Browsing Department of Mechanical Engineering & the Built Environment by Subjects
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Environmental control and sick building syndrome; a comparison between a low carbon open plan and a cellular plan workplaceThis study investigates the effect of environmental control on Sick Building Syndrome (SBS). This is examined by environmental measurement, user health and satisfaction at two workplaces with respectively low and high levels of individual control over the thermal environment. The Anglo-Saxon practice of the open plan workplace is compared to the traditional Scandinavian practice, with a greater preponderance of cellular office accommodation. The research will lead to the formulation of specific strategies to enhance opportunities in providing thermal comfort in the workplace. Two case studies are described with respectively low and high provision of individual environmental control. A low energy open plan office in Scotland is selected with natural ventilation, where limited users have access to windows. In contrast, an air conditioned cellular plan office in Norway with excessive use of energy is selected providing every user with control over a window and the ability to adjust heating and cooling. Complementary quantitative and qualitative methodologies are applied. Particular emphasis is given to Grounded Theory methods. Building users’ health conditions and perception of their thermal environment are recorded through a questionnaire and empirical building performance through the measurement of the thermal environment. These traditional techniques are further reinforced with semi-structured interviews to investigate the environmental control. A new visual recording method is applied to qualitatively analyse the subject in its context. Information regarding all users and their environment is applied as colour codes to floor plate layouts. The study examines the significance of environmental control and its effect on Sick Building Syndrome in a comparison between a low carbon open plan and a cellular plan workplace with higher energy consumption. Through this a balanced appraisal can be made of comfort profiles and user’s health between the two benchmarked buildings.
Health, Energy and Thermal Comfort.This study examined the impact of providing thermal control systems on occupants’ wellbeing in two particular European contexts, including a Norwegian cellular plan office with high levels of thermal control and a British open plan office with limited thermal control. The former provided each occupant with a personal office, within which openable windows, blinds, door and the ability to control the temperature was provided. In the Norwegian approach, personal differences in perceiving the thermal environment were respected and the architectural design of the building allowed each individual to set the thermal environment. In contrast, limited openable windows were provided for occupants seated around the perimeter of the building in the open plan office. The main strategy in the British approach was to provide a uniform thermal environment for all occupants according to the standard comfort zone. Natural ventilation was the main system, while in the Norwegian practice a combination of natural ventilation and air conditioning was in operation. As a result, the energy use of the Norwegian practice was much higher than the British practice. A field study of thermal comfort was applied. Survey questionnaires, environmental measurements and interviews were conducted. The Norwegian occupants reported much higher health rate up to 40% compared to those in the British practice. The follow up interviews revealed the importance of lack of thermal control on occupants’ wellbeing. A balanced appraisal was made of energy performance and users’ health between the two buildings.
Individual thermal control in the workplace and changes in thermal preferences in a day: Norwegian cellular vs. British open plan layoutsThis research suggests that the thermal preference of occupants is subject to change; hence, a particular thermal setting may not be able to constantly satisfy everyone. On the contrary, individual thermal control in the workplace is more likely to increase user comfort and satisfaction. This is examined through environmental measurements, comfort surveys and semi-structured interviews in two office layouts with high and low thermal control. Two Norwegian cellular plan offices that provide each user with control over a window, heating and cooling are compared with two British open plan offices with limited openable windows for users seated around the perimeter of the building. Complementary quantitative and qualitative methodologies and analysis techniques are applied with a particular emphasis on grounded theory and innovative visual analysing technique. Overall rather than a setting an 'optimum temperature' in an endeavour to satisfy all, it is suggested that buildings provide a degree of flexibility to allow occupants to adjust their thermal environment according to their requirements.
Thermal Comfort and Energy: CFD, BES and Field Study in a British Open Plan Office with Displacement VentilationEnergy efficiency and thermal comfort are necessary in designing the workplace. Accurate computational modelling and analysis methods are useful to improve the design, energy consumption and user’s comfort. This study compared the results of combined Computational Fluid Dynamics (CFD) and Building Energy Simulation (BES) with the contextual data collected through a Filed Study of Thermal Comfort (FSTC) regarding user comfort and energy in a workplace. The building was a six storey open plan office in Aberdeen, built in 2011, with displacement ventilation, “very good” BREEAM and “B” energy ratings. Each floor had 175 workstations, 1680m2 office area and approximately 3.5m2 per workstation. Thermal comfort surveys and environmental measurements were applied. The results were compared with the CFD modelling of the ventilation and thermal performance, PMV and BES energy predictions. The simulation results were in good agreement to that of the field data, indicating over 70% slightly cool and 25% neutral. The combination of CFD and BES improved the accuracy of the simulation and provided important information on optimising energy and the thermal environment. This combined simulation is useful and recommended in the design phase to achieve the balance of energy and comfort in the workplace.