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• A simple, large-scale fabrication of cooling paper via pulping and papermaking technology. • The cooling paper is facilely deconstructed and regenerated to architect the secondary cooler. • The cooling paper features a high solar reflectance of 94% and emissivity of 0.95. • The cooling paper shows the sub-ambient temperature drop of 6 ∼ 8.8 °C under directly solar radiation at daytime. Passive radiative cooling materials provide coldness without energy consumption for all-day thermal comfort by reflecting solar irradiation and emitting heat into the 3 K universe. However, the conventional radiative cooling materials involve complex multilayer structures and unsustainable polymers, showing the non-recyclable disadvantage, which induces resource waste and environmental issues. Herein, we reported a low-cost, scalable, and eco-friendly radiative cooling material (namely cooling paper), consisting of the delignified, fibrillated cellulose fibers and nano-sized hydroxyapatite (HA) via the mature pulping and papermaking process. The resulting cooled paper can be recycled, and it can be easily deconstructed to harvest cellulose fibers and HA, individually. The recovered source materials can be reused to prepare secondary products that show comparable performance to the original cooling paper, including a high solar reflectance of ∼94% and an infrared emissivity of ∼0.95 in the atmospheric transparency window. Such cooling paper enables superior cooling performance with the temperature drop of 6 ∼ 8.8 °C under directly solar radiation. Based on the EnergyPlus simulation, our cooling paper shows a average cooling energy saving of ∼29 % in buildings across China. The recyclable cooling paper with high cooling capability and scalability, as well as environmental friendliness, shows promising potential for sustainable energy-efficient buildings. [ABSTRACT FROM AUTHOR]

Mixed-mode ventilation system (MMVS) can significantly decrease the energy consumption of Egyptian office buildings while meeting indoor air quality requirements and thermal comfort of occupancy. This paper studies the effect of using mixed-mode ventilation system (MMVS) in achieving both energy efficiency and thermal comfort in office buildings. The research specifically focuses on investigating the energy-saving potential and thermal performance of existing office buildings in Egypt by merging natural ventilation (NV) with mechanical ventilation (MV) to reach an effective mixed-mode ventilation system (MMVS). Additionally, an energy performance simulation was used to study how to achieve thermal comfort and the building's indoor temperature. Firstly, a selected office building in Cairo was used as a case study, and its thermal performance was studied by simulation. Secondly, site measurements were conducted to record the real thermal performance of the tested office building. These measurements were used for the validation phase. The validation demonstrated a satisfactory agreement between the building simulation and measurement data for air temperature (T) and relative humidity (RH). Thirdly, building energy simulations and analysis were used for testing the energy performance and thermal comfort of the tested scenarios that have different alternatives in the operation settings. The results revealed that it is possible to increase the thermal comfort hours by merging natural ventilation and applying the mixed-mode ventilation system only by changing the operation settings on the MMVS performance. The building's annual energy consumption was reduced by approximately 27 % compared with the use of HVAC in the building. Natural Ventilation hours increased by approximately 27 % to reach 427 hours (h) and the HVAC hours decreased by 17 % to reach 898 hours (h). [ABSTRACT FROM AUTHOR]

Museums environment is complicated and defined by indoor air quality, thermal and lighting comfort. Artifacts deterioration is factored by extreme conditions of thermal exposure or excessive lighting. With high control required for exposed old monuments and visitor comfort, museums energy systems reach extreme levels. In this paper, we aim to find the gap in museums high energy loads and reach solutions through architectural design. The paper studies comparison results for different techniques in fifty recent case studies to identify the specific factors that matter most to museum buildings. These factors are implemented simultaneously on one base model in three climatic states by multi-objective optimization. The best option will showcase each climate optimum conditions. The paper introduces optimum architectural procedures optimizing sDA and ASE to minimum 70% and maximum 10% respectively while decreasing thermal load. The results help architects and policy makers achieve daylighting and energy optimization in museums through architecture. [ABSTRACT FROM AUTHOR]

The rapid development of urbanization in China inevitably leads to a sharp increase in building energy consumption, and Passive House (PH) have received much attention in China in recent years. In this paper, the annual energy demand (AED) and summer discomfort hours (SUH) of PH are used as optimization objectives to establish a set of design solutions for multi-objective optimization (MTO) and economic analysis of a PH in Shandong Province, China. It is found that (1) the algorithm based on nearest neighbor component analysis (NCA) feature extraction applies to the sensitivity analysis of multivariate nonlinear high-dimensional data, and the NCA-GA-RBF neural network technique is proposed, which has significantly improved the goodness of fit and generalization ability for AED and SUH. (2) The NSGA-II genetic algorithm is used for the optimization search, and the results show that the overall improvement rates of AED and SUH are 25.5% and 21.6%, respectively, among the nine solutions after comprehensive evaluation; (3) Finally, the optimal scheme of energy saving and the optimal scheme of the economy are selected for economic evaluation. By comparing the economics of the two options and the improvement rates of AEDs and SUHs, the guidelines for design decision-makers are provided. In summary, the design scheme of this paper is forward-looking and reference-oriented and provides some reference suggestions for the development of PH in China. • The NCA algorithm is suitable for multivariate nonlinear sensitivity analysis. • NCA-GA-RBF has stronger and more stable generalization ability and accuracy. • In this paper, climate is the main factor affecting thermal parameters. • Global costs have a stronger economic interpretation. [ABSTRACT FROM AUTHOR]

