern Europe lack carbon neutrality metrics and targets. • Performance requirements for nZEBs in Eastern Europe are presented. • Eastern Europe needs strategy and local governance for nZEB market penetration. • EPCs require major reform, and effective monitoring of nZEB performance is needed. • The cost-optimality calculation method must be adopted to ensure cost-effective market uptake. The European Unions' ambition for the construction sector is to be carbon neutral by 2030 for new construction. Since 2021, all new buildings in the EU should have been constructed as nearly zero-energy buildings (nZEB). However, Eastern European countries struggle to implement the 2018 Energy Performance of Building Directive recast requirements. Next to the economic challenges, equally essential factors hinder renovating the existing residential building stock and adding newly constructed high-performance buildings sourced primarily from renewable energy sources. Therefore, this study provides a cross-study to identify the barriers to nZEB implementation in ten Eastern European countries, including Bulgaria, Croatia, Czechia, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, and Slovakia. The study was conducted between 2019 and 2021 and provides an overview of prospects for nZEB in Eastern Europe. The study examines the challenges of nZEB plans faced in those countries and provides constructive recommendations. The regulations and definitions regarding nZEB energy performance, cooling and heating energy demand, thermal comfort, onsite renewables, and construction quality were analyzed. Results show that most Eastern European countries are unprepared to comply with the EPBD guidelines and cost-optimality approach. The paper ranks each country and recommends specific measures to refine the nZEB definitions. The paper provides a thorough comparative assessment and benchmarking of select EU geography that can help shift the identified gaps into opportunities for the future development of climate-neutral high-performance buildings. [ABSTRACT FROM AUTHOR]

This paper investigates experimentally the cooling performance of a concept, where the radiant ceiling is suspended from the hollow-core concrete slab and by ventilation supply in the plenum and the perforations of the ceiling tiles, ventilation air is distributed without ducts and air terminals to the occupied zone. Literature has proven that this concept allows for more streamlined installation procedures and excellent performance in terms of thermal comfort and draught. The paper reports experimental results from a climate chamber, where the concept was tested under both steady-state and quasi-steady conditions. The steady-state conditions were chosen to map the cooling performance with different air change rates, and different ventilation and water supply temperatures. The results showed that for air change rates of 3 h−1 in the occupied zone and water supply temperature of 17 °C, the cooling output from the ceiling increased by 10 %. The concept was also tested under quasi-steady conditions in a 48 h cycle to quantify the thermal buffering effect of the exposed upper concrete slab when subjected to ventilation supply air. The effect amounted to 11–12 % increased cooling capacity at the end of the working day when the driving temperatures between air, water and thermal zones were at their maximum. [ABSTRACT FROM AUTHOR]

Traditional air-conditioning systems are energy intensive and contribute to higher operational costs especially in summer. This paper examines and compares the performance of two cooling systems in a room: one with a cooling tower connected thermally activated building system (TABS) combined with a fan coil unit (FCU), and the other with a conventional inverter split air-conditioner (AC). Natural ventilation adversely affected indoor air temperatures in TABS room while integrating FCU operation reduced the temperature by 5 °C and AC provided the most comfortable temperature. Thermal comfort survey of three occupants showed significant inconsistencies with Fanger model particularly for TABS with FCU and TABS without ventilation cases, as occupants felt comfortable indicating the positive effect of only sensible cooling. Energy consumption studies show that TABS in closed condition and with natural ventilation as the most energy efficient with AC being least efficient of the four systems. In terms of overall comfort and energy consumption for continuous operation throughout the day, TABS integrated with FCU was deemed the best option. [ABSTRACT FROM AUTHOR]

In response to the increasing demand for thermal comfort and the rising trend of building energy consumption in the hot summer and cold winter (HSCW) zone of China, there is an urgent need to implement higher standards of energy retrofit programs for existing residentials. Practical strategies and technical solutions still need to be improved in China. The Passive House standard (and its EnerPHit standard) aims to achieve ultra-low operational energy consumption through passive strategies. However, studies and examples of passive houses and low-energy buildings are rare in hot climates, especially in the HSCW zone of China. This paper presents the representative of the existing residential in Guilin, China. Simulation modeling through DesignBuilder and a sensitivity analysis were performed to conclude that airtightness, envelope, glazing type, and roof are the most critical factors affecting the energy consumption of the building. Furthermore, the combined solution was validated by optimizing the different retrofit parameters, resulting in a model that meets the energy objectives. The feasibility of the combined solution was also analyzed from the energy, economic, and thermal comfort points of view. Ultimately, the optimal solution that meets the objectives is obtained through a multi-criteria decision making (MCDM) approach for a more sustainable building. The methodology and results of this study provide an effective decision-making process for designing and evaluating energy retrofits for typical residential buildings in the HSCW zone, as well as a rigorous basis for policymakers to update the design codes for retrofitting buildings in HSCW zone. [ABSTRACT FROM AUTHOR]

• An optimization algorithm is developed for determining optimal flexible workplaces. • The thermal comfort models in the objective function are learned from personal data. • The optimization allows a customized trade-off between thermal comfort and energy consumption. • The algorithm is verified using both collected data and the ASHRAE database. Due to distinct preferences across individuals, a large proportion of people are not satisfied with the thermal environments of their workplaces. Although recent studies have investigated flexible workplaces to meet the different preferences of individuals, the feasibility of adopting them to real-world environments is limited by the room capacity and potential for extra energy consumption. To address the knowledge gaps, this paper proposes a framework to jointly optimize thermal comfort and energy consumption of buildings through flexible workplaces by considering personal thermal preferences. A joint optimization algorithm that integrates building energy and personal thermal comfort models is developed based on the concept of the Large Neighborhood Search (LNS) algorithm. Analytical energy prediction models are obtained through Nonlinear Polynomial Regression (NPR) and personal thermal comfort models are established using Support Vector Machine Models (SVM). To verify the algorithm, a case study considering two scenarios (with and without existing personal thermal comfort data) is presented. The results indicate the proposed optimization algorithm can significantly improve the thermal comfort of the occupants while saving 22% and 14 % of energy consumption in the two scenarios, respectively. The proposed optimization method is valuable for building managers while adopting the concept of flexible workplaces. [ABSTRACT FROM AUTHOR]

Several studies have indicated that Economic Model Predictive Control (EMPC) of residential space heating systems can exploit the building thermal mass to provide demand response for the energy supply system by boosting the indoor air temperature prior to peak load periods. The practical uptake of EMPC is thus dependent on whether residents accept the fluctuating indoor air temperatures induced by this form of EMPC. Evidence on this aspect is scarce but a few studies indicate in hindsight that it might be important to explain the economic and environmental benefits of an EMPC if residents are to abandon their current preferences and practices in favour of an EMPC concept. The objective of the study reported in this paper was therefore to investigate whether residents of three single-family homes actually would accept the fluctuating indoor air temperature induced by EMPC when being aware of environmental and/or economic benefits. The results suggest that residents are willing to accept the fluctuating indoor air temperature being aware of economic and environmental benefits – as long as the fluctuations do not make them feel too cold. [ABSTRACT FROM AUTHOR]

• Statistical analysis of the performance of a green wall in a Mediterranean climate. • Irradiance is discarded as a variable affecting the adjacent temperatures reduction. • Maximum reduction of 0.63 °C in summer and 0.54 °C in winter at 1 m from the south facade. • Maximum reduction of 2.3% HR in winter at 1 m from the south façade. • Reduction average of 0.9% HR in summer at 1 m from the south façade. A study has been performed to quantify the impact of a green wall temperature reduction in a continental Mediterranean climate. This paper presents the results of a monitoring campaign during the summer and winter of 2021–2022. First, a database was elaborated with information on air temperature and relative humidity at four different distances from the wall (0.25, 0.50, 0.75, and 1 m) and irradiance in the vertical plane. Secondly, a statistical analysis was carried out to determine whether there is a correlation between these variables and whether there are statistically significant differences between them at different distances from the wall. Results show a strong positive correlation between air temperature recorded by sensors and the ambient air temperature for all seasons and between air temperature and relative humidity in summer. The ANOVA shows that the green wall reduces the temperature and relative humidity with statistical significance for most of the cases. These results confirmed the great capacity of green walls to improve the urban microclimate, especially during summer, by reducing air temperatures, providing evidence that greening the building envelope can complement conventional city green infrastructure and provide multiple ecosystem services to dense urban contexts. [ABSTRACT FROM AUTHOR]

This study assesses the impacts of sustainable urban development adapted to climate change in the city of Stuttgart, Germany. We use the state-of-the-art meteorological modelling system PALM-4U to simulate the microclimate and outdoor thermal comfort of the development site Neckarpark during a heatwave. We compare the atmospheric conditions of the current urban structure before the development project (2018) and the future state, representing the new district after completion (2025). Our results indicate that the restructuring barely affects surrounding neighbourhoods, but leads to mean near-surface air temperature increases in the centre of development between ▪ and ▪. Differences in Physiologically Equivalent Temperature (PET) show a heterogeneous pattern at daytime, with a large amplitude and temporal variability in the diurnal cycle (▪). At night, the planned buildings increase the mean PET by ▪. The new buildings reduce the effect of adaptation measures designed to increase the cooling effects, i.e. urban trees and vegetation, amplifying the thermal stress during heatwaves. Our study confirms the complex composite impacts of urban restructuring due to the thermal and dynamic flow processes. The paper may serve as a guide for the use of meteorological models to assess microclimatic impacts of planned development projects, contributing to urban planning and adaptation strategies. [ABSTRACT FROM AUTHOR]

This paper aims to explore gender differences in thermal comfort under coupled environmental factors, as previous studies have primarily focused on air temperature alone. The experiment involved 27 subjects, 13 males and 14 females, who experienced 12 different combinations of air temperature and air velocity environmental conditions. The subjective responses and physiological parameters were collected and analyzed. In colder environments, especially when low air temperatures are coupled with elevated air velocity, significant gender differences are observed, as females feel colder, more uncomfortable, and perceive stronger drafts than males. In hotter environments, when high air temperatures are coupled with still air, males tend to feel more uncomfortable and prefer higher air velocity, compared to females. However, few gender differences are observed when high air temperatures are coupled with elevated air velocity. Under colder conditions, forearm temperatures show a stronger correlation with subjective responses, while under hotter conditions, facial skin temperatures demonstrate a stronger correlation, for both genders. Moreover, the Elevated Air Speed Model in ASHRAE 55–2020 is found to overestimates the cooling effect of elevated air velocity for both genders. The findings suggest that gender differences should be properly considered when designing indoor thermal environments, particularly under colder conditions. [ABSTRACT FROM AUTHOR]

An excellent way to obtain a detailed description of the air flows and temperature field in a zone is to perform accurate Computational Fluid Dynamics (CFD) simulations. Unfortunately, this is often prohibitive due to the powerful resources that are required, and the large computational times. As a consequence, several intermediate models between CFD and the standard well-mixed models have been proposed over the years. These are known as zonal models, and they aim at delivering sufficiently accurate predictions of the thermal comfort in a room, for long periods (months or even years), and with substantially shorter computational times. However, none of these models has yet been implemented in a building performance simulation (BPS) tool. In this work, we have developed and implemented a BLOCK zonal model [1,2] within the IDA ICE (BPS) software. A multi-node 1D model for the prediction of vertical temperature gradients is used, together with flow element theory and an appropriate algorithm for the estimation of view-factors in non-convex geometries with obstacles. The paper presents the theoretical background of the model along with advice on its range of applicability. Finally, the model is validated against several test cases, showing its suitability in predicting the thermal stratification. [ABSTRACT FROM AUTHOR]

[Display omitted] • High resolution data from a Dutch net zero energy neighborhood is analysed. • Most buildings are positive energy, emit less carbon than they offset. • Large occupant differences in energy demand are visible across the households. • Occupant preferences and weather conditions greatly influence thermal energy demand. • Due to the high thermal efficiency, there is a high risk for summer overheating. Decarbonizing the building stock is a central component of global climate change mitigation efforts. In practice, this decarbonization can be achieved by a variety of different measures, including improvements in building energy efficiency, electrification of energy demand to reduce reliance on fossil fuels, and installation of distributed (renewable) generation in conjunction with flexible storage. However, these large-scale, often disruptive changes to the built environment also raise a number of concerns, such as loss of occupant comfort exacerbated by climate change, and introduction of additional stressors on the distribution grid. In this paper, we demonstrate several conclusions using detailed sub-hourly data of two years (2019–2020) collected from 40 homes in a recently refurbished net-zero energy neighborhood in the Netherlands. This paper shows that, in renovation projects like the case study, net-zero energy balances should be considered on a neighborhood, rather than building level to minimize worst case planning by accounting for occupant influences and seasonal effects. Furthermore, the energy flexibility and climate resilience in the buildings seems to be rather limited, as a result of energy efficiency improvements. While helpful in climate change mitigation efforts, the large seasonal differences in energy demand and generation imply that this evolution is perhaps sub-optimal from the grid perspective. The results illustrate that all homes in the study were net-zero energy over the two year period, sometimes net positive by up to a factor of three. This led to considerable excess generation especially during the summer months. In addition, it was found that indoor air temperature sensors in a number of buildings showed overheating beyond guideline thermal comfort temperature of 25°C, showing potential thermal comfort and heat stress for vulnerable occupants. These results motivate energy storage or modifications of the installed heat pumps to leverage summer excess generation while reducing the impact of summer heat waves. These findings should enable the Netherlands and other countries aiming to fully decarbonize the building stock formulate better, future-proof policies. [ABSTRACT FROM AUTHOR]

In HVAC systems, the application of fault detection and diagnosis (FDD) for chillers has brought many benefits to building utilities, i.e., indoor thermal comfort, energy saving, and energy consumption management. Although recent studies have achieved great progress on chiller fault diagnostic problem, some serious issues have been raised in these studies and need to be resolved comprehensively. In that context, two problems are listed and studied in this paper namely outliers detection and the insufficiency of labeled data. To deal with outliers mixed in chiller data, this paper proposes a supervised multiclass deep autoencoding Gaussian mixture model (S-DAGMM) algorithm which is an ensemble model of individual unsupervised DAGMMs. This mechanism helps S-DAGMM to detect ambiguous outliers in both training and testing data. In addition, this paper proposes to use DAGMM to pretrain a deep neural network (DNN). Since DAGMM can learn the data distribution from the unlabeled data, it can prevent DNN from getting stuck on local optima. Comprehensive experimental results in this study have proved the outstanding performance of the proposed approach, compared with state-of-the-art rival methods. [ABSTRACT FROM AUTHOR]

This paper evaluates through experimental testing a prototype of switchable insulated shading (SIS) systems suitable for windows to optimize solar heat gains in order to maintain indoor thermal comfort. Specifically, the paper describes a laboratory testing procedure and measurement results for SHGC values specific to various SIS designs and operation settings using a box calorimeter set-up. The SIS prototype can modulate continuously its optical and thermal properties including U-value and SHGC using rotating insulation layers controlled through an actuator to a specific slate angle setting. The results of the experimental testing confirm that SHGC value for the SIS prototype is correlated to the slate angle of the insulated layers. This correlation remains applicable for any SIS insulation thickness. The measured data are used to assess the potential energy efficiency benefits from SIS when applied to windows for US homes. In particular, a prototypical housing unit located in three US cities is considered to evaluate the energy efficiency potential for switchable opaque insulated shading systems. The results indicate that SIS systems can achieve up to 8.3%, 11.3%, and 11.4% in annual HVAC energy consumption compared to no-shading cases for dwellings located in Golden, CO (representing a cold climate), Phoenix, AZ (representing a hot climate), and San Francisco, CA (representing a mild climate), respectively. [ABSTRACT FROM AUTHOR]

• Tangible device for thermal comfort and indoor air quality feedback was studied. • The device was suitable for collecting feedback on thermal comfort and complaints. • It could support the operation manager to monitor and improve building performance. • I.a. identifying poorly set indoor temperature setpoints. • I.a. identifying control strategies for HVAC resulting in an energy saving of 46%. Smartphone applications or electronic devices in the form of occupant voting systems (OVS) have demonstrated to be feasible for acquiring feedback from occupants to support the building operation manager to identify indoor environmental quality (IEQ) problems and inappropriate control settings of heating, ventilation and air-conditioning (HVAC). The present paper aims to contribute to the growing research on OVS as a tool to support building operation management. The paper presents a study about a tangible OVS, denoted TiAQ, that occupants could use to vote on their here-and-now experiences regarding the thermal environment and indoor air quality. The main objectives were to identify whether there was an alignment between the votes collected with TiAQ and the monitored IEQ variables as well as to demonstrate the use of occupant votes to identify problematic IEQ conditions and appropriate strategies for HVAC control. The study demonstrated that thermal votes collected with TiAQ could be related to the variations in the indoor temperature and ventilation airflow. Additionally, collected votes could identify i.a. poorly set indoor temperature setpoint and appropriate control strategies that could reduce energy use by 46% and increase thermal comfort and cold complaints by 6% if current airflow and indoor temperature setpoint were lowered. [ABSTRACT FROM AUTHOR]

• Computational Fluid Dynamics model is employed to study HVAC performance. • Study focuses on investigation of dynamic effects with on/off HVAC operation. • Even with constant outdoor temperature, duration of HVAC cycles varies markedly. • Computed variability of cycle durations agrees well with field data. • Turbulent fluctuations of an interior air temperature are a source of variability. This paper investigates an influence of an intermittent on/off operation of the air-conditioning (AC) equipment on the indoor temperature distribution, air flow and a cycle variability within a single-floor medium-size residential house. The analysis is performed using a recently developed and well validated computational tool based on a Computational Fluid Dynamics (CFD) method, coupled with conjugate heat transfer simulations within a three-dimensional model of a solid building envelope, and an HVAC on/off control model. The importance of including unsteady minute-level dynamic effects associated with the cycling of AC equipment into the energy and thermal analysis of residential and commercial buildings was recently recognized. Despite that, there were no studies that examined the effect of on/off cycling on the physics of the air mixing during both cooling and heating stages of the AC cycle, and how these unsteady interactions effect both the energy consumption and its variability, and the indoor thermal environment linked to a thermal comfort of the building occupants. The current paper focuses on analyzing the duration and variability of the cooling and heating cycles and their effect on the temperature distribution inside a residential house. It is found that both heat transfer from the walls, and turbulent intermittency of the indoor air affect the duration of the cooling and heating cycles. It is demonstrated that a central air system controlled by a single thermostat placed in the hallway results in a consistent overcooling of the interior spaces. These findings are important for the considerations of the electric grid management, and for the improvement of HVAC systems design and control. [ABSTRACT FROM AUTHOR]

[Display omitted] • Impacts of reverse cycle air-conditioners (RCACs) during summer are examined. • Wellbeing impacts are studied via a survey of 283 Australian public housing tenants. • Positive and significant impacts on measures of health and housing suitability are found. • Households with RCACs increased summertime electricity expenditure by about A$40. • There is no significant impact on subjective reporting of energy bill stress. Heating and cooling upgrades can have important implications for energy bills and thermal comfort in public housing. However, more could be known about the specific impacts of such upgrades, including on tenant wellbeing. This paper examines upgrades delivered to public housing properties in the Australian Capital Territory, focusing on effects in summer. We analyze impacts of replacing existing heaters with energy-efficient reverse cycle air-conditioners (RCACs). The principal research question is: by how much does access to indoor cooling increase wellbeing among public housing tenants? The analysis is based on a survey of 283 residents carried out in March–April 2021. We use factor analysis followed by linear regressions and an instrumental variable approach. Positive and significant impacts are found on measures of health and housing suitability, including the reported ability of residents to concentrate. Households with RCACs increased their summertime electricity bills by around A$40 relative to control households, although we find no significant impact on subjective reporting of energy bill stress. The study is among the first to apply rigorous econometric techniques to examine causal impacts of indoor cooling in residential settings. [ABSTRACT FROM AUTHOR]

