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

In buildings, occupant behaviour is recognised as a major contributing factor to energy demand and in particular to heating consumption. To achieve thermal comfort within the heating season, people report to use heat in very different ways; for example behaviours include switching on the heating system, putting on warm clothes, drawing curtains, changing rooms, making a hot drink and using a hot water bottle. While research has focused on subjective accounts using interviews, diaries and questionnaires, little is known about the frequency and probability of these behaviours. Using a mixed-method approach, this paper reports on the results of a field study in dwellings using wearable and environmental sensors. The analysis investigates the probability of these behavioural responses as a function of seven independent variables; (1) external and (2) internal monitored temperature, (3) probability of heating being on or off, (4) time of the week, (5) time of the day, (6) the three categories of the predictive thermal comfort model, and (7) the three categories of the adaptive thermal comfort model. Results show that participants were more likely to increase their clothing and activity level as internal temperature decreased, although there was no significant change in activity level throughout the course of a day. Methodologically, this paper demonstrates the effectiveness of different statistical tools in analysing occupants’ behaviours. Substantively, this paper emphasises the need for future research to gather objective data on what people do. [ABSTRACT FROM AUTHOR]

The aim of this paper is to study and compare the temperature profile and energy performance of traditional and Vegetative Roofs (VRs) during winter season in Lebanon, a country in the Middle East. Three roof mockups were installed on the rooftop of the Chemical Engineering Department at the University of Balamand: a Traditional Gravel Ballasted Roof (TGBR) and two Extensive Green Roofs (EGRs) with different substrate depth and composition. Each minute, the temperature of air, on TGBR surface, and at different depths of EGR was recorded. The daily cooling and heating demands were also calculated. Results confirmed that VRs protect the roof membrane from high temperature fluctuations and decrease air temperature by a factor of one and a half during sunny winter days ( T airmax = 32 ° C ). Findings of this study also showed that the total cooling demand of EGR decreased by 90% compared to TGBR. [ABSTRACT FROM AUTHOR]

• Listed dwellings of southern Spain were monitored in winter to evaluate IEQ and EP. • Lengthy high rates of IRH were observed. • High levels of CO 2 concentration were recorded in bedrooms at night. • Thermal comfort is only achieved through a constant use of the heating systems. • Heat losses are entirely building-driven. Although European heritage buildings are excluded from energy efficiency targets, it would be beneficial to include the largest group, that of listed housing, in energy retrofit plans, in order to encourage its occupation and contributing to the sustainable maintenance of historic cities. This requires reliable experimental studies, which have been rare so far, in order to establish energy rehabilitation plans that do not jeopardize the conservation of their values. This paper aims to contribute to addressing this gap. It evaluates the energy performance and indoor environmental quality of dwellings within listed buildings of the conservation area of Seville, Spain, in the Mediterranean climate zone, under actual winter use and occupation conditions. An experimental campaign was conducted, generating energy models and measuring rates of indoor air temperature to validate them. The findings highlight important health and environmental issues: despite the mild winters of southern Spain, intensive use of the heating system is needed to maintain thermal comfort indoors, increasing polluting emissions; CO 2 concentration in bedrooms is usually excessive overnight and, regularly, indoor relative humidity remains too high; heat losses depend entirely on the physical condition of the constructive elements (walls, roofs, air leakage and glazing) which occupants cannot easily improve. [ABSTRACT FROM AUTHOR]

• An optimized operation strategy is proposed for ASHP heating of school buildings. • Effects of different combinations of start-up times and return water temperatures on power consumption are compared. • A longer warm-up time with a lower water temperature can save more energy. Air-source heat pump (ASHP) has been widely applied in heating systems of school buildings. In order to achieve building energy efficiency while ensuring indoor thermal comfort, the paper compared the effects of different operation strategies including intermittent heating mode in non-working hours and setpoint of return water temperature in working hours. A middle school building in Tianjin, China is chosen as a case study and its physical model is developed by using the EnergyPlus tool. After verifying the validity of the model, the article simulated 64 different operation conditions produced by combining 8 start-up times with 8 return water temperature setpoints to find a better operation mode of the intermittent heating. Results indicate that running at a lower water temperature with an earlier start-up time is more energy efficient compared with running at a higher water temperature with a later start-up time while meeting the thermal comfort requirement. In addition, by changing the return water temperature setpoints hourly based on the outdoor air temperatures, the situation of overheating and undercooling during working hours has been well improved and the energy saving rate is about 17% during the entire heating season. [ABSTRACT FROM AUTHOR]

This paper presents a field study carried out on a novel self-regulating active beam system installed in an office building located in Jönköping, Sweden. The system consists of two parts: an air handling unit (AHU) to satisfy ventilation requirements, and a water circuit to meet sensible heating and cooling loads. The novelty of the system is in relation to the water circuit, which is able to provide simultaneous heating and cooling through a single loop with water at near room air temperature. The field study evaluated both the performance of the system and the indoor climate in the building. The performance of the system was monitored for a one-year period through sensors placed along the water circuit and the AHU. The indoor climate in the building was assessed by measuring relevant physical parameters and by conducting a survey among occupants. Results show that the system is capable of maintaining indoor air temperatures between 21 and 24 °C by circulating water at temperatures of about 22 °C. The annual average indoor air temperature during working hours was 22.6 °C ± 0.6 °C, indicating low variation during the year. Answers to questionnaires revealed that occupants were satisfied in terms of thermal comfort, achieving an acceptability rate of 90%. An average thermal sensation vote of −0.38 in winter and −0.48 in summer was obtained, indicating that occupants generally felt slightly cold. [ABSTRACT FROM AUTHOR]