Operation Of Office Buildings Research Articles

Effect of thermal comfort on occupant productivity in office buildings: Response surface analysis

Thermal environment is one of the main factors that influence occupants' comfort and their productivity in office buildings. There is ample research that outlines this relationship between thermal comfort and occupant productivity. However, there is a lack of literature that presents mathematical relationship between them. This paper presents a research experimental study that investigates effects of indoor environmental quality factors on thermal comfort and occupant productivity. This study was conducted by collecting indoor environmental quality parameters using sensors and online survey for twelve months. Data analysis was done using Response Surface Analysis to outline any mathematical relationship between indoor environmental quality and occupant productivity. The outlined relationships confirmed dependencies of occupant thermal comfort and productivity on various indoor environmental factors. These dependencies include the effect of CO2 concentration, VOC concentration. These relationships were analysed to rank nine indoor environmental parameters as per the degree of effect on occupant thermal comfort and productivity. These findings would help design professionals to design better office design that would improve occupants’ comfort and their productivity. Study results have different implications for professionals working in design, construction and operation of office buildings. It is recommended that design guidelines for office buildings should consider occupant productivity and incorporate recommended range for indoor environmental quality parameters in respective categories and criteria.

Analysis of Natural Ventilation Performance Gap between Design Stage and Actual Operation of Office Buildings

Suitable natural ventilation in office buildings can not only reduce energy consumption of air conditioning, but also improve indoor air quality. In the architectural design stage, the effect of natural ventilation design is mainly simulated by CFD simulation software for indoor air speed, pressure, and age of air, etc.. However, during the actual building operation, the indoor natural ventilation effect will be affected by many factors, such as surrounding buildings, indoor layout, window position and open-close status, human behavior, etc., and the natural ventilation performance between design stage and actual operation is often different. In this paper, a typical office building was selected and FloVENT software was used to quantitatively analyse the influence of surrounding buildings, indoor layout, door/window opening conditions on indoor natural ventilation. Field measurement of indoor air flow rates in typical positions in office were carried out under different circumstances. In order to reduce the instantiate influence of outdoor wind speeds, a new index named Wind Speed Ratio(WSR) is put forward.Through comparative analysis of simulated data and measured data. the gap degree in natural ventilation performance between design stage and operation operation is discussed, and results show that the relative errors of the WSR, which could be considered to reflect the performance gap, are about 78.0%, 28.7% and 150% respectively, under corresponding condition settings of surrounding buildings, indoor layout, and door/window opening.

Formation of the resource saving process in commercial property buildings during the introduction of “green” standards in Russia

The article is dedicated to one of the most essential areas in the construction industry: consideration of the issues related to resource saving, ecologically and economically rational use of natural resources in accordance with “green standards” of the commercial property buildings, offices, in particular. During the operation of office buildings there takes place negative impact on all the components of the environment. Herewith, the first issues considered by the operating organizations are the cost of the facility, safety of technological processes, reliability, durability and operational characteristics, and only then the issues of building environmental friendliness and energy efficiency, the consequences of which are irrational use of natural resources and accumulation of environmental damage. The number of existing systems certifying “green” buildings is insufficient to create a stable human environment. Formation of the resource saving mechanism during the operation of office buildings requires the application of the “green” standards criteria, making it possible to provide results of the stable approaches during the entire operational lifetime of the building. Based on the local and foreign experience in resource saving stimulation under the “green standards” the article provides the estimation criteria making it possible to implement the ecological and economic evaluation of the resource saving mechanism during the operation of office buildings.

Sensitivity analysis of peak and annual space cooling load at simplified office dynamic building model

The focused investigation of building design is necessary to understand and quantify the implication of different design parameters on their energy performance. The design of future buildings is a major challenge, as current designs may be inappropriate in a future with global warming due to climate change impacts. In addition this understanding is necessary to be able to predict timing and profile of future energy demand, which is crucial for the long-term planning of energy infrastructures – particularly electricity. In this paper, the Morris Elementary Effects method is used as a screening method, to identify the key parameters of the design and operation of office buildings that affect the estimation of space cooling peak load and annual energy demand. Internal heat gains, cooling set-point and ventilation rates are identified as the parameters with larger implications for both annual and peak space cooling demand. In future climate scenarios, the magnitude of change of annual space cooling demand is significantly (around five times) larger than the change in the peak demand. Asides from the potential increase of space cooling demand in future scenarios, the sensitivity of the space cooling demand relative to the change in design parameters is potentially much larger.

Adaptive thermal comfort in the offices of North-East India in autumn season

India has a large diversity in climate, socio-cultural setup, and economy, but it aims to provide better amenities and shelter to all by 2022. India is also progressing on the path of high-energy efficiency in the building sector to reduce the energy usage in this sector. In India, decisions are generally made based on energy efficiency as the sole criterion, a fact that holds true for the built environment as well. Studies have shown that a more balanced approach is ‘Adaptive thermal comfort’, which integrates the subject's thermal preferences in the thermal environment, where a subject will experience optimum comfort for most of the time. The climate of North-East India as well as the construction and operation of office buildings is quite different compared to the rest of India. Questionnaire-based field surveys were done in naturally ventilated office buildings at two locations in North-East India (Tezpur and Shillong) in autumn season (September to November 2016). A total of 460 subjects (Tezpur: 295; Shillong: 165) voluntarily participated in this study. Nonlinear regression analysis shows clothing related adaptation by subjects at low and high temperatures, but the maximum adaptation takes place on the cooler side of the thermal sensation scale. Griffiths and linear regression analysis shows that the comfort temperature is 27.3 °C. However, the preferred temperature is 24.5 °C, that is, 2.8 °C lower than the comfort temperature. Logistic regression analysis shows that ∼50% of the fans are operating in offices at 31 °C and almost no fan is in use up to 22.5 °C.