• Households change their heating patterns when they switch to a heat pump. • Typically, a setback temperature 2–5 °C lower than the desired thermostat setting. • We calculate the increase in heat demand with varied parameters. • The increase in heat demand is determined by heat loss and thermal mass. • This would be a useful metric for 'heat pump readiness'. Heating with air source heat pumps is an important step in the transition to Net Zero Carbon for many households. When predicting the resulting energy consumption it is frequently assumed that heating demand is unchanged from before the switch from gas heating. However, heating patterns usually change, with a net increase in heating demand to achieve the same level of thermal comfort. This paper discusses the change in pattern and uses modelling to determine the resulting increase in energy demand. It shows that the increase can be predicted with information about dwelling heat loss and thermal mass as well as weather and the pre and post switch heating pattern. The increase can be 20% or more for homes with high heat loss. It proposes that the metric for heating demand increase would be a useful measure of heat pump readiness, and that the parameters required to assess this should be provided on energy performance certificates. [ABSTRACT FROM AUTHOR]

Providing the occupants with tailored feedback on their energy consumptions can be an effective method to help the users to adopt energy-efficient behaviours. However, in specific contexts such as the social housing, this may be challenging, due to the peculiarities and the economic constraints of the end-users, which make them vulnerable and needing a proper design of the information. Nevertheless, there is a lack of detailed studies in the literature analysing the effects of personalized energy feedback on the space heating consumption and the indoor air temperatures in the social housing sector. This paper aims to evaluate the effects on space heating consumption and indoor air temperature of a personalized feedback campaign delivered in three social housing buildings consisting of 27 apartments in Mediterranean climate. To this end, a personalized feedback campaign was designed and developed, providing for the use of disaggregated energy consumption indicators to show the location of excessive thermal energy consumptions. The daily thermal energy consumptions, as well as the indoor air temperatures of the single dwellings, were monitored daily for over four heating seasons and their variations were analysed before and after the implementation of the personalized feedback. A saving in normalized natural gas consumption of the buildings was found on average equal to −14,8% after the feedback campaign, with no significant variations in the indoor air temperatures. However, some critical issues have been highlighted in the response of individual end-users to the feedback provided. A greater propensity of the occupants to regulate the indoor air temperature through the thermostatic radiator valves in the unoccupied rooms of the house was also observed after the occurrence of the feedback campaign. [ABSTRACT FROM AUTHOR]

A microalgae-based biofacade is a double-skin facade with integrated photobioreactors (PBRs) for solar cultivation of microalgae. One purpose of cultivating microalgae on building facades is to create an 'active' facade that can reduce the energy consumption required to maintain thermal comfort inside the building, by creating exchange loops between the building and the microalgae cultivation system. This paper describes the experimental validation of a thermal model of a building equipped with a biofacade PBR, and its use in analyzing the energy consumption of international-standard buildings in two different climate conditions (oceanic climate using the weather data from Nantes, France, and semi-arid climate using weather data from Los Angeles, USA). The results of this analysis show that the microalgae biofacade almost entirely removes the building's cooling demand, and the warmer the location the stronger the effect. In addition, the heating demand of the biofacade PBR is also greatly reduced (between 92% and 100% depending on the location). The microalgae biofacade is therefore a more sustainable solution to produce valuable biomass and a promising technology for the development of zero-emission buildings; to this end, suggestions for optimizing the process are put forward. [ABSTRACT FROM AUTHOR]

According to WHO (World Health Organization) data, people spend at least 80% of their lives indoors, with the percentage rising to 95% for older people with mobility impairments. Creating a thermally comfortable indoor environment is essential for improving users' productivity and well-being, particularly for those who spend maximum time indoors, such as elderly people. India's ageing population is increasing significantly; however, there is lack of studies in the field of thermal comfort for the elderly. The main aim of this paper is to determine the thermal comfort range of elderly people in residences of warm and humid climates during summers in India and to find out the adaptive actions opted by the elderly population to achieve thermal comfort. 740 responses were collected from elderly people through questionnaire surveys along with simultaneous field measurements during the summer. The linear regression analysis found the occupant's comfort temperature of 30 °C and the comfort range was found to be 28.5 °C- 31.5 °C, which was narrower than the younger people's thermal comfort studies at residences. The neutral temperature was higher for the male elderlies than the female elderlies, which was highly correlated with their clothing adjustments. The probit analysis revealed that 90% of the elderly felt comfortable when the operative temperature varied between 26.9 °C and 30.9 °C. Clothing adjustments and taking cold showers are the most preferred behavioural actions by the elderlies in summer, whereas changing the cooking time and tying up hair are the most preferred behavioural adaptations to overcome thermal discomfort for female elderlies. [ABSTRACT FROM AUTHOR]

