Irritative and respiratory symptoms are reported from people working or living in damp and mouldy buildings, but signs of pulmonary involvement have not yet been found. We studied 522 teachers working in 15 primary schools with various degrees of dampness and mould growth. Symptoms, spirometry, CO-diffusion, and bronchial challenge was compared to classification of dampness and mould growth in or outside classrooms.
Authors assessed building-related risk factors for lower respiratory symptoms in office workers. The National Institute for Occupational Safety and Health in 1993 collected data during indoor environmental health investigations of workplaces. Multivariate logistic regression analyses were used to assess relationships between lower respiratory symptoms in office workers and risk factors plausibly related to microbiologic contamination.
This work concerns turbulence levels in a practical operating theatre of a 1200 beds Egyptian modern teaching hospital. The turbulence characteristics were represented by a modified k - epsilon model. Then a series of experimental investigations were preformed in the operating room to investigate the flow and temperature patterns and to assess the validity of the numerical model to be used.
This paper deals with experiments made to test the performance of a personalised ventilation system (PVS). 30 human subjects have participated to the experiment in an office with 6 work stations equipped with a PVS supplying outdoor air.The perception of air quality and the thermal sensation for each participant has been reportedduring their exposure to combinations of 3 levels of personalized air temperature, 4 airