• The Accuracy of Thermal Comfort Zone, ASHRAE Standard 55-2013. CIBSE Technical Symposium 2016

      Shahzad, Sally; Brennan, John; Theodossopoulos, Dimitris; Hughes, Ben; Calautit, John Kaiser; University of Derby; University of Edinburgh; University of Sheffield (CIBSE, 2016)
      This study examined the accuracy of thermal comfort zone (ASHRAE Standard 55-2013) in four offices in Norway and the UK. Thermal environment of the workplace is arranged according to this standard, which predicts to satisfy over 80% of occupants. However, users report dissatisfaction regarding the thermal environment. This study investigated the application of the most widely used thermal comfort standard in practice. Field studies of thermal comfort with recordings of the thermal environment, survey questionnaires and interviews were applied. The results did not agree with the PMV and adaptive prediction models by the ASHRAE Standard 55-2013. The follow up interviews revealed the significance of individual differences in perceiving the thermal environment and the impact of the availability of thermal control on user satisfaction.
    • Adapting Buildings to meet the Energy Challenge

      Calautit, John Kaiser; Hughes, Ben; Shahzad, Sally; University of Sheffield; University of Derby (2014)
    • Design of heat sinks for wearable thermoelectric generators to power personal heating garments: A numerical study

      Soleimani, Zohreh; Zoras, Stamatis; Cui, Yuanlong; Ceranic, Boris; Shahzad, Salome; University of Derby; University of Sheffield (IOP Science, 2020-01-01)
      To mitigate climate change attributed to the built environments, there have been tremendous efforts to improve air conditioning systems in the buildings. The possibility of harvesting body heat as a renewable energy source to power a wearable personal heating system is investigated. The aim of this study is to integrate a wearable personal heating system with a thermoelectric generator (TEG) that harvests the body heat which is used to convert it into electricity. Moreover, the interaction between the TEG configuration and power output is studied. The power generation of TEG system is obtained by COMSOL Multiphysics software. The simulation results concluded that all the four proposed heat sink configurations can improve the power output of the wearable TEG at 1.4 m/s and 3m/s compared to that of the reference model. Furthermore, the perforated and trapezium shapes of heat sinks have a significantly better performance in comparison to conventional heat sinks.
    • 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.
    • Environmental control and sick building syndrome; a comparison between a low carbon open plan and a cellular plan workplace

      Shahzad, Sally; Brennan, John; Theodossopoulos, Dimitris; University of Edinburgh (2013)
      This 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.

      Shahzad, Sally; Brennan, John; Theodossopoulos, Dimitris; Hughes, Ben; Calautit, John Kaiser; University of Derby; University of Edinburgh; University of Sheffield (The University of Sheffield Engineering Symposium, 2015)
      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.
    • The influence of bioclimatic urban redevelopment on outdoor thermal comfort.

      Karakounos, Ioannis; Dimoudi, Argyro; Zoras, Stamatis; Democritus University of Thrace (Elsevier, 2017-11-20)
      One of the greatest environmental challenges for the sustainability of future cities is the mitigation of the urban heat island phenomenon and thus, improvement of outdoor comfort conditions for people. The emphasis of this work is to analyze how mitigation techniques in a dense urban environment affect microclimate parameters and outdoor thermal comfort. The quantitative differentiation of outdoor thermal comfort conditions through bioclimatic urban redevelopment for an area in the city of Serres, Greece is investigated. The main bioclimatic interventions concern the application of cool paving materials, the increase of vegetated areas and the creation of water surfaces. The analysis and comparison are performed for a hot summer day with the ENVI-met model. Software simulations regarding microclimatic and outdoor thermal comfort conditions are performed for the daytime period 06.00–20.00 (14 h) at the height of 1.8 m from the ground. The examined parameters are air temperature, surface temperature and mean radiant temperature (Tmrt). The evaluation of outdoor thermal comfort conditions is conducted using the index PMV (Predicted Mean Vote), adapted for outdoor conditions. The results of simulations are discussed regarding the assessment of bioclimatic interventions.
    • Neutral thermal sensation or dynamic thermal comfort? Numerical and field test analysis of a thermal chair.

      Shahzad, Sally; Calautit, John Kaiser; Aquino, Angelo I.; Nasir, Diana S. N. M.; Hughes, Ben; University of Derby; University of Nottingham; University of Sheffield (Elsevier, 2018-01-31)
      Neutral thermal sensation is considered as the measure of thermal comfort in research, as when participants report feeling neutral regarding the thermal environment, they are considered as thermally comfortable. This is taken for granted, and although a few researchers have criticised the matter, still researchers use thermal sensation and the neutral point to assess the thermal conditions in their studies. This study questions the application of thermal neutrality and consequently poses a question on the findings of all the studies that only rely on it. Field studies of thermal comfort were applied in an open plan office in the UK in the winter of 2014. Participants were provided with a thermal chair and before and after using the chair, their views of comfort were recorded, including the ASHRAE seven point scale of thermal sensation, thermal preference, comfort, and satisfaction. The thermal environment was measured and compared against the ASHRAE Standard 55-2013. In addition, numerical modelling was also conducted to investigated the airflow and thermal distribution around the proposed thermal chair with a seated occupant. The results indicated that overall, 72% of the respondents, who did not feel neutral (thermal sensation) before or after using the thermal chair reported to feel comfortable and 65% reported to be satisfied. The results indicated that a neutral thermal sensation does not guarantee thermal comfort of the occupants and that thermal comfort is dynamic and other thermal sensations need to be considered. This study recommends the use of multiple methods (e.g. thermal, preference, decision, comfort, and satisfaction) to assess thermal comfort more accurately. Also, it questions the findings of any research that solely relies on thermal sensation and particularly on the neutral thermal sensation to assess thermal comfort of the occupants. The results also emphasised the importance of the application of numerical modelling in evaluating the thermal performance of the chair.
    • Quantitative vs. qualitative methodologies to investigate environmental control in the workplace: neutral thermal sensation and thermal environmental intention