Traditional Heating, Ventilation and Air-conditioning systems operate on a fixed schedule, regardless of occupancy or external temperature. With the rise of smart buildings, building managers and owners are seeking ways to reduce energy consumption while maintaining occupant comfort. There are various environmental and personal factors that impact thermal comfort levels. In this paper, we aim to develop a machine learning-based approach for precisely forecasting the thermal comfort levels of building occupants using the readily available ASHRAE RP-884 database. The dataset was first pre-processed using a k Nearest Neighbor (kNN)-based imputation method. Then, the RRelifF algorithm was used to select highly relevant and practically retrievable input features. Based on the selected features, four ensemble models were created to assess the relationship between input features and thermal comfort levels. A decision-making rule was employed to determine the credibility of each predictor, with only credible outputs selected. The credible outputs were aggregated to produce the final predicted mean vote (PMV) using Genetic Algorithm (GA) optimized coefficients. The testing results were promising, exhibiting high accuracy and a low Root Mean Squared Error (RMSE) value of 0.157 in the prediction of PMV. [ABSTRACT FROM AUTHOR]

• Analyzed residents' thermal demand characteristics under the global climate change. • A new thermal comfort evaluation model of traditional dwellings was established. • The new thermal neutral temperature and comfort range of residents were proposed. • Different measures to improve the old and new types of dwellings were put forward. Global climate change has led to increased differences in the indoor thermal environment of traditional dwellings and residents' thermal adaptability, but quantitative research in this area needs to be updated and improved. In this paper, taking the old and new types of traditional dwellings of Guangfu Ancient City in Hebei province, China as the example, we first investigated the current situation of indoor thermal environment and thermal comfort characteristics of residents by means of subjective questionnaire survey and objective data measurement. The measured data showed that the average indoor temperature of old-type traditional dwellings in winter was far lower than the thermal comfort range of human body, and it was also higher than the relevant standard in summer. Secondly, we established a new thermal comfort evaluation model of traditional dwellings and proposed a new thermal neutral temperature of residents: old-type traditional dwellings (18.1 °C in winter and 27.1 °C in summer), new-type traditional dwellings (19.8 °C in winter and 25.7 °C in summer). Although the measured data showed that the thermal environment quality of the old-type traditional dwellings was poor, the residents had strong thermal adaptability. Finally, we put forward the different living performance improvement strategies of old and new types of traditional dwellings: The old-type traditional dwellings should focus on strengthening the thermal performance of the envelope structure, while the new-type traditional dwellings should solve the problem of low indoor humidity in winter. This research improves the evaluation system of human thermal comfort of dwellings in cold region of China, and provides a good case reference. [ABSTRACT FROM AUTHOR]

• Genetic Algorithm (GA) based on Non-dominated Sorting Genetic Algorithm 2 (NSGA2) method is used for optimization. • Building optimization using passive design strategies can reduce final HVAC energy use 32% • Building optimization using passive design strategies can reduce time-integrated discomfort 46% • Overheating in nearly Zero Energy Buildings will be aggravated with continuation of global warming. • Building thermal comfort optimization does not ensure overheating mitigation during unprecedented events. It is expected that heatwaves will strike more frequently and with higher temperatures with the continuation of global warming. More extreme heatwaves concurrent with disruptions in the cooling system can lead to significant overheating problems in buildings affecting occupants' health, productivity, and comfort. This paper projects current and future heatwaves on an optimized nearly Zero-Energy terraced dwelling in Brussels, assuming the outage of the cooling system. Initially, a multi-objective optimization is performed considering 13 passive design strategies using the Genetic Algorithm (GA) based on the Non-dominated Sorting Genetic Algorithm 2 (NSGA-II) method. It is found that high ventilation rate, low infiltration rate, high insulation, high thermal mass, integration of green roof, and application of operable roller blinds are beneficial in reducing the final HVAC energy use up to 32% and enhancing thermal comfort up to 46%. Subsequently, three optimal solutions are selected and analyzed under the highest maximal temperature heatwaves detected during the 2001–2020, 2041–2060, and 2081–2100 periods. It is found that non of the optimal solutions are able to fully suppress overheating during heatwaves and the cooling system outage. The indoor operative temperatures reach more than 29 ° C , which can cause serious health issues for the occupants. The situation will be exacerbated in the future since an increase in maximum Heat Index (HI) between 0.28 °C and 0.49 °C, an increase in the maximum operative temperature between 1.34 ° C and 2.33 ° C , and a decrease in Thermal Autonomy (TA) between 17% and 28% are estimated. Finally, some recommendations are provided for practice and future research. [ABSTRACT FROM AUTHOR]

[Display omitted] • UHMA research are booming in publications, authors, institutions, and research areas. • UHMA has evolved into a transdisciplinary research field, covering many emerging areas, beyond the built environments. • UHMA research covers: (i) UHI impact assessment and cause identification, (ii) microclimate regulation and human thermal comfort, (iii) climate-related health impact and adaptation, and (iv) urban heat mitigation strategies and techniques. • This study highlights UHMA knowledge gaps in seven dimensions and UHMA development in five aspects. • This study proposes 13 suggestions for promoting the transformation from UHMA research to practice. This paper presents a bibliometric review of the history and evolution of Urban Heat Mitigation and Adaptation (UHMA) from 1989 to 2021 to identify its research progress, knowledge gaps, and future research directions. The results indicate that research on UHMA is booming and that the field has diversified over time. Existing studies have examined UHMA from the environmental, technical, health, economic, and social perspectives. Over time, UHMA has evolved into a transdisciplinary research field, covering many emerging areas beyond built environments, including materials, computer sciences, physiology, chemistry, and geosciences. Relevant UHMA topics can be divided into four research clusters: (i) UHI impact assessment and cause identification, (ii) microclimate regulation and human thermal comfort, (iii) climate-related health impact and adaptation, and (iv) urban heat mitigation strategies and techniques. This study highlights some knowledge gaps in UHMA research, including (i) overfocusing on urban heat causes, effects, and mitigation solutions; (ii) more focus on mitigation, overshadowing adaptation, and preparation; (iii) highlighting materials and vegetation, but overlooking water features and urban form; (iv) incomplete understanding of heat-related impacts; (v) focusing more on microclimate and heat islands rather than extreme heat; (vi) unsound policy, social, and economic support; and (vii) lack of actual UHMA implementation. There are also some challenges in UHMA development, including (i) the uneven distribution of publications, authors, and affiliations; (ii) topic, affiliation, and nation aggregation and bias; (iii) slow evolution in key disciplines, publications, and authors; (iv) knowledge isolation owing to tendentious academic collaboration and communication; and (v) limited journal scope and restricted methodological approaches. To overcome such challenges and enhance UHMA research and policy, 13 suggestions were made. Overall, by promoting transdisciplinary UHMA research informed by climatic sciences, scientific models, policy-relevant techniques, and socio-economic support, this study is expected to better frame UHMA research and bridge science and policy. [ABSTRACT FROM AUTHOR]

The optimization of energy consumption in buildings' HVAC systems plays a crucial role in reducing greenhouse gas emissions worldwide. In new and deeply-renovated buildings, characterized by modulating terminal units and aiming at the maximum exploitation of renewables, an accurate hydraulic balance of the distribution network may become critical, resulting in a significant increase of pumping energy consumptions and a deterioration of indoor thermal comfort conditions. In the present paper, we compare the performance of traditional manual balancing valves and new pressure independent control valves (PICVs), used to balance the hydronic loop of HVAC systems. To perform this analysis, a new MATLAB-Simulink model has been specifically developed to simulate the behavior of PICVs and has been used in an application case study. The efficiency of manual and pressure independent control valves is evaluated numerically by simulating a multi-zone distribution network under variable operating conditions and considering different control strategies of the circulating pump. Results show that in off-design conditions, when some of the branches of the hydraulic network are closed, traditional manual balancing valves are not able to guarantee the nominal mass flow rate in the remaining loops. On the contrary, no significant variations of water mass flow rate are observed when PICVs are adopted, even in partial load conditions. Despite their additional cost, PICVs allow to ensure better indoor thermal comfort sensations for individuals, avoiding under/over-heating of rooms and, moreover, yield a decrease of the pump electric consumption with respect to traditional manual balancing valves. In addition, based on the obtained results, general rules concerning the adoption of PICVs are provided, depending on the extension of the hydraulic loop and the adopted pump control logic. The reported results highlight the role that PICVs can play to ensure energy savings in HVAC systems without penalizing users' indoor comfort conditions. [ABSTRACT FROM AUTHOR]

