Study of the impact of operation distance of outdoor portable generators under different weather conditions
The US Centres for Disease Control and Prevention has reported that up to half of non-fatal carbon monoxide (CO) poisoning incidents during the hurricane seasons in 2004 and 2005 involved generators operated outdoors but within 7 ft of the home. Current guidance for safe operating distances of generators is often neither specific nor consistent. A study was conducted to examine the impact of generator distance on indoor CO exposure. The study was based on computer simulations of CO transport outdoors and subsequently into a generic two-storey house. This paper presents the simulation results when using an indoor air qualit...
Source: Indoor and Built Environment - November 11, 2014 Category: Occupational Health Authors: Wang, L., Emmerich, S. J., Lin, C.-C. Tags: Original Papers Source Type: research
Thermal and non-thermal germicidal effects of microwave radiation on microbial agents
To assess possible applications of evaporative humidifier elements of air-conditioning systems, the germicidal effect of microwave irradiation on fungal spores (e.g. Cladosporium herbarum and Fusarium solani), vegetative bacteria and bacterial spores (e.g., Bacillus subtilis) was investigated by this study. A general purpose microwave oven and a specifically assembled microwave source placed in a 2.45 GHz magnetron were used. Initially, the optimal radiation output power and exposure time were determined to achieve the desired germicidal effects using both wet and dry sample filters. The study also investigated whether the...
Source: Indoor and Built Environment - November 11, 2014 Category: Occupational Health Authors: Kang, Y., Kato, S. Tags: Original Papers Source Type: research
Corrections for minimizing solar profile prediction errors and methods for preventing direct glare on the workplane in blind control
As a means of improvement of environmental comfort in buildings with blind control, the objective of this study is to minimize solar profile prediction error for the purpose of preventing direct glare caused by the sunlight inlet in blind control. During the process of solar profile prediction, the main variables that cause prediction error of the solar profile were defined and problems from the prediction error were analysed. Surface orientation and time are significant factors that may cause error and glare during blind control. This research proposes and evaluates the correction methods and control strategy to minimize ...
Source: Indoor and Built Environment - November 11, 2014 Category: Occupational Health Authors: Seong, Y.-B., Yeo, M.-S., Kim, K.-W. Tags: Original Papers Source Type: research
Exploring the road less travelled in energy reduction: More comfort with less energy, but is comfort always essential?
(Source: Indoor and Built Environment)
Source: Indoor and Built Environment - November 11, 2014 Category: Occupational Health Authors: Ucci, M. Tags: Editorial Source Type: research
Determination of the emissions of volatile organic compounds from oriented strand boards and evaluation by the German AgBB scheme
There has been an increasing use of oriented strand boards (OSBs) for the construction of floors, ceilings and walls of buildings. In Germany and other European countries, OSBs are mainly produced from pine wood (Pinus sylvestris). In response to complaints about the odour and irritation of mucous membranes in connection with the use of OSBs, samples of OSBs were bought from do-it-yourself stores to test their volatile organic compound (VOC) emissions by using emission test chambers. The boards emitted predominantly monoterpenes, aldehydes, acids and acetone. Aldehydes are generated during the production process by the oxi...
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Wilke, O., Wiegner, K., Scheffer, H., Brodner, D., Kalus, S. Tags: Original Papers Source Type: research
Integrated numerical approach of computational fluid dynamics and epidemiological model for multi-scale transmission analysis in indoor spaces
The indoor environment can play a significant role in the airborne transmission of diseases, such as those caused by influenza virus and tuberculosis virus. The airborne route of transmission is considered to be critically important for evaluating the risk to occupants' health due to exposure to these contaminants. In this paper, an analytical procedure coupling with the computational fluid dynamics (CFD)-based prediction has been proposed for the determination of the unsteady and non-uniform contaminant concentration distribution within an indoor environment. A basic epidemiological model (here, SIR model) is used to eval...
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Ito, K. Tags: Original Papers Source Type: research
Electricity energy trends in Hong Kong residential housing environment
This study examines the electricity consumption in apartments and communal areas for both public and private housing in Hong Kong. A tool based on Monte Carlo sampling has been developed to predict residential electricity consumption in terms of housing type, occupant load per apartment (tenant) and gross floor area per building (communal). The residential electricity demand forecasts for Hong Kong show that substantial energy savings (>670 GWh yr–1) can be achieved over the next decade through adjusting the mix of housing types and reducing communal energy use. The outcome of this study is useful for urban policy...
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Cheung, C. T., Mui, K. W., Wong, L. T., Yang, K. C. Tags: Original Papers Source Type: research
A modified tracer-gas decay model for ventilation rate measurements in long and narrow spaces
This study has proposed a modified tracer-gas-concentration decay method that combines the multi-zone technique with the genetic algorithm to determine ventilation rate in such spaces. To validate the proposed method, the investigation utilized both the modified decay method and the traditional decay method to numerically measure the ventilation rate in an MD-82 aircraft cabin by computational fluid dynamics technique. The results showed that the modified tracer-gas-concentration decay method can significantly improve the accuracy and reliability of the ventilation rate measurements in such a large, long, and narrow space....
