This research is based on the challenge in the field of thermal comfort between the steady state and adaptive comfort theories. It challenges the concept of standard ‘comfort zone’ and investigates the application of ‘adaptive opportunity’ in the workplace. The research question is: ‘Does thermal control improve user satisfaction in cellular and open plan offices? Norwegian vs. British practices’. Currently, centrally controlled thermal systems are replacing individual thermal control in the workplace (Bordass et al., 1993, Roaf et al., 2004) and modern open plan offices are replacing traditional cellular plan offices in Scandinavia (Axéll and Warnander, 2005). However, users complaint about the lack of individual thermal control (Van der Voordt, 2003), which is predicted as an important asset to the workplace in the future (Leaman and Bordass, 2005). This research seeks users’ opinion on improving their satisfaction, comfort and health in two environments with high and low levels of thermal control, respectively the Norwegian and British workplace contexts. Two air conditioned Norwegian cellular plan offices which provide every user with control over a window, blinds, door and the ability to adjust the temperature are compared against two naturally and mechanically ventilated British open plan offices with limited thermal control over the windows and blinds for occupants seated around the perimeter of the building. Complimentary quantitative and qualitative methodologies are applied, with a particular emphasis on grounded theory, on which basis the research plan is formulated through a process of pilot studies. Occupants’ perception of their thermal environment within the building is recorded through a questionnaire and empirical building performance through thermal measurements. These traditional techniques are further reinforced with semi-structured interviews to investigate thermal control. A visual recording technique is introduced to analyse the collected information qualitatively regarding the context and meaning. The ASHRAE Standard 55-2010 and its basis do not apply to the case study buildings in this research. This thesis suggests that thermal comfort is dynamic rather than fixed. Occupants are more likely to prefer different thermal settings at different times, which is in contrast with providing a steady thermal condition according to the standard ‘comfort zone’. Furthermore, the occupants of the Norwegian cellular plan offices in this research report up to 30% higher satisfaction, comfort and health levels compared to the British open plan offices, suggesting the impact of the availability of individual thermal control. This research suggests that rather than providing a uniform thermal condition according to the standard ‘comfort zone’, office buildings are recommended to provide a degree of flexibility to allow users to find their own comfort by adjusting their thermal environment according to their immediate requirements.

The aim of the present research is to identify human subjective response (health and comfort) to the micro-thermal environment established by integration of individually controlled localized chilled beam and chilled ceiling (LCBCC) system and to compare its performance with the performance of mixing ventilation combined with chilled ceiling (CCMV).Experiments were carried out in mock-up of an office (4.1 m × 4.0 m × 3.1 m, L× W× H) with one person under two summer temperature conditions (26 °C and 28 °C). To mimic direct solar radiation in the room, five radiative panels on the wall together with electrical sheets on the half of the floor were used. The test room was set-up with two desks, as two workstations, and one laptop on each table. The main workstation (WS1) was located close to the simulated window. The second work station (WS2) was placed in the opposite side of the room. The room was equipped with two types of ventilating and cooling systems.  The first system consisted of a localized active chilled beam (LCB) unit together with chilled ceiling (CC) panels. The LCB was installed above the WS1 to create micro-environment around the occupant sitting at the desk. The supply flow rate from the LCB could be adjusted by the occupant within the range of 10 L/s to 13 L/s by means of a desk-mounted knob. The integration of mixing ventilation (MV) system and chilled ceiling panels was the second ventilating and cooling strategy. Twenty- four subjects (12 female and 12 male) were exposed to different indoor environment established by two cooling systems. Each experiment session lasted 120 min and consisted of 30 min acclimatization period and 90 min exposure period. The performance of the systems was identified and compared by physical measurements of the generated environment and the response of the human subjects. The study showed that perceived air quality (PAQ), overall thermal sensation (OTS) acceptability and local thermal sensation (LTS) acceptability clearly improved inside the micro-environment by using LCBCC system. Moreover, at the main workstation, OTS and LTS votes were close to “neutral” thermal sensation (ASHRAE seven point scale) when LCBCC system was used. However, OTS and LTS votes increased to the “slightly warm” side of the scale by applying CCMV system which implied the better cooling performance of the LCBCC system. Acceptability of work environment apparently increased under the room condition generated by LCBCC system. In agreement with human subjective study, the results from physical measurements and thermal manikin study showed that uniform thermal condition was generated all over the room. Air and operative temperature distribution was almost uniform with no difference higher than 1 °C between the measured locations in the room. Thus, both LCBCC and CCMV systems performed equally well outside of the micro-environment region. The use of the chilled ceiling had impact on the airflow interaction in the room and changed the airflow pattern. It can be concluded that the combination of convective and radiative systems can be considered as an efficient strategy to generate acceptable thermal condition in rooms.

Current building design and engineering practices emphasizing on energy conservation can be improved further by developing methods focusing on building occupants’ needs and interests in conservation. Specifically, the resulting energy effective building performance improvements cannot reach the desired goals, if the resulting indoor environmental conditions do not meet thermal, visual and air quality needs of the occupants. To meet both energy conservation and human performance requirements simultaneously requires to give the occupants information regarding indoor environmental qualities and energy implications of possible individual decisions. This requires that building control components and systems must enable occupants to understand how the building operates and how their own actions meet both their needs and the energy and environmental goals of the building project. The goal of the research and experiments of this dissertation is to explore if real-time information regarding visual comfort requirements to meet a variety of tasks and to simultaneously conserve energy, improves occupant behavior to meet both objectives. Two workplaces in Robert L. Preger Intelligent Workplace were equipped to test the performance of 60 invited participants in conducting computer based tasks and a paper based task, under three difference lighting controls: 1) Centralized lighting control with no user choice 2) User control of - blind positions for daylight shading - ceiling based lighting fixture luminance output level - task lighting: on/off 3) User control the three components (as listed under point 2 above), with provided simultaneous information regarding energy and related CO2 emissions implications, appropriate light levels meeting tasks requirements, and best choices in order to meet both task requirements and energy conservation goals/objectives. The main findings of the experiments are that real-time information (listed under point 3 above) enables users to meet the visual quality requirements for both computer tasks and the paper task, and to conserve significant amounts of electricity for lighting. Furthermore, the 60 invited participants were asked to identify the importance of the four types of provided information tested in point 3 above. While individual users identified the importance of different information categories, the overall assessment were considered to be significant.