• Energy Research

Abstract Literature shows that both building systems and occupants’ behaviour contribute to the amount of energy used to create a comfortable indoor environment. To determine possible relationships, energy consumption of nine school buildings was studied in relation to identified building characteristics, self-reported frequency of teachers’ actions, and (perceived and measured) indoor environmental quality (IEQ) of the school children in the classrooms studied. These schools were located in different areas in the Netherlands, and their yearly energy consumption differed a lot. Results demonstrated significant relationships of electrical energy consumption with lighting distribution in classrooms and the frequency of teachers’ light switch behaviour: the higher the measured illuminance in the classrooms, the more electricity was used in the school building. The more electricity was used, the more children complained about the IEQ in their classrooms; and the more frequently the teachers turned on the light, the less electricity the schools consumed. It was concluded that stimulating teachers to be more active in controlling the light might lead to energy saving, but a larger sample of schools with more variation in buildings systems is required to confirm this.

Abstract Pollution sources were quantified by the new olf unit in 20 randomly selected offices and assembly halls in Copenhagen. The spaces were visited three times by 54 judges, who assessed the acceptability of the air: (1) while unoccupied and unventilated to quantify pollution sources in the space; (2) while unoccupied and ventilated to quantify pollution sources in the ventilation system; and (3) while occupied and ventilated to determine pollution caused by occupants and smoking. Ventilation rates, carbon dioxide, carbon monoxide, particulates, and total volatile organic compounds were measured, but did not explain the large variations in perceived air quality. For each occupant in the 15 offices there were on average 6–7 olfs from other pollution sources; 1–2 olfs were situated in the materials in the space, 3 olfs in the ventilation system, and 2 olfs were caused by tobacco smoking. The ventilation rate was 25 l/s per occupant, but due to the extensive other pollution sources only 4 l/s per olf. This explains why an average of more than 30% of the subjects found the air quality in the offices unacceptable. The obvious way to improve indoor air quality is to remove pollution sources in the spaces and in the ventilation systems. This will at the same time improve air quality, decrease required ventilation and energy consumption, and diminish the risk of draughts.

Indoor environmental quality (IEQ) is an important quality aspect of office buildings, which is acknowledged in a new European methodology and software for office building refurbishment (TOBUS). In TOBUS, an inventory of complaints from occupants about IEQ is made as well as an inventory of characteristics of building and HVAC-system. Based on relations between characteristics of buildings and systems and the use of the building, different possible causes for the problems can be identified and possible actions for improvement can be selected. A relation scheme is provided with relations between objects and types, complaints of occupants in an office building, possible causes of those complaints and actions that should take away those complaints. Furthermore, a relation scheme is provided with causes and actions that cannot be related to an object. A procedure to qualify and quantify the IEQ performance of a building is given. This article describes the results of the field investigations in 12 European buildings focused on the IEQ part. Discussions and conclusions from this field study with respect to IEQ and with respect to the methods and procedures used are also presented.

A previous study clustered home occupants into archetypes with a questionnaire. This study uses qualitative methods to strengthen those previously-found archetypes with data pertaining to the participants’ home experiences. Focus groups were carried out where generative activities were conducted involving the generation of collages. The first activity dealt with the expression of ‘meaning of energy use at home’ and the second one with the ‘ideal home experience’. Analyses were done with content and thematic analysis. Codes were drawn from the data and were assimilated through an affinity diagram. The diagram produced two categories: building themes and human themes, along with five sub-categories (home, financial, energy, psychological, and behavioural aspects). The outcome shows that each archetype expresses needs and meanings of an ideal home experience and energy use differently from each other. The results provide evidence that generative techniques can be used in energy research. In this case, to validate and substantiate the quantitative archetypes previously produced with a questionnaire. Interpretive knowledge in energy research allows for a better understanding of occupants’ differing behavioural patterns in regards to energy use and comfort. It allows customizing interventions to the archetypes’ specific needs to decrease energy consumption while maintaining comfort.

