Individual thermal control in the workplace : cellular vs open plan offices : Norwegian and British case studies

Abstract

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.