Conference Agenda

This research focusses on the role and importance of human presence and interactions on the quality and effectiveness of care delivery processes that take place in indoor environments during a (future) pandemic. With these insights the effectiveness of ventilation and social-distancing as a mitigating measure in an airborne respiratory pandemic is researched. In six different healthcare facilities, eight rooms were investigated. The buildings have different construction years, floor area of 5-23 m2 per resident, different ventilation systems and include day activity areas (3) and living rooms (5) within elderly care (4) and disabled care (4).

Used methods involve a (i) technical inventory, (ii) position and distance determination measurements and (iii) observations. The technical inventory is used to gain insight in the building and building ventilation systems. Position determination is done with wearable sensors that monitor positions of persons (residents, staff, visitors) over time and post-processing of data. Observations are done to register contacts between persons as well as the nature and intensity of the contact.

In 75% of the investigated rooms, a mechanical ventilation system is present. However, in most cases, the designed volume flow is not obtained. Analyzing contact time at < 1.5 m and > 1.5 m can provide insights into the impact of ventilation on exposure. Contact time at > 1.5 m is longer for both staff and residents, with large variation between different locations in the room. Most registration occurred around central seating areas (dining tables and sofas). Longer contact times were recorded during meals in living rooms, while day care areas showed longer contact times outside meal times. Residents were involved in approximately 90% of the contact moments and they stay in a room for a longer period of time. Staff, on the other hand, regularly walks between the seats and the kitchen or pantry.

Ensuring a satisfactory indoor environmental quality (IEQ) stands as the primary objective of HVAC systems. To deliver occupants' preferred IEQ conditions at the lowest energy cost, a suitable HVAC control needs to be defined, including setpoints. Conventional control systems often rely on fixed temperature setpoints based on thermal comfort models predicting preferences of a group (e.g. Fanger's PMV-PPD model). However, this control is non-responsive to the occupants and their comfort preferences. Occupant-centric control (OCC) is an alternative and integrates occupant presence, preferences and behaviour. A promising technique for OCC is the mixed-effects (ME) modelling approach, which can predict occupants’ preferences. This regression-based approach can account for the individuality of each occupant.

This paper aims to develop and demonstrate an occupant-centric control (OCC) framework integrating these ME models predicting the occupants’ thermal and IAQ satisfaction in a lecture room of an educational building.

This OCC framework comprises of the following three steps: (1) Data collection and pre-processing, (2) ME model definition and computation of comfort ranges and (3) Temperature setpoint determination. The data consist of occupants’ thermal and IAQ satisfaction feedback and measurements of IEQ conditions in the lecture room.

The second part of the paper demonstrates the developed OCC framework in the test lecture rooms at Campus Ghent of KU Leuven with an all-air system for heating, ventilation and cooling (Belgium). The impact of the OCC is assessed in terms of occupant satisfaction and HVAC system energy use (heating and fan energy) via a building energy simulation study in Modelica in the Dymola environment. The performance of the OCC is compared to a baseline scenario with a fixed temperature setpoint based on Fanger’s comfort theory.

Several decades of research has established that classroom thermal environment and indoor air quality (together, the indoor climate) impact student comfort, health, and learning. There remains a dearth of research on classroom indoor climate and the relevant standards still follow the benchmarks set for adults, even with accumulating evidence that children perceive the thermal environment differently from adults.

To design a fit-for-purpose methodology for studying classroom indoor climate, in a pilot study, we adopted a design thinking (DT) approach. In addition to product design, DT can be applied to design services, processes, and strategies. A DT approach allowed us to engage the end-users and understand their viewpoint. It also helps, through clarification and ideation, improve students’ awareness of real-world implications of poor air quality and the impact of human behavior on air quality.

In such a pilot exercise undertaken in the capital region of Denmark, we engaged students from five classes in a DT initiative to better understand how indoor climate studies for school classrooms should be designed. We covered three of the five stages of DT in the process: Empathize, Clarify, and Ideate. Multiple interaction sessions were organized with the students. We discussed the parameters of indoor climate, the student’s experience of these parameters in the classroom, and how to monitor them. The classroom indoor climate was monitored for two to three weeks. Together with the students, we reviewed the data to ideate on the factors that could explain variation in readings, to brainstorm possible mitigatory steps that could be taken, and to document how they would like to implement indoor climate monitoring. Outcomes of the work include ideation and engagement tools developed and the feedback collected regarding indoor climate monitoring and collecting responses from children.

Recent studies have extensively highlighted the critical role of occupant behaviour in demand management strategies such as Demand Response (DR), and Direct Load Control (DLC) as user response directly impacts the effectiveness of these strategies. This highlights the necessity of integrating occupant behaviour into the design and implementation of DR to enhance the success of these programs. In line with this, this paper investigates how occupant thermal preferences and building envelope characteristics jointly influence the effectiveness of DLC strategies for residential buildings in cold climates. Using EnergyPlus and its Python API, we simulate two distinct occupant behaviour profiles namely, Prefer Warmer and Prefer Cooler, in buildings with either Poor or Good Envelope performance. The analysis includes a fixed DLC scenario with and without user override, followed by a comprehensive parametric evaluation of various preheating and setback combinations. Results show that DLC performance varies significantly depending on the occupant-building pairing. Without override, substantial peak demand reductions are possible; however, user overrides can diminish these benefits to varying degrees, depending on the occupant type and building characteristics. The parametric analysis reveals that Prefer Cooler users often benefit from deep setbacks without the need for preheating, while preheating becomes more beneficial under mild setbacks for this user profile to help shift the heating load. In contrast, Prefer Warmer users require preheating, particularly under aggressive setbacks, to reduce discomfort-driven overrides. Building envelope quality further affects these outcomes. These findings highlight the limitations of one-size-fits-all DR strategies and underscore the need for tailored DLC configurations that consider both occupant behaviour and building thermal performance. The study provides practical insights for designing occupant-centric DLC programs that enhance grid flexibility without compromising comfort.

Personalized comfort systems (PECS) are an emerging solution able to combine increased environmental comfort conditions for users and to reduce the buildings energy performance. The present study focuses on the potential of desk lighting and heating systems in comparison with conventional systems. The work is carried out in the ENEA Living Lab, a working space of 11 rooms, located in an office building in the northern outskirts of Rome. Seven rooms are west oriented, 5 of them host 5 workers and 2 have single occupancy; of the four east oriented rooms, one hosts 1 worker, the remaining host 2. Each room has an air conditioning unit (2.5kW nominal power) that can be operated automatically by the building energy management system BEMS) or by the users. The artificial lightings system consist of three luminaries each equipped with 2 lamps (either near or LED type). The Living Lab hosts 19 users in total, for the experiment 7 will use the conventional systems and 12 will have installed PECS. They consist of 360W desk fan heater and 10W desk lamp. The users in the conventional rooms fix the set-points according to their comfort requirements; in case if PECS, the heating room set-point is fixed at 18°C and the room lighting system is switched off. The users are asked to manage their visual and thermal comfort using the desk devices, and to change the initial setting only if comfort conditions are not achieved. All the central and desk systems are connected to the BEMS to measure the electricity uses in all rooms and for all occupants. In parallel, the latter will evaluate their comfort by answering and on-line survey, ad-hoc developed, twice per day. This study will allow to understand performance and acceptance of PEC technologies by real field studies.