The thermal environment in educational buildings is crucial to improve students’ health and productivity, as they spend a considerable amount of time in classrooms. Due to the complexity of educational buildings, research performed has been heterogeneous and standards for thermal comfort are based on office studies with adults. Moreover, they rely on single dose-response models that do not account for interactions with other environmental factors, or students’ individual preferences and needs. A literature study was performed on thermal comfort in educational buildings comprising of 143 field studies, to identify all possible confounding parameters involved in thermal perception. Educational stage, climate zone, model adopted to investigate comfort, and operation mode were then selected as confounding parameters and discussed to delineate the priorities for future research. Results showed that children often present with different thermal sensations than adults, which should be considered in the design of energy-efficient and comfortable educational environments. Furthermore, the use of different models to analyse comfort can influence field studies’ outcomes and should be carefully investigated. It is concluded that future studies should focus on a more rational evaluation of thermal comfort, also considering the effect that local discomfort can have on the perception of an environment. Moreover, it is important to carefully assess possible relationships between HVAC systems, building envelope, and thermal comfort, including their effect on energy consumption. Since several studies showed that the perception of the environment does not concern thermal comfort only, but it involves the aspects of indoor air, acoustic, and visual quality, their effect on the health and performance of the students should be assessed. This paper provides a way forward for researchers, which should aim to have an integrated approach through considering the positive effects of indoor exposure while considering possible individual differences.

In the frame work of the European project EPIQR (energy performance, indoor air quality, retrofit), European apartment buildings were investigated with a newly developed tool called EPIQR. This tool is aimed at assessing information on refurbishment and retrofitting needs of apartment buildings. This package is, however, not only meant to identify the possible refurbishment/retrofitting needs but also to identify the possible improvements that can be made to result in a better indoor environment and a lower energy consumption. As part of the EPIQR tool (a user-friendly software programme), procedures and methods were developed to be able to investigate indoor environment quality (IEQ) in apartment buildings. Among others a questionnaire was developed. In this paper the methods and instruments related to IEQ developed for EPIQR are described and the results of the field study in the apartment buildings are reported and analysed [P.M. Bluyssen, EPIQR: IEQ part of EPIQR from 1 June 1996 to 1 June 1998, TNO Report 98-BBI-R0844, May, 1998].

Abstract Occupants’ comfort perception affects building energy consumptions. To improve the understanding of human comfort, which is crucial to reduce energy demand, laboratory experiments with humans in controlled environments (test rooms) are fundamental, but their potential also depends on the characteristic of each research facility. Nowadays, there is no common understanding for definitions, concepts, and procedures related to human comfort studies performed in test rooms. Identifying common features would allow standardising test procedures, reproducing the same experiments in different contexts, and sharing knowledge and test possibilities. This review identifies 187 existing test rooms worldwide: 396 papers were systematically selected, thoroughly reviewed, and analysed in terms of performed experiments and related test room details. The review highlights a rising interest in the topic during the last years, since 46% of related papers has been published between 2016 and 2020. A growing interest in non-thermal sensory domains (such as visual and air quality) and multi-domain studies about occupant's whole comfort emerged from the results. These research trends have entailed a change in the way test rooms are designed, equipped and controlled, progressively becoming more realistic inhabitable environments. Nevertheless, some lacks in comfort investigation are highlighted: some continents (like Africa and South America) and climate zones are found to be underrepresented, while involved subjects are mainly students performing office tasks. This review aspires to guide scientists and professionals toward the improved design or the audit of test room experimental facilities, especially in countries and climate zones where human comfort indoors is under-studied.

There is a need for reducing dwellings’ energy consumption while maintaining a comfortable and healthy indoor environment. This review was performed to provide a steppingstone for identifying new methods for studying everyday home energy use and comfort. First, an overview of comfort is given as seen from different disciplines, depicting the subjective and multidimensional nature of comfort. This is followed by the biological component of comfort, reflected as an emotional, behavioural, and physiological reaction to environmental stimuli. Subsequently, links between comfort, health, and wellbeing are introduced. The second part of the review focuses on energy and buildings, with the connection between energy and behaviours-detailing possible explanations of performance gaps, and the pathways from energy to health. To conclude, human sensation of comfort is more complex than the perception of thermal, acoustical, visual stimuli, or air quality environment. Comfort is a reaction to the environment that is strongly influenced by cognitive and behavioural processes. Habits and controllability have been identified as paramount in the links between comfort and energy consumption. In this holistic view of comfort linked to health, comfort is referred to as ‘wellbeing’. The first steps for new directions of the study of comfort and energy are presented.