The construction industry's excessive energy usage necessitates practical solutions to address this pressing issue. Windows are crucial architectural elements as they allow the majority of natural light to enter a structure. The poorly designed window and related components cause the space to overheat, consuming more energy. However, it negatively impacts the building's thermal and visual comfort. The paper introduces a novel approach for optimizing control parameters for egg shadings through multi-objective methods. The recommended approach significantly reduces the building's energy consumption and enhances its thermal and visual comfort. EnergyPlus is a software utilized for conducting energy-related simulations. The JEPLUS software has therefore considered seven design variables, such as differences in the vertical and horizontal angles of the shade, length and horizontal dimensions, depth and vertical dimensions, and window positioning. These year-round simulations are performed in four different orientations for four different Iranian towns with various climates. The data is improved by using the program JEPLUS + EA. To find the best locations on the Pareto front, the data is optimized using the NSGA-II approach. The optimization results indicate that a lower angle improves visual comfort but takes more electricity for lighting. The findings of multi-objective optimization of controlled blind characteristics improved thermal and visual comfort with ranges of 5–45% and 55–100%, respectively, and lowered overall building energy consumption by 1–19% yearly, depending on the building's geographic orientation. [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]

• 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 provides a review of the literature concerning the impact of temporarily increased cooling setpoint temperature on occupant thermal comfort during demand response (DR) events in commercial, air-conditioned buildings. We address concerns regarding thermal comfort as it relates to zone temperature modifications that may be implemented as a part of DR measures. Increased zone setpoint temperatures during the cooling season can adversely affect building occupants physically and psychologically, and impair their perceived indoor air quality and self-estimated performance. In some cases, however, improved occupant thermal comfort due to warmer zone setpoint temperatures during DR events has also been reported. In order to reduce the negative impacts on building occupants, DR must be implemented with careful control and monitoring. There are significant differences in assumptions made about the way people would respond to a thermal environment between the static heat balance model and the adaptive approach, with the adaptive approach offering a wider range of acceptable indoor temperatures. Therefore, application of the adaptive approach could be one option to improve building energy performance by taking advantage of occupant adaptive behaviors during DR events. Depending on the building services and systems available, expectations of the occupants, and the control options they are given to adjust to their thermal environment, occupants could potentially adapt to temperatures higher than what are currently being practiced in buildings. However, an upper limit threshold for temperature modifications, even if temporary ones, must be recognized to minimize adverse impacts on building occupants prior to DR implementation. Therefore, the ideal goal would be to develop menthods that would identify an optimum balance between energy consumption and the building occupant thermal comfort before applying DR strategies. Prior review papers relevant to DR have generally concentrated on the energy saving potential alone, or where energy savings have been prioritized over occupant thermal comfort. This paper reviews implementation of DR from the perspective of occupant thermal comfort and presents a summary of the most relevant experimental and field studies regarding occupant thermal comfort during DR events in commercial, air-conditioned buildings. [ABSTRACT FROM AUTHOR]

The objective of this paper is to optimize the passive design of newly-built residential buildings in hot summer and cold winter region of China for improving indoor thermal comfort while reducing building energy demand. In this respect, this paper investigates the performance of a representative apartment building in the city of Shanghai and evaluates the optimum solutions by using a developed optimization approach, which includes three major steps of 1) setting the model for multi-objective optimization, 2) sensitivity analysis for reducing the dimension of input variables, and 3) multi-objective optimization by using the Non-dominated Sorting Genetic Algorithm II (NSGA-II) coupled with the Artificial Neural Network (ANN), among which a novel indicator for evaluating the annual indoor thermal comfort of residential buildings of Shanghai named Comfort Time Ratio (CTR) is defined based on the modification of Szokolay’s theory in terms of bioclimatic analysis, and the impacts of passive design variables on the indoor thermal comfort and building energy demand in terms of different directions are comprehensively investigated. Results of the multi-objective optimization indicate that the residential buildings of Shanghai have a great potential in comfort-improvement and energy-saving. A series of novel optimal passive design tactics for residential buildings in Shanghai are derived accordingly which could be easily understood and conveniently carried out by the architects in practice. [ABSTRACT FROM AUTHOR]

Peak load shaving is a very important issue, however, most of peak load shaving methods either require extra investments or reduce the comfort of the consumers. This paper analyzes the impact of circulating pumps of residential swimming pools on the peak load, and shows that shifting the active time of circulating pumps of residential swimming pools could shave the peak load without requiring extra investments or reducing the comfort of the consumers. First, based on an extensive dataset containing hourly energy consumption readings of 1005 residents during March 2011 and October 2012 in South Ontario, this paper analyzes the features of the energy consumptions of residents with and without swimming pools. Second, this paper proposes a novel non-intrusive appliance load monitoring method to estimate the energy consumption of circulating pumps of residential swimming pools. The advantages of the proposed method are that, compared with other non-intrusive appliance load monitoring methods, it does not require high sampling rate data or prior information of the appliance, therefore the cost of implementation is reduced and users’ privacy is protected. Finally, this paper shows that, the average hourly energy consumption of CPRSP is 0.7429 kW h. During the peak hour, circulating pumps of residential swimming pools contributes 20.11% energy consumption of residents with swimming pools, as well as 8.79% peak load of all neighborhoods. When considering minimizing the peak load, by postponing circulating pumps of residential swimming pools for 8 h rather than turn them off, the peak load can be shaved by 4.64%. When considering minimizing the cost of circulating pumps of residential swimming pools, the peak load can be shaved by 3.15% by postponing circulating pumps of residential swimming pools for 6 h, meanwhile the peak hour is postponed from 18:00 to 19:00. [ABSTRACT FROM AUTHOR]

In a traditional building design process (TDP), design variables are fixed sequentially, as opposed to integrated design process (IDP) which tends to avoid sequential design phases to create more sustainable buildings. First, a reference building is introduced and an energy model based on TRNSYS is presented to determine the energy consumption and comfort in the building. The model is validated based on energy bills, certified simulations and literature. Then, the paper performs an extended sensitivity analysis (SA) of 30 design variables with respect to different performance criteria related to energy consumption and comfort, based on a TRNSYS model. Three SA techniques were used, namely standard regression coefficients (SRC), partial rank correlation coefficients (PRCC) and Sobol indices. Results show that all three techniques yielded a similar ranking of the importance of the variables for most model outputs. Interactions between variables were identified with second-order Sobol indices. In the second part of this paper, a traditional design framework was adopted in which sets of variables were fixed sequentially. A SA was performed at each phase of the process, assuming fixed values for parameters chosen in previous design phases. Results show that fixing variables during the phases of a traditional design process tends to reduce the probabilities of finding low-energy consumption designs. Moreover, the influence of some variables was found to change during the design phases. [ABSTRACT FROM AUTHOR]

In times of great transition of the European construction sector to energy efficient and nearly zero energy buildings (nZEB), a market observation containing qualitative and quantitative indications should help to fill out some of the current gaps concerning the EU 2020 carbon targets. Next to the economic challenges, there are equally important factors that hinder renovating the existing residential building stock and adding newly constructed high performance buildings. Under these circumstances this paper summarises the findings of a cross-comparative study of the societal and technical barriers of nZEB implementation in 7 Southern European countries. The study analyses the present situation and provides an overview on future prospects for nZEB in Southern Europe. The result presents an overview of challenges and provides recommendations based on available empirical evidence to further lower those barriers in the European construction sector. The paper finds that the most Southern European countries are poorly prepared for nZEB implementation and especially to the challenge/opportunity of retrofitting existing buildings. Creating a common approach to further develop nZEB targets, concepts and definitions in synergy with the climatic, societal and technical state of progress in Southern Europe is essential. The paper provides recommendations for actions to shift the identified gaps into opportunities for future development of climate adaptive high performance buildings. [ABSTRACT FROM AUTHOR]

Modern cities and their architectural structures undergo significant functional and physical changes. In recent years, the interventions on building envelopes have increased. Therefore, it is necessary to analyse potential remodeling of glass facades, along with applying the concept of smart technologies, in order to increase energy efficiency of the existing buildings. This paper analyses the modernization process of devastated glass façade of the tall Slavija hotel, built in 1960s in Belgrade, Serbia, taking into consideration some positive examples of transformation and reskinning of buildings, where the aspect of medialization is an active part of urban renewal. The subject of this paper is the analysis of research findings about the improved thermal comfort of this building, after performing the replacement of its glass façade and converting the hotel building into an office building. Special attention was paid to the implementation of media technologies and final effects on energy balance of the newly designed facade. The proposed solution is supposed to evaluate the improved thermal comfort that was achieved by a radical renovation of the facade and by replacing the existing facade with a new single façade (double and triple glazed units), with media elements as well as without them. The research results are presented as proposals for improving EE public buildings by implementing the latest system of curtain walls in order to increase the value of the buildings. One of the most important criteria included in the process of energy refurbishment is technological improvement of the existing buildings, along with the presentation of media facades. The case study is based on EnergyPlus simulations. [ABSTRACT FROM AUTHOR]

Operational faults are common in the heating, ventilating, and air conditioning (HVAC) systems of existing buildings, leading to a decrease in energy efficiency and occupant comfort. Various fault detection and diagnostic methods have been developed to identify and analyze HVAC operational faults at the component or subsystem level. However, current methods lack a holistic approach to predicting the overall impacts of faults at the building level—an approach that adequately addresses the coupling between various operational components, the synchronized effect between simultaneous faults, and the dynamic nature of fault severity. This study introduces the novel development of a fault-modeling feature in EnergyPlus which fills in the knowledge gap left by previous studies. This paper presents the design and implementation of the new feature in EnergyPlus and discusses in detail the fault-modeling challenges faced. The new fault-modeling feature enables EnergyPlus to quantify the impacts of faults on building energy use and occupant comfort, thus supporting the decision making of timely fault corrections. Including actual building operational faults in energy models also improves the accuracy of the baseline model, which is critical in the measurement and verification of retrofit or commissioning projects. As an example, EnergyPlus version 8.6 was used to investigate the impacts of a number of typical operational faults in an office building across several U.S. climate zones. The results demonstrate that the faults have significant impacts on building energy performance as well as on occupant thermal comfort. Finally, the paper introduces future development plans for EnergyPlus fault-modeling capability. [ABSTRACT FROM AUTHOR]

The building sector is one of the main consumers of energy. Therefore, heating and cooling concepts for renewable energy sources become increasingly important. For this purpose, low-temperature systems such as thermo-active building systems (TABS) are particularly suitable. This paper presents results of the use of a novel adaptive and predictive computation method, based on multiple linear regression (AMLR) for the control of TABS in a passive seminar building. Detailed comparisons are shown between the standard TABS and AMLR strategies over a period of nine months each. In addition to the reduction of thermal energy use by approx. 26% and a significant reduction of the TABS pump operation time, this paper focuses on investment savings in a passive seminar building through the use of the AMLR strategy. This includes the reduction of peak power of the chilled beams (auxiliary system) as well as a simplification of the TABS hydronic circuit and the saving of an external temperature sensor. The AMLR proves its practicality by learning from the historical building operation, by dealing with forecasting errors and it is easy to integrate into a building automation system. [ABSTRACT FROM AUTHOR]

There has been an increasing concern on thermal comfort in sleeping environments and its associated energy use in the past few years. To improve the thermal environment and to reduce energy use of air conditioning in bedrooms, applications of task/ambient air conditioning (TAC) systems were proposed and studied previously. It’s indicated that the TAC system can be well integrated with a bed. Due to the variation of the envelope heat gain in a bedroom during night, it is necessary to study the thermal environment inside a bedroom and the energy use of a TAC system for the bedroom at varying envelope thermal loads. Therefore, this paper reports on a numerical study on a TAC system applied to a bedroom with different envelope heat gains. The influences of envelope heat gain on energy consumption of the TAC system and the indoor thermal comfort were studied in this paper. The research results show that at supply air flow rate ( Q s ) of 50 l/s, energy consumption was increased from 47.78 W to 213.11 W, and the PMV value was increased from −1.69 to −1.29 with the increase in envelope heat gain from 3.11 W to 155.6 W. To make PMV equal to zero under different envelope heat gains, linear regression models between supply air parameters and PMV were built and solved. The obtained values form curves where PMV = 0 and give a guide for operation of the TAC system. It was found that the calculation of energy consumption on these curves depends only on envelope heat gain. [ABSTRACT FROM AUTHOR]

By measuring practical temperature and performing questionnaire surveys, this paper investigates the energy consumption and existing indoor thermal condition in rural residential buildings during heating season in severe cold areas in northeast of China. Research is conducted on the characteristics of heating and energy consumption in rural residential buildings in severe cold areas from heating system such as Chinese “kangs”, rustic heaters, stoves and heated walls. The main results in the paper can be summarized as follows: (1) The remarkable characteristic of thermal environment in rural residential buildings is the uneven distribution of temperature both in one room and in different rooms; (2) Installation of insulation layers can effectively improve indoor thermal environment; (3) Income level of rural residents is the main factor that influences indoor thermal environment; (4) The main ways of heating are Chinese “kangs”, rustic heaters, stoves and heated walls in rural residential buildings in severe cold areas. These factors and laws obtained can influence the energy consumption in rural residential buildings in heating season in severe cold areas in northeast of China. [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]

We study the problem of tuning the parameters of a room temperature controller to minimize its energy consumption, subject to the constraint that the daily cumulative thermal discomfort of the occupants is below a given threshold. We formulate it as an online constrained black-box optimization problem where, on each day, we observe some relevant environmental context and adaptively select the controller parameters. In this paper, we propose to use a data-driven P rimal- D ual C ontextual B ayesian O ptimization (PDCBO) approach to solve this problem. In a simulation case study on a single room, we apply our algorithm to tune the parameters of a Proportional Integral (PI) heating controller and the pre-heating time. Our results show that PDCBO can save up to 4.7% energy consumption compared to other state-of-the-art Bayesian optimization-based methods while keeping the daily thermal discomfort below the given tolerable threshold on average. Additionally, PDCBO can automatically track time-varying tolerable thresholds while existing methods fail to do so. We then study an alternative constrained tuning problem where we aim to minimize the thermal discomfort with a given energy budget. With this formulation, PDCBO reduces the average discomfort by up to 63% compared to state-of-the-art safe optimization methods while keeping the average daily energy consumption below the required threshold. [Display omitted] • A primal–dual contextual Bayesian optimization framework to tune building controllers is proposed. • It asymptotically achieves the optimal performance while satisfying constraints on average. • It saves up to 4.7% energy compared to alternatives, satisfying thermal comfort constraints on average. • Alternatively, it can reduce the thermal discomfort by 63% within a given energy budget. [ABSTRACT FROM AUTHOR]

Climate change and its consequences are of great concern. Buildings can be affected by climate change in different ways, such as changes in energy needs and thermal comfort. However, the challenge is to quantify and assess the uncertainties involved in future climate data as well as the relevant adoption strategies. The aim of this paper is to demonstrate potential energy consumption changes in high performance building construction systems in a changing climate. In this paper, current and future weather data of three time slices of 2020, 2050 and 2080 were used to simulate the performance of a simple building in Manchester and London using DesignBuilder software which employs Energy Plus as its calculation engine. Five of the most commonly used and high performance construction systems were examined in terms of energy consumption in this model and results are given. In general, this paper provides a useful methodology for simplification in design decision-making for current and future UK housing. It is observed that future climate scenarios do not have major effects in qualitative comparisons of construction systems. [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]

Hemp-based building envelopes have gained significant popularity in developed countries, and now the trend of constructing houses with hemp-clay blocks is spreading to developing countries like Morocco. Investigating the hygrothermal behavior of such structures under actual climate conditions is essential for advancing and promoting this sustainable practice. This paper presents an in-depth experimental characterization of a commercial hemp-clay brick that has been exposed to the outdoor environment for four years, in addition to field measurements on a building scale demonstration prototype. Additionally, the study simulates 17 representative cities to assess the hygrothermal performance and energy-saving potential in each of Morocco's six existing climate zones, using the EnergyPlus engine. The experimental campaign's findings demonstrate excellent indoor air temperature and relative humidity regulation within the hemp-clay wall building, leading to satisfactory levels of thermal comfort within hemp-clay wall buildings. This is attributed to the material's good thermal conductivity and excellent moisture buffering capacity (found to be 0.31 W/mK and 2.25 g/m2%RH), respectively). The energy simulation findings also point to significant energy savings, with cooling and heating energy reductions ranging from 27.7% to 47.5% and 33.7% to 79.8%, respectively, as compared to traditional Moroccan buildings. [Display omitted] • Experimental characterization of thermal conductivity, sorption isotherm, and moisture buffering capacity of hemp bricks. • Assessment of indoor thermal comfort and energy demand in a hemp-based building across 17 cities in Morocco. • Hemp-clay bricks demonstrated excellent humidity regulation with a moisture buffer capacity of 2.25 g/m2%RH. • Hemp-clay walls can achieve energy savings ranging from 27.7%–47.5% for cooling and 33.7%–79.8% for heating in Morocco. [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]

• 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]

[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]

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]