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Chao, J., Mu, X., Xue, Y., Li, F., Li, W., Lin, C.-H., Pei, J., Chen, Q. Tags: Original Papers Source Type: research
Airborne fungal profiles in office buildings in metropolitan Adelaide, South Australia: Background levels, diversity and seasonal variation
This study examined viable fungi in 128 air samples (89 indoor: 39 outdoor) from office buildings in Adelaide, South Australia, which has an arid Mediterranean climate. Results across four consecutive seasons show that the viable airborne fungal concentrations in indoor air were on average 75% lower than those in outdoor air. A seasonal influence was noted with higher fungal levels in autumn and summer compared with winter and spring. The most common culturable airborne fungi, across all seasons and conditions, were Penicillium, Aspergillus, Cladosporium and Alternaria. A weak correlation between fungal spore concentration...
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Taylor, M., Gaskin, S., Bentham, R., Pisaniello, D. Tags: Original Papers Source Type: research
Performance testing of engineering controls of airborne infection isolation rooms by tracer gas techniques
The ventilation performance of airborne infection isolation rooms (AIIRs) was assessed in three Finnish hospitals by examining the air change rate, contaminant removal efficiency and leakage of contaminants outside the isolation room by using tracer gas techniques. Results showed that infectious agents can escape from the AIIR during egress despite high ventilation rates in the AIIR and anteroom (air change rate, 4–24 h–1) and the pressure difference between the AIIR and corridor was –0.2 to –29 Pa. The control of impurities was often ineffective due to inappropriate direction of air flows and air m...
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Kokkonen, A., Hyttinen, M., Holopainen, R., Salmi, K., Pasanen, P. Tags: Original Papers Source Type: research
Indoor environment and respiratory symptoms among children under five years of age in a peri-urban area of Abidjan
Children who spend more time indoors at home could become vulnerable to respiratory illnesses due to indoor pollution. There is little documentation on this major threat to public health in Côte d’Ivoire, where 70% of the population uses biomass as a home energy source. As a part of an EcoHealth project, factors associated with the prevalence of respiratory symptoms among children under five years of age were studied in a peri-urban neighbourhood north of Abidjan. From May to July 2010, a transdisciplinary team administered a questionnaire and an observation checklist to collect data on the physical quality of ...
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Sackou, J. K., Oga, S. A., Tanoh, F., Houenou, Y., Kouadio, L. Tags: Original Papers Source Type: research
Numerical analysis to determine the performance of combined variable ceiling and floor-based air distribution systems in an office room
This study analyses the performance characteristics of combined variable ceiling and floor-based air distribution systems in an office room using a numerical method to optimize the level of thermal comfort and indoor air quality. To validate the computational fluid dynamics simulations, temperature, air velocity and CO2 concentration were measured and compared. The simulation results of various combinations of ceiling and floor-based air distribution systems show that the exhaust should be located above the occupant and the window in summer; due to the large thermal plume as heat sources that could be generated by the wind...
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Park, D. Y., Chang, S. Tags: Original Papers Source Type: research
Approach to identifying a sudden continuous emission pollutant source based on single sensor with noise
Accidental pollution events often threaten people’s health and lives, and it is necessary to identify a pollutant source rapidly so that prompt actions can be taken. An approach to identify a sudden continuous emission pollutant source based on the sensor measurement noise distribution model is developed in this paper. This approach attempts to locate a source in a steady velocity field while considering the impact of sensor measurement noise. This approach identifies a source by comparing the characteristic distance of the sensor-measured concentration sequence and the multiple hypothetical measured concentration se...
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Pang, L., Wang, W., Qu, H., Hu, T., Zhang, Y. Tags: Original Papers Source Type: research
A coupled computational fluid dynamics and analytical model to simulate airborne contaminant transmission in cabins
A coupled computational fluid dynamics (CFD) and analytical model is presented for accurate and time-efficient prediction of transient airborne contaminant transmission in full-length airliner cabins. The CFD model was used at locations near the contaminant source, while the analytical model was used for the rest of the cabin. The CFD and analytical model coupling used two different methods for solving the transient contaminant flux. One method forced an outflow condition at the interface of the CFD; this analytical model is less accurate but easier to implement in commercial CFD software. The other method that iteratively...
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Mazumdar, S., Long, Z., Chen, Q. Tags: Original Papers Source Type: research
Satisfaction and perception of residents towards bioclimatic design strategies: Residential college buildings
Successful implementation of bioclimatic design strategies not only reduces energy use, but more importantly increases the resident’s satisfaction. A post-occupancy evaluation, a form of survey method, was used in assessing the satisfaction and perception of residents in two residential colleges, at the University of Malaya, Kuala Lumpur. Both Case Study A (CS-A) and Case Study B (CS-B) represent the uppermost and moderate implementation of bioclimatic design strategies. The results showed that 414 questionnaires were retrieved fully filled by occupants at CS-A while 155 respondents from CS-B returned their questionn...
Source: Indoor and Built Environment - October 6, 2014 Category: Occupational Health Authors: Jamaludin, A. A., Keumala, N., Ariffin, A. R. M., Hussein, H. Tags: Original Papers Source Type: research