      Shahzad, Sally; Brennan, John; Theodossopoulos, Dimitris; University of Edinburgh (2013)
      This study compares the application of qualitative and quantitative methods to investigate user comfort and environmental control in the workplace. This is examined by environmental measurement and user satisfaction in two workplaces with respectively low and high levels of individual environmental control. An open plan office in Scotland is selected with automatic displacement ventilation, where users have access to limited windows. In contrast, a cellular plan office in Norway is chosen that provides every user with control over a window, in addition to the ability to adjust heating and cooling. Complimentary quantitative and qualitative methodologies are applied with particular emphasis on Grounded Theory methods. Questionnaire, environmental measurements and semi-structured interviews are used. A new visual recording method is applied to analyse the subject in its context qualitatively. Information regarding all users and their environment is applied as colour codes to floor plate layouts. The results are compared with the quantitative analysis. The study examines the significance of applying a qualitative method to question the ‘Neutral Thermal Sensation’ and expand on the importance of the ‘Thermal Environmental Intention’. This paper suggests that the quantitative appraisal could be associated with a risk of misjudgement.
    • A review of critical framework assessment matrices for data analysis on overheating in buildings impact.

      Adlington Martin; Ceranic, Boris; University of Derby (World Academy of Science, Engineering and Technology, 2017-11)
      In an effort to reduce carbon emissions, changes in UK regulations, such as Part L Conservation of heat and power, dictates improved thermal insulation and enhanced air tightness. These changes were a direct response to the UK Government being fully committed to achieving its carbon targets under the Climate Change Act 2008. The goal is to reduce emissions by at least 80% by 2050. Factors such as climate change are likely to exacerbate the problem of overheating, as this phenomenon expects to increase the frequency of extreme heat events exemplified by stagnant air masses and successive high minimum overnight temperatures. However, climate change is not the only concern relevant to overheating, as research signifies, location, design, and occupation; construction type and layout can also play a part. Because of this growing problem, research shows the possibility of health effects on occupants of buildings could be an issue. Increases in temperature can perhaps have a direct impact on the human body’s ability to retain thermoregulation and therefore the effects of heat-related illnesses such as heat stroke, heat exhaustion, heat syncope and even death can be imminent. This review paper presents a comprehensive evaluation of the current literature on the causes and health effects of overheating in buildings and has examined the differing applied assessment approaches used to measure the concept. Firstly, an overview of the topic was presented followed by an examination of overheating research work from the last decade. These papers form the body of the article and are grouped into a framework matrix summarizing the source material identifying the differing methods of analysis of overheating. Cross case evaluation has identified systematic relationships between different variables within the matrix. Key areas focused on include, building types and country, occupants behavior, health effects, simulation tools, computational methods.
    • Thermal Comfort and Energy: CFD, BES and Field Study in a British Open Plan Office with Displacement Ventilation

      Shahzad, Sally; Calautit, John Kaiser; Hughes, Ben; Brennan, John; Theodossopoulos, Dimitris; University of Derby; University of Sheffield; University of Edinburgh (2016)
      Energy 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.
    • Thermal comfort and indoor air quality analysis of a low-energy cooling windcatcher.

      Calautit, John Kaiser; Aquino, Angelo I.; Shahzad, Sally; Nasir, Diana S. N. M; Hughes, Ben Richard; University of Sheffield; University of Derby (Applied Energy, 2016)
      The aim of this work was to investigate the performance of a roof-mounted cooling windcatcher integrated with heat pipes using Computational Fluid Dynamics (CFD) and field test analysis. The windcatcher model was incorporated to a 5m x 5m x3 m test room model. The study employed the CFD code FLUENT 15 with the standard k-ɛ model to conduct the steady-state RANS simulation. The numerical model provided detailed analysis of the airflow and temperature distribution inside the test room. The CO2 concentration analysis showed that the system was capable of delivering fresh air inside the space and lowering the CO2 levels. The thermal comfort was calculated using the Predicted Mean Vote (PMV) method. The PMV values ranged between +0.48 to +0.99 and the average was +0.85 (slightly warm). Field test measurements were carried out in the Ras-Al-Khaimah (RAK), UAE during the month of September. Numerical model was validated using experimental data and good agreement was observed between both methods of analysis.