Abstract: Air conditioning is essential for maintaining thermal comfort in indoor environments, particularly for hot and humid climates. Today, air conditioning, comprising cooling and dehumidification, has become a necessity in commercial and residential buildings and industrial processes. It accounts for a major share of the energy consumption of a building or facility. In tropical climates, the energy consumed by heating, ventilation and air-conditioning (HVAC) can exceed 50% of the total energy consumption of a building. This significant figure is primarily due to the heavy duty placed on cooling technologies to remove both sensible and latent heat loads. Therefore, there is tremendous potential to improve the overall efficiency of the air-conditioning systems in buildings. Based on today’s practical technology for cooling, the major components of a chiller plant are (1) compressors, (2) cooling towers, (3) pumps (chilled and cooling water) and (4) fans in air handling units. They all consume mainly electricity to operate. When specifying the kW/Rton of a plant, there are two levels of monitoring cooling efficiency: (1) at the efficiency of the chiller machines or the compressors which consume a major amount of electricity; and (2) at the overall efficiency of cooling plants which include the cooling towers, pumps for moving coolant (chilled and cooling water) to all air-handling units. Pragmatically, a holistic approach is necessary towards achieving a low energy input per cooling achieved such as 0.6kW/Rton cooling or lower by considering all aspects of the cooling plant. In this paper, we present a review of recent innovative cooling technology and strategies that could potentially lower the kW/Rton of cooling systems – from the existing mean of 0.9kW/Rton towards 0.6kW/Rton or lower. The paper, broadly divided into three key sections (see Fig. 2), begins with a review of the recent novel devices that enhances the energy efficiency of cooling systems at the component level. This is followed by a review of innovative cooling systems designs that reduces energy use for air conditioning. Lastly, the paper presents recent developments in intelligent air-control strategies and smart chiller sequencing methodologies that reduce the primary energy utilization for cooling. The energy efficient cooling technology, innovative systems designs, and intelligent control strategies described in the paper have been recently researched or are on-going studies. Several have been implemented on a larger scale and, therefore, are examples of practical solutions that can be readily applied to suit specific needs. [Copyright &y& Elsevier]

Abstract: This paper presents the key factors methodology that supports energy managers in determining the optimal building operation strategy in relation to both energy consumption and thermal comfort. The methodology is supported by the utilization of calibrated building energy simulation models that match measured data gathered by an extensive measurement framework. Building management systems, do not allow energy managers to test the impact of changes in control settings of energy systems on energy consumption and thermal comfort. The proposed methodology and prototype tool chain enables energy managers to virtually develop and test the impact of proposed changes to the control settings in the building energy systems prior to their implementation in the physical building. The paper outlines the proposed methodology defining the underpinning concepts and illustrating the performance metrics required to capture the effect of different building operation strategies. A case study is discussed to demonstrate the application of the methodology. [Copyright &y& Elsevier]

Abstract: In this paper, an EnergyPlus model was used to simulate the operation of a novel integrated HVAC system. This system combines an underfloor air distribution system with a cooled radiant ceiling slab. A cooling tower supplies water to pre-cool the structural slabs during the night and early morning period. The paper compares the performance of this system to both a typical overhead system and a typical UFAD system in the cooling season for the Sacramento, California climate. When compared to the overhead system, the integrated UFAD/Radiant system shows a 22–23% reduction in total energy consumption during the peak cooling months (June to August) and a 31% reduction in peak hourly electricity demand. When compared to the UFAD system, these reductions are 21–22% and 24% respectively. An investigation of the simulation results showed that the integrated UFAD/Radiant system also improves occupant thermal comfort and reduces thermal decay issues in the underfloor plenum. [Copyright &y& Elsevier]

Thermal insulation has become essential, firstly to ensure the thermal comfort of the occupants and secondly to save energy and that's why we find more and more varieties of insulators (organic, inorganic and synthetic) in the Moroccan market, depending on the need when to make the right choice. This paper presents the theoretical part of a thermal and an energetic study of the envelop of a house located in the city of Marrakesh (Morocco), by using four types of insulators, that are mostly used in Moroccan markets, for different thicknesses to determine the most suitable insulator for Marrakech climate and its optimal thickness. The insulators studied are: Expanded Polystyrene, glass wool, rock wool and wood fiber. The numerical simulations were realized using the software of thermal dynamic simulation TRNSYS. The results show that for a thickness of 8 cm of the wood fiber insulator saves about 7% for heating and 14% for cooling loads. For temperatures, in January temperatures are higher by 0.26 °C, and in July are lower by 0.49 °C. [ABSTRACT FROM AUTHOR]

Highlights • Lack of a clear path in the fight against energy poverty across the European union. • Energy poverty related to the residential sector allows new solutions to be developed. • Current energy poverty indicators provide an incomplete analysis of vulnerability. Abstract The term energy poverty (EP), mostly used to capture problems related to an inadequate access to energy suppliers in developing countries, and that of fuel poverty (FP), commonly employed when households suffer from insufficient monetary resources to pay for their basic energy needs, are used interchangeably by many researchers. Energy poverty and/or fuel poverty are considered to be an indication of domestic energy deprivation or energy vulnerability and remain a global problem that has been accentuated in Europe due to the economic crisis. This work has made a comprehensive review of the current concepts and indicators of FP, and of current initiatives to tackle this issue, across Europe, thereby raising the discussion of how energy vulnerability factors fit FP situations: available infrastructure, energy efficiency, social and economic poverty, and wellbeing and health. In this context, the first weak spot of the FP indicators and initiatives analyzed is that most factors that influence the everyday activities of a household are not considered (comfort, health, and wellbeing), resulting in an incomplete analysis if these are used in an isolated way. This paper provides a multiple-indicator approach to understand an FP situation beyond its traditional definition, thereby establishing a starting point for the reflection of vulnerability in policy decisions and methodological implications. [ABSTRACT FROM AUTHOR]

Buildings are known for being great consumers of energy and for operating under On/Off and linear control strategies in common commercial packages. In order to reduce their energy footprints and to improve thermal comfort, new methodologies are needed to obtain better input profiles. This paper presents a detailed study of the implementation of a nonlinear model predictive control (NMPC) approach for a heating, ventilation, and air conditioning (HVAC) system. The HVAC system is modeled by an index-1 differential-algebraic system of equations, obtained from rigorous material and energy balances. The proposed NMPC algorithm was implemented in GAMS and compared with another approach from the literature. Similarly, the objective function is defined using one or more of the following criteria: (1) tracking of temperature and relative humidity set points; (2) maximization of thermal comfort; (3) minimization of energy consumption. To better represent the situation in a real application, the simulations include model-plant mismatch in parameters such as air infiltration into the building, the coefficient of the thermal exchange between the building and the exterior, and occupancy level. Additionally, simulations with random measurement noise have been performed. The results have shown that the proposed approach, in which the model is not linearized at any step, is able to reduce the energy consumption and maintain the Predicted Mean Vote (PMV) close to the desired set point, while the computation burden is only increased by one second per iteration, which is negligible in comparison with a sampling time of 10 min. [ABSTRACT FROM AUTHOR]

