• Computational and field test analysis of thermal comfort performance of user-controlled thermal chair in an open plan office

      Shahzad, Sally; Calautit, John Kaiser; Hughes, Ben; Nasir, Diana S. N. M.; University of Derby; University of Sheffield (Applied Energy, 2016)
      In this study, a thermal chair prototype was developed that allowed individual control over the temperature settings of the backrest and the seat. Limited research is focused on different methods to provide individual user control over the thermal environment. This is particularly difficult to achieve in an open plan office setting, where changing the temperature in one area directly influences the comfort and satisfaction of other occupants seated nearby. In this study, the application of the thermal chair was analysed using Computational Fluid Dynamics (CFD) and field-test analysis in an open plan office in Leeds, UK during winter. The results of the CFD model indicated an improvement in local thermal comfort of the user,. The CFD analysis provided detailed analysis of the thermal distribution around a siting manikin and was used to design and construct the thermal chair. the results of the field data survey indicated a great improvement in users’ comfort (19%) and satisfaction (35%). This study concludes that local thermal control of the occupant improves their overall thermal comfort. It recommends further work to optimise the design of the thermal chair and also to improve the modelling for better predictions.
    • Energy and Comfort in Contemporary Open Plan and Traditional Personal Offices

      Shahzad, Sally; Theodossopoulos, Dimitris; Hughes, Ben; Calautit, John Kaiser; Brennan, John; University of Derby; University of Edinburgh; University of Sheffield (2016-03-05)
      Two office layouts with high and low levels of thermal control were compared, respectively traditional cellular and contemporary open plan offices. The traditional Norwegian practice provided every user with control over a window, blinds, door, and the ability to adjust heating and cooling. Occupants were expected to control their thermal environment to find their own comfort, while air conditioning was operating in the background to ensure the indoor air quality. In contrast, in the British open plan office, limited thermal control was provided through openable windows and blinds only for occupants seated around the perimeter of the building. Centrally operated displacement ventilation was the main thermal control system. Users’ perception of thermal environment was recorded through survey questionnaires, empirical building performance through environmental measurements and thermal control through semi-structured interviews. The Norwegian office had 35% higher user satisfaction and 20% higher user comfort compared to the British open plan office. However, the energy consumption in the British practice was within the benchmark and much lower than the Norwegian office. Overall, a balance between thermal comfort and energy efficiency is required, as either extreme poses difficulties for the other.
    • Energy efficiency and comfort in the workplace: Norwegian cellular and British open plan

      Shahzad, Sally; Brennan, John; Theodossopoulos, Dimitris; Hughes, Ben; Calautit, John Kaiser; University of Derby; University of Edinburgh; University of Sheffield (2015)
      Two office layouts with high and low levels of thermal control were compared, respectively Norwegian cellular and British open plan offices. The Norwegian practice provided every user with control over a window, blinds, door, and the ability to adjust heating and cooling. Occupants were expected to control their thermal environment to find their own comfort, while air conditioning was operatingin the background to ensure the indoor air quality. In contrast, in the British office, limited thermal control was provided through openable windows and blinds only for occupants seated around the perimeter of the building. Centrally operated displacement ventilation was the main thermal control system. Users’ perception of thermal environment was recorded through survey questionnaires, empirical building performance through environmental measurements and thermal control through semi-structured interviews. The Norwegian office had35% higher user satisfaction and 20% higher user comfort compared to the British open plan office. However, the energy consumption in the British practice was within the benchmark and much lower than the Norwegian office. Overall, a balance between thermal comfort and energy efficiency is required, as either extreme poses difficulties for the other.
    • Energy Efficiency and User Comfort in the Workplace: Norwegian Cellular vs. British Open Plan Workplaces

      Shahzad, Sally; Brennan, John; Theodossopoulos, Dimitris; Hughes, Ben; Calautit, John Kaiser; University of Derby; University of Edinburgh; University of Sheffield (2015)
      Two office layouts with high and low levels of thermal control were compared, respectively Norwegian cellular and British open plan offices. The Norwegian practice provided every user with control over a window, blinds, door, and the ability to adjust heating and cooling. Occupants were expected to control their thermal environment to find their own comfort, while air conditioning was operatingin the background to ensure the indoor air quality. In contrast, in the British office, limited thermal control was provided through openable windows and blinds only for occupants seated around the perimeter of the building. Centrally operated displacement ventilation was the main thermal control system. Users’ perception of thermal environment was recorded through survey questionnaires, empirical building performance through environmental measurements and thermal control through semi-structured interviews. The Norwegian office had35% higher user satisfaction and 20% higher user comfort compared to the British open plan office. However, the energy consumption in the British practice was within the benchmark and much lower than the Norwegian office. Overall, a balance between thermal comfort and energy efficiency is required, as either extreme poses difficulties for the other.
    • Thermal Comfort and Energy Efficiency in a Naturally Ventilated Office: CFD, BES and a Field Study

      Calautit, John Kaiser; Shahzad, Sally; Hughes, Ben; Brennan, John; Theodossopoulos, Dimitris; University of Sheffield; University of Derby; University of Edinburgh (Nova Publishers, 2015)
      The energy crisis drives the design of the workplace towards passive systems, such as natural ventilation. The design of the ventilation system influences the energy demand of the building and comfort of the user. In order to improve the design, optimise the energy performance, predict and improve users’ comfort, the application of accurate computational modelling and analysis techniques are essential. This study reviews the advances in thermal comfort modelling and energy analysis of the workplace using Computational Fluid Dynamics (CFD) and Building Energy Simulation (BES). This is followed by a case study of CFD-BES analysis of energy and thermal comfort of a practice example of a naturally ventilated office. This is a three storey building with an open plan layout in the UK and the office area of 3000 m2, including 375 workstations. It was awarded by the British Council for Offices, received an ‘excellent’ BREEAM rating and 10 out of 10 Environmental Performance Indicator (EPI) rating. The office is naturally ventilated with manually and mechanically operated windows and a stack effect through the vents above the atrium. Furthermore, environmental measurements and comfort surveys are applied in the case study buildings.