• Occupant' thermal responses with CC + MV or CC + UFAD were investigated. • Thermal environment was comfortable as operative temperature was 25.0 °C-27.0 °C. • Thermal neutral temperature with CC + MV was 0.4 °C −0.8 °C higher than CC + UFAD. • Thermal comfort stability of operative temperature differed from skin temperature. • Thermal responses correlated well with operative temperature or skin temperature. A radiant ceiling cooling (CC) system integrated with a mechanical ventilation system, which can improve human thermal comfort and reduce HVAC system energy consumption simultaneously, has been extensively applied in the modern office building with glass curtain walls. In a ceiling cooling room with a glass curtain wall, the horizontal and vertical asymmetric radiation caused by the warm wall and cool ceiling may result in different thermal responses of human body. Therefore in this paper, occupant's thermal responses in a simulated ceiling cooling office room with mixing ventilation (MV) or underfloor air distribution (UFAD) were investigated by a combination of subjective and objective experiments. Indoor operative temperature was increased from 23.0 °C to 30.0 °C as the surface temperatures of warm wall and cool ceiling were from 30.0 °C to 40.0 °C and from 14.0 °C to 27.0 °C. The results showed that the indoor thermal environment with CC + MV or CC + UFAD was comfortable and acceptable as the indoor operative temperature was from 25.0 °C to 27.0 °C. The thermal neutral operative temperature in the room was 25.6 °C with CC + MV and 26.4 °C with CC + UFAD, and the corresponding thermal neutral skin temperatures was 33.4 °C and 33.7 °C, respectively. Moreover, the thermal comfort stability of indoor operative temperature was close to 0.30 °C−1 with CC + MV or CC + UFAD, and the corresponding thermal comfort stability of mean skin temperature was 0.90 °C−1–0.94 °C−1. There were clearly linear relationships between thermal sensation or thermal preference and indoor operative temperature or mean skin temperature, and these relationships may be beneficial for the intelligent control of a radiant ceiling cooling system combined with a mechanical ventilation system. [ABSTRACT FROM AUTHOR]

• Provided a platform to test various residential building control systems. • Used probability of occupancy to determine setback temperature when unoccupied. • Integrated optimizer with adaptive and occupancy control. • Generated dynamic electricity tariff based on wholesale electricity pricing. • Evaluated the peak load shaving potential with dynamic pricing and optimization. Energy consumption in buildings continues to rise with increased deployment of energy-consuming equipment such as Heating, Ventilation, and Air Conditioning (HVAC) amid a growing world economy. Renewable energy is projected to comprise a majority of the future electricity supply, but the intermittent nature of renewables means that consumption must respond to dynamic supply for optimal utilization. This paper proposes a novel HVAC control strategy for residential buildings using the adaptive comfort model, considering occupancy through probability and real-time information, and optimizing the HVAC schedule to reduce cost, maintain thermal comfort, and respond to the dynamic availability of renewable energy while being generalizable to different situations. To validate this approach, the Universal CPS Environment for Federation (UCEF) co-simulation platform is used to connect advanced building controls with the building energy simulation software EnergyPlus. Simulations are performed for a residential building in Sacramento, CA during a typical summer week. Economic impacts, energy consumption, and thermal comfort are analyzed for traditional, adaptive, and occupancy-based control strategies under demand-based, tiered, and fixed electric tariff systems. Simulation results show that occupancy consideration, adaptive thermal comfort, and optimization can reduce cost by 50.1 %, electricity consumption by 52.9 %, and discomfort by 56.2 % compared to traditional fixed setpoints. The ability of the proposed HVAC control strategy to shift energy consumption away from peak times under a demand-based tariff system is qualitatively analyzed and findings suggest that maximum load-shifting on a grid-scale is attained using occupancy consideration with optimized control and demand-based pricing. For individual residential buildings, similar economic benefits can be gained using the less-complex adaptive HVAC control strategy with existing tiered or simple electric tariff systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Real-time identification of occupancy and window opening using AI-powered cameras. • Occupant-centric control strategy for better thermal comfort, energy efficiency and air quality. • The heating energy consumption was reduced by between 0.6 % and 29.0 %. • The level of indoor thermal comfort increased by up to 58.8 %. • Indoor CO 2 concentrations below 1000 ppm for 89.2 % of the time being occupied. Recently, Occupant-Centric Control (OCC) strategies have gained mounting interest. Previous studies made use of OCC strategies for adjusting the operation of heating/cooling systems, improving indoor thermal comfort and governing mechanical ventilation systems. However, a very limited number of studies have applied OCC strategies to natural ventilation systems. Further, the feasibility of establishing OCC strategies for controlling indoor thermal comfort, energy use and specifically air quality has received much less attention and investigation. This paper presented an Occupant-Centric Heating and Natural Ventilation Control (OCHNVC) strategy for enhancing indoor thermal comfort, building energy performance and indoor air quality. Firstly, real-time profiles of occupant behavior and window opening in a case study building were collected using artificial intelligence (AI)-powered cameras and deep vision algorithms. Secondly, shallow artificial-neural-networks predictive models were established for forecasting the responses of the studied building to different levels of occupant behavior and window opening behavior. Thirdly, an OCHNVC strategy tailored to the studied room was proposed and applied to the studied room. The strategy could lower heating energy consumption by between 0.6 % and 29.0 % and improve the level of indoor thermal comfort by between 0 % and 58.8 %, relative to a conventional control strategy. Moreover, the conventional window control strategy only maintained indoor CO 2 concentrations below 1000 ppm for 59.7 % of the period that occupants were within the studied room, while the proposed controller could do so for 89.2 % of the period. Future works shall focus on experimentally deploying the strategy to real buildings and evaluating its performance. [ABSTRACT FROM AUTHOR]