Abstract Epidemiological studies on the impact of outdoor temperature to human health have demonstrated the capability of humans to adapt to local climate. However, there is limited information on the association between indoor temperature and human health, despite people spending most of their time indoors. The problem stems from the lack of sufficient indoor temperature measurement in the population. To overcome this obstacle, this paper presents an indirect epidemiological approach to evaluate the impact of high indoor temperature on mortality. The relationships between indoor-outdoor temperatures in different climate zones identified in the literature were combined with the outdoor temperature-mortality curves of the same locations to obtain the local indoor minimum mortality temperatures (iMMT), the temperature at which mortality is lowest, which by implication is the temperature at which the population is most comfortable on average. We show that the iMMT varies and has a weak linear relationship with the distance to the equator, which provides evidence of human adaptation to local indoor temperatures. These findings reinforce the adaptive comfort theory, which states that people can adapt to local indoor environment and establish their thermal comfort. Recognising the human adaptability to local climate will direct flexible and optimized policy to protect public health against extreme temperature events. This will also help reduce energy consumption for regulating indoor temperature without compromising the occupants' health. Graphical abstract Image 1 Highlights • First study of indoor minimum mortality temperature (iMMT) in different climates. • iMMT of a city has an association with its distance to the equator. • Variation of iMMT indicates that people adapt to their local climates. • The finding supports the adaptive thermal comfort standard. • Energy could be saved by being adjusted to local climate rather than a universal standard. The estimated indoor minimum mortality temperatures are different from the outdoor minimum mortality temperatures but varied similarly across climate zones. [ABSTRACT FROM AUTHOR]

Abstract The main characteristic of an indirect evaporative cooler (IEC) is the high dependency on ambient air conditions. To ensure stable indoor temperature and provide better thermal comfort, proper control strategy is essential. However, very limited studies report the controller used in IEC. In this paper, a novel control scheme named high-low (H-L) is proposed for regenerative indirect evaporative cooler (RIEC). Under H-L control scheme, the fans would be switched between high speed and low speed rather than completely turned off. The H-L control adopts the multi-speed technology, providing energy saving potential compared with conventional on-off control and overcome the complexity and costly of variable speed technology. The annual performance of RIEC was simulated under H-L control based on the RIEC model and dynamic indoor heat and mass balance model. The influence of low speed to high speed ratio (L/H) is discussed in order to propose an optimal L/H by considering both the thermal comfort and annual energy consumption. The results show that the H-L control can provide stable indoor temperature and satisfactory thermal comfort with Predicted Mean Vote (PMV) in the range of -0.5 to 0.5 for 76.2% of time. The optimal L/H is found to be 0.25 to 0.33 because of high thermal comfort provided and lowest energy consumption. [ABSTRACT FROM AUTHOR]

Abstract: Heating, ventilation and air conditioning (HVAC) systems are the most energy consuming building services representing approximately half of the final energy use in the building sector and between one tenth and one fifth of the energy consumption in developed countries. Despite their significant energy use, there is a lack of a consistent and homogeneous framework to efficiently guide research and energy policies, mainly due to the complexity and variety of HVAC systems but also to insufficient rigour in their energy analysis. This paper reviews energy related aspects of HVAC systems with the aim of establishing a common ground for the analysis of their energy efficiency. The paper focuses on the map of energy flow to deliver thermal comfort: the HVAC energy chain. Our approach deals first with thermal comfort as the final service delivered to building occupants. Secondly, conditioned spaces are examined as the systems where useful heat (or coolth) is degraded to provide comfort. This is followed by the analysis of HVAC systems as complex energy conversion devices where energy carriers are transformed into useful heat and coolth, and finally, the impact of HVAC energy consumption on energy resources is discussed. [Copyright &y& Elsevier]

Abstract: The shortcomings or limitations of the traditional approach to developing energy efficient buildings are that they can not determine: (1) the ideal thermophysical properties of building envelope material, where “ideal” means that such material can use ambient air temperature variation and/or solar radiation efficiently to keep the indoor air temperature in the thermal comfort range with no additional space heating or cooling; (2) the best natural ventilation strategy; (3) the minimal additional energy consumption for space heating in winter or air-conditioning in summer. To overcome these problems, some new concepts for developing energy efficient buildings are put forward in this paper. They are the ideal thermophysical properties of the building envelope material, the ideal natural ventilation rate, and a minimal additional space heating or cooling energy consumption. A new approach for determining these properties is also developed. In contrast to the traditional approach (the thermophysical properties of building envelope material are known and constant so that the relating equations describing the indoor air temperature tend to be linear differential equations), the new approach solves the inverse problem (thermophysical properties, etc. of a buildings are unknown), whose solution can be a function instead of a value. As a first step, the ideal specific heat of the building envelope material for internal thermal mass is analyzed for buildings located in various cities in different climatic regions of China, such as Beijing, Shanghai, Harbin, Urumchi, Lhasa, Kunming and Guangzhou. We found that the ideal specific heat is composed of a basic value and an excessive one which is of δ function for the cases studied. Some limitations that would need further study are introduced in the end of the paper. [Copyright &y& Elsevier]

Abstract: This paper describes the design and building technology details of a three-storey single family house located in the Pyrenees, in Andorra. The house is owned by the first author, and has been occupied since 2004. A combination of active and passive solar energy systems and night-time electricity are used to supply the heating and cooling demands. The main goal of this paper is to provide detailed design information and an evaluation of performance. Data provided includes site information and climate, basic design options and decisions, energy saving strategies and energy end use data. The house has been in use since 2003. This allows adequate performance data to be presented and evaluated. Some general results and initial design problems are discussed. [Copyright &y& Elsevier]

Highlights • Non-intrusive techniques are proposed to infer occupancy from existing HVAC sensors. • Reheat energy use is reduced by more than 38% with better nighttime setback schedules. • Derived a comprehensive set of candidate anomalous zones using unsupervised learning. • Proposed approach can be readily applied to any commercial building with a BMS. Abstract The Heating Ventilation and Air Conditioning (HVAC) system of commercial buildings traditionally runs on a fixed schedule that does not take occupancy into account despite its huge variation over space and time, thereby wasting a lot of energy in conditioning empty or partially-occupied spaces. Occupancy information is essential to eliminate wasteful energy use with imperceptible impact on building operations and human comfort. This paper investigates the application of non-intrusive techniques to obtain a rough estimate of occupancy from coarse-grained measurements of sensors that are commonly available through the building management system. Various static and adaptive energy-efficient schedules are developed based on this approximate knowledge of occupancy at the level of individual zones. Our experiments in three large commercial buildings confirm that the proposed techniques can uncover the recurring occupancy pattern of the zones, and schedules that incorporate these occupancy patterns can achieve more than 38% reduction in reheat energy consumption while maintaining indoor thermal comfort. [ABSTRACT FROM AUTHOR]

Abstract: This paper introduces and evaluates a novel heating and cooling concept employing thermo-active building systems and environmental energy, harnessed from two 11-m3 rainwater cisterns for a 285-m2 residential building in passive house standard in Germany. The building strives for a significantly reduced primary energy use with carefully coordinated measures, such as high quality building envelope, by means of vacuum insulated panels, supply and exhaust air system with heat recovery, reduced solar heat gains (solar shading), and the integration of thermal solar collectors and photovoltaic in the plant system. On this premise, a comprehensive long-term monitoring in high time-resolution was carried out for the building for two years with an accompanying commissioning of the building performance. Measurements comprise the energy use for heating, cooling, and ventilation, as well as the auxiliary equipment, the performance of the environmental heat source and sink (rainwater cistern), thermal comfort, and local climatic site conditions. The analysis focuses on the performance and the efficiency of rainwater cisterns as natural heat source and sink as well as the heat pump system. The paper discusses the performance of thermo-active building systems, investigates the thermal comfort, determines the efficiency of the heating/cooling system, and evaluates the total end and primary energy use of the building. [Copyright &y& Elsevier]

"Framework" and "case-study" are the two most prominent features in the optimization of architectural building design. The first can improve the speed of the process, the accuracy and integration of the outcome. The second can evolve the design knowledge of the various types of buildings in practice. This paper presents the "PCA-ANN integrated NSGA-III" framework that is a fast, accurate, and integrated solution for practical, erosive, and complicated building performance optimization problems, especially when the case study is a multi-type building such as a dormitory. The novelty and contribution of this paper exist in all three phases of its research framework. First, the dormitory building was parametrically modeled as a case study in two conventional dormitory building types. Second, an artificial model called PCA-ANN is presented in which problems that have a more complicated and practical case study with a multi-type building can be solved simply, integratively, and accurately. Third, the capabilities of NSGA-III are introduced and showed that it could be more accurate in comparison with NSGA-II, and then NSGA-III was integrated with the PCA-ANN model to solve the many-objective problem posed in this study. R2 score for PCA-ANN in the best-presented structure reached 0.99. In the overall best building alternative, energy efficiency and daylight performance for the whole year and thermal comfort performance in the free running period improved by 41.27%, 42.24%, and 15.57%, respectively, compared to its reference model. The presented framework can be applied and generalized to building energy optimization problems in practical and complex cases. • PCA-ANN and NSGA-III are integrated to optimize vast and complicated solutions. • Generative design of two dormitory types is set up to evaluate the main potentials. • The design space is discovered and datasets are generated for both types of building. • PCA-ANN is selected for the practical problem raised in this study from a comparison. • Final selection is made based on NSGA-III and the architect's conditional decisions. [ABSTRACT FROM AUTHOR]

Abstract: The paper deals with an optimization of parameters, which influence the energy and investment cost as well as the thermal comfort. The parameters considered in this study are: the insulation thickness of the building envelope, the supply-water temperature and the heat exchange area of the radiators. A combination of the building energy simulation software EnergyPlus 1 [1] Copyright by Lawrence Berkeley National Laboratories, Berkeley, CA, USA. and the generic optimization program GenOpt (see footnote 1) has been used for this purpose. The paper presents the application of a one-objective optimization algorithm solving the problems with two objectives, because the optimization algorithm is one-objective and the problem has two objectives, which are minimal total costs and satisfied thermal comfort. The total costs represent the sum of energy consumption and the investment costs. The thermal comfort is represented by Predicted Percentage of Dissatisfied (PPD) in this study. The optimization is used to determine the values of parameters that give the lowest sum of investment and energy cost, under the condition that the thermal comfort is satisfied. In addition, the optimization processes show the mutual influence of parameters on both the total cost and the thermal comfort. [Copyright &y& Elsevier]

The school playground is an essential part of any school building because of its important role in the overall teaching process. The study presents the current design of most of the governmental school playgrounds in Cairo and shows how existing playgrounds sustain this function and describes the inherent shortcomings of that design. Constructing a sports hall on the roof of the building is one of the solutions presented to overcome existing deficiencies. The paper presents the schematics of the concept along with the schematic diagrams for the interior of the hall. The study investigates the thermal criteria of the sport hall and how it serves the intended activity. Evaluation of the heat gain and thermal load of the structure-taking into account occupants, lighting and appliances, is carried out. The study also introduces the use of mechanical ventilation with the contributions of different heat-gain sources and considers the number of fans and fan velocity at the reference height and at the height of pupils, are calculated, to get the indoor air velocity for verifying the suitable heat-stress index and the thermal comfort. Model verification will be accomplished with a building under construction. The concepts presented in this paper would better serve the needs of schools, without harming the environment. [Copyright &y& Elsevier]

• 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]

Abstract Task/ambient air conditioning (TAC) system is reported to be an energy efficient technology with available methods to control thermal comfortable level for sleeping environments. However, the variation of indoor thermal environment will directly affect the performance of the TAC system, especially the set of operation parameters. Therefore, an optimization study on the TAC system operation considering the effects of envelope thermal load was carried out in this paper. Firstly, a full factorial design method was used to construct the models of the energy consumption and thermal comfort. Secondly, comfort lines were obtained to calculate the optimum operating parameters at which the energy consumption was at the lowest. Finally, the energy consumption at the optimum status was calculated. [ABSTRACT FROM AUTHOR]

This paper presents an autonomous hierarchical control method for a direct expansion air conditioning system. The control objective is to maintain both thermal comfort and indoor air quality at required levels while reducing energy consumption and cost. This control method consists of two layers. The upper layer is an open loop controller that allows obtaining tradeoff steady states by optimizing the energy cost of the direct expansion air conditioning system and the value of predicted mean vote under the time-of-use price structure of electricity. On the other hand, the lower layer designs a model predictive controller, which is in charge of tracking the tradeoff steady states calculated by the upper layer. Control performance of the proposed control method is compared to a conventional control strategy. The results show that the proposed control strategy reduces the energy consumption and energy cost of the direct expansion air conditioning system by 31.38% and 33.85%, respectively, while maintaining both the thermal comfort and indoor air quality within acceptable ranges, which validate the proposed methodology in terms of both comfort and energy efficiency. [ABSTRACT FROM AUTHOR]

Fuel poverty is a recognized and increasing problem in several European countries. A growing body of literature covers this topic, but dedicated analysis for Portugal are scarce despite the high perception of this condition. This paper contributes to fill this knowledge gap focusing on a European southern city while bringing new datasets and analysis to the assessment of this topic; consumer groups identification and to policy discussion. Daily electricity smart meters' registries were combined with socio-economic data, collected from door-to-door surveys, to understand the extent and the determinants of energy consumption for two contrasting consumer groups (herein called fuel poverty and fuel obesity groups). The analysis is based on the amount and annual profile of electricity consumption and was complemented with building energy simulations for relevant building typologies in those groups, to identify heating and cooling thermal performance gaps. The existence of these gaps allowed confirming and/or discarding the initial hypothesis of the poverty or obesity conditions. Results disclose socio-economic variables, as income, and consumers' behavior as key determinants of electricity consumption. It was identified a severe lack of thermal comfort levels inside households of both groups, either in cooling (98% for fuel poverty and 87% for fuel obesity) and heating seasons (98% for fuel poverty and 94% for fuel obesity). Major conclusion refers that electricity consumption cannot be used alone to segment consumer groups. This assessment may serve to support energy policy measures and instruments targeted to different consumers' groups. For example, distinct campaigns and differentiated incentives may apply to achieve energy efficiency and reduction while keep or improve indoor comfort levels. [ABSTRACT FROM AUTHOR]

Sustainable energy and thermal retrofit design of buildings or districts has a strong global impact in the viewpoint of economies and energy-efficiency perspectives. Several aspects such as architectonic design, building materials, construction technology, mechanical systems and outdoor climate determines the thermal behaviour of buildings and their ability to provide indoor thermal comfort to occupants. The use of geothermal energy and phase change materials (PCMs) in the construction systems are an opportunity that may attenuate indoor air temperature fluctuation as well as overheating risk. This paper presents the results of a study on indoor thermal comfort and energy efficiency regarding the PCM’s positive role when applied to new constructive solutions, inside a building with a geothermal system linked to the air conditioning system. The PCM study was based on real and simulated investigations in two rooms of a new university department at the Aveiro campus. Higrothermal monitoring (indoor air temperature) of two rooms in which one of them has PCM panels incorporated into gypsum board partition wall and into a suspended ceiling. The scope was driven to investigate the potential of these solutions for overheating mitigation. The numerical study was conducted by using an evolutionary algorithm coupled with the software EnergyPlus® used in simulations. In the scope of this optimization process, constructive solutions with the incorporation of different types of PCM with different melting temperatures and enthalpy, and different flow rates of natural ventilation were combined to investigate the potential and the payback time of these novel solutions. The results for the room measurements show that the indoor thermal comfort of the rooms, present long periods of discomfort namely in overheating. However, it was proved that the PCM application in one of the rooms lead to an overheating reduction of 7.23% representing a PCM efficiency of 35.49%. After the optimization process an overheating reduction of about 34% was attained by the use of PCM in one of the rooms. Regarding the economic analysis of the use of the PCM for cooling demand reduction, a payback time of 18 years was attained. [ABSTRACT FROM AUTHOR]

Thermally activated building system (TABS) is a hydronic cooling system, in which cold water is circulated through pipes embedded in the building structure to remove the heat from the indoor space. This paper proposes a hybrid passive cooling system, in which TABS is integrated with a cooling tower. The performance of this integrated system greatly depends on the climatic conditions of the geographical area. Hence, the feasibility of the proposed system to provide thermal comfort in twelve Indian cities spread over five different climatic regions is investigated using COMSOL Multiphysics. Different cooling scenarios like Roof and Floor cooled TABS (RF) and All Surfaces cooled TABS (AS) are compared. The proposed system performs well in arid and semi-arid regions, and the RF scenario is sufficient to achieve thermal comfort. The system is able to reduce the indoor operative temperature by 14 °C for the arid climatic conditions of Jaipur. In the other three regions, i.e., humid subtropical, tropical wet and dry and tropical wet regions, the performance of the proposed system is relatively low and the AS scenario is required to achieve thermal comfort. [ABSTRACT FROM AUTHOR]