•Environmental control should address thermal comfort and energy efficiency simultaneously•Optimization algorithm with user sensitivity and PCS effect can save energy•Thermal preference is ...recommended for personal models and PCS performance evaluation•New technologies minimize user interaction demand to monitor personal variables•New types of PCS maximize mobility through wearable solutions
Personal conditioning systems (PCS) enable increased thermal comfort and acceptability conditions in a wider temperature range, resulting in energy savings. Many studies analysed the thermal effect and energy efficiency of these systems, although the association between these two goals in practice is not that simple. In order to identify possible answers to understand what remains to be discussed on this subject, a review of recent publications on PCS was carried out, mainly focused on its implementation in shared office spaces. The reviewed publications shed some light on the use of personal comfort models associated with environmental control for system automation, as well as the development of new technologies that facilitate data acquisition and the proposition of new personal conditioning systems. The application and proposition of wearable systems and the development of textiles for smart clothing is an identified trend seeking greater mobility and flexibility of PCS use, although its integration to environmental management systems is challenging. Thus, this review discloses some questions that should be considered for the implementation of PCS and personal comfort models in real environments, including some insights based on current publications on the subject.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Desk fans allow individual thermal adjustment in shared spaces which increases occupants' thermal satisfaction. When associated with the increase of room conditioning system setpoint temperature, ...they can also reduce energy use. In comparison to other Personal Comfort Systems (PCS), low-power desk fans can be very efficient for cooling. Nevertheless, previous studies identify some barriers to their implementation and show no clear guidelines on how to overcome them. Therefore, this study presents the results of a field implementation of desk fans in an open office in Brazil. The intervention consisted of providing one desk fan for each occupant and progressively increasing the setpoint temperature. Indoor thermal conditions were recorded simultaneously with occupants' thermal perception using sensors and surveys. Results show fans increased thermal satisfaction by 20 %. And, when fans were available, the preferred indoor air temperature increased by 1 °C. However, many constraints affect the results. Based on this experience, we propose guidelines for future implementation. We emphasize the need to understand the HVAC system, engage building operators, and apply gradual temperature modification. As occupants’ expectations had a great impact on the potential temperature extension, we suggest a way to limit temperature extension in future implementations.
Display omitted
•Fans increased thermal satisfaction by 20 %.•80 % occupants considered 1 °C higher air temperature comfortable with fans.•Setpoint temperature increment must be gradual.•90th pre-intervention temperature percentile suggested to limit setpoint increment.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•This article proposes an operation strategy for NZEB under suboptimal conditions.•Mixed-mode operation with PCS enables 20% to 40% of energy savings.•Optimal set point temperatures are defined based ...on ASHRAE 55 adaptive thermal comfort.•The strategy enables 6-floor buildings to become NZEB in warm climates.•Reductions from 33% to 65% of extra PV area to become PEB is achieved.
Positive energy buildings (PEB) are foreseen to help achieving global emissions reduction targets and decarbonisation. However, for vertical office spaces in urban centres the photovoltaic (PV) production area is restricted, so innovative strategies are needed. For cooling-dominated climates the extension of set point temperature associated to local control of air movement has the potential to increase the use of natural ventilation and generate a great amount energy savings. . Therefore, this study aims to identify to what extent adopting a mixed-mode operation with desk fans could help mid-rise office buildings to become NZEBs in warm climates. To verify the impact of this strategy, computer simulations were carried out with three building heights in four Brazilian cities. Results show this strategy can generate 20–40% energy savings and the set point could be extended up to 28 °C or 30 °C depending on the climate, without jeopardizing occupants’ thermal comfort. Thus, in warm climate cities, the strategy allows lower buildings to become PEBs and mid-rise buildings to become NZEBs. In addition, the demand for extra PV area is expressively reduced, increasing the viability of mid-rise PEBs. This study adds innovative knowledge for achieving PEB targets under suboptimal conditions and highlights multiple aspects that should be considered for applying this strategy.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A repository on occupant-centric control and operation case studies is proposed.•A survey was developed to collect and present the data systematically.•The current database includes 58 OCC case ...studies with different approaches.•Results show a lack of studies on lighting and building operators.•Occupant modeling is more commonly implemented for responsive controls.
Occupant-centric controls (OCC) and operations have emerged as a key concept in shifting the focus from conventional building- (or system-) centric operations to a more occupant-centric approach. Despite the potential of OCC to meet occupants’ demands and bridge buildings’ energy performance gap, its implementation in real-world settings has been limited. In addition, there is a lack of standardization in methodologies and terms to facilitate meaningful comparisons among case studies. Therefore, this paper aims to present a repository of OCC case studies, offering a platform for standardization and presenting key information about practical implementations of these strategies in real-world scenarios. To accomplish this, descriptors, terms, and concepts about OCC case studies were discerned through a literature review. These elements were systematically integrated into a structured survey to capture comprehensive information on OCC field study implementations. This paper provides an overview of the survey structure and insights into the current dataset, which comprises a total of 58 OCC case studies. By publishing the case study repository, we intend to establish standard categories for OCC strategies and to offer researchers and practitioners a database through which they can understand trends and possibilities for implementing OCC strategies.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Occupant-Centric Control and Operation (OCC) represents a transformative approach to building management, integrating sensing of indoor environmental quality, occupant presence, and occupant-building ...interactions. These data are then utilized to optimize both operational efficiency and occupant comfort. This paper summarizes the findings from the IEA-EBC Annex 79 research program's subtask on real world implementations of OCC during the past 5 years. First, in Q1 and Q2, we provide a definition and categorization of OCC. Q3 addresses the role of building operators for OCC, while Q4 describes the implications for designers. Then, Q5 and Q6 discuss the role and possibilities of OCC for load flexibility, and for pandemic induced paradigm shifts in the built environment, respectively. In Q7, we provide a taxonomy and selection process of OCC, while Q8 details real world implementation case studies. Finally, Q9 explains the limits of OCC, and Q10 provides a vision for future research opportunities. Our findings offer valuable insights for researchers, practitioners, and policy makers, contributing to the ongoing discourse on the future of building operations management.
•Expert summary on recent developments in occupant-centric control (OCC).•We introduce definitions and categorizations of OCC.•We address the role of building operators and the implications for designers.•We discuss the role of OCC for load flexibility.•We explain the limits of OCC and provide future research directions.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Display omitted
•72 interviews were performed with operators in 7 countries and 5 climate zones.•Climate influences complaint but does not explain setpoint temperatures differences among ...countries.•Most operation aspects and drivers are influenced by country-related aspects.•There is a great untapped potential for control systems (BMS/BAS) worldwide.•Guidelines and standards are needed worldwide for adaptive, and occupant centered operation.
Occupant-centric building design and operation has attracted recent research efforts in many countries, as building occupants are being more recognized as the main drivers in planning and operating safe, comfortable, energy-efficient indoor environments. In this matter, the role of building managers and operators is crucial to capture the needs of occupants and to adapt the response of the building accordingly. IEA EBC Annex 79 participants conducted 72 interviews with operators and facility managers across 7 countries (Brazil, Canada, Germany, Italy, Poland, Singapore, and USA) covering a wide range of ASHRAE 169 climate zones (from 0 to 5 in the climate classification). This paper presents a qualitative cross-case analysis of operators’ perspectives and experiences to identify regional differences. Therefore, the analyses are based on the hypotheses that climate or other country-related aspects would be the main drivers of building operation procedures differences. Results show climatic differences have little influence on building management, while occupants' complaints are very influenced by them. Moreover, operators are lacking clear tools, like guidelines and standards, on how to optimize building management in a climatic-adaptive and occupant-centric manner. Therefore, the development of operation protocols for building sustainable operation respecting climatic context and occupants’ control is recommended.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The use of personal fans allows improving thermal comfort and energy savings in warm office spaces. This is due to individual adjustment and extended indoor temperature acceptability. However, to ...achieve that, the usability of fans must be assured. Therefore, an experiment with 40 people of various age groups was carried out to assess four types of fans, one of which is an evaporative cooling device. The goal was to find out which criteria should be used for selecting a fan to implement in an office space. Results show that airflow sensation and speed adjustment are considered the most important, although, noise is also very important, and cost can be an eliminatory criterion. The evaporative device was the best rated even in a space with 70 to 80% relative humidity, as users considered it to have a smooth controllable airflow. The results highlight these aspects should be considered in the selection of a personal fan and could also drive the industry to improve fans design for increasing usability and expanding the use of these systems.
•A questionnaire study was conducted in 26 countries, using 21 different languages.•This international collaboration led to a dataset of 8225 questionnaires.•Only a subset of the responses are in ...accordance with the assumption of equidistance.•Relationship between sensation and comfort perception varies with context.•Cluster analysis revealed significant differences between groups of participants.•Interpretation of scales varies with climate, season and language.
People's subjective response to any thermal environment is commonly investigated by using rating scales describing the degree of thermal sensation, comfort, and acceptability. Subsequent analyses of results collected in this way rely on the assumption that specific distances between verbal anchors placed on the scale exist and that relationships between verbal anchors from different dimensions that are assessed (e.g. thermal sensation and comfort) do not change. Another inherent assumption is that such scales are independent of the context in which they are used (climate zone, season, etc.). Despite their use worldwide, there is indication that contextual differences influence the way the scales are perceived and therefore question the reliability of the scales’ interpretation. To address this issue, a large international collaborative questionnaire study was conducted in 26 countries, using 21 different languages, which led to a dataset of 8225 questionnaires. Results, analysed by means of robust statistical techniques, revealed that only a subset of the responses are in accordance with the mentioned assumptions. Significant differences appeared between groups of participants in their perception of the scales, both in relation to distances of the anchors and relationships between scales. It was also found that respondents’ interpretations of scales changed with contextual factors, such as climate, season, and language. These findings highlight the need to carefully consider context-dependent factors in interpreting and reporting results from thermal comfort studies or post-occupancy evaluations, as well as to revisit the use of rating scales and the analysis methods used in thermal comfort studies to improve their reliability.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Thermal discomfort is one of the main triggers for occupants' interactions with components of the built environment such as adjustments of thermostats and/or opening windows and strongly related to ...the energy use in buildings. Understanding causes for thermal (dis-)comfort is crucial for design and operation of any type of building. The assessment of human thermal perception through rating scales, for example in post-occupancy studies, has been applied for several decades; however, long-existing assumptions related to these rating scales had been questioned by several researchers. The aim of this study was to gain deeper knowledge on contextual influences on the interpretation of thermal perception scales and their verbal anchors by survey participants. A questionnaire was designed and consequently applied in 21 language versions. These surveys were conducted in 57 cities in 30 countries resulting in a dataset containing responses from 8225 participants. The database offers potential for further analysis in the areas of building design and operation, psycho-physical relationships between human perception and the built environment, and linguistic analyses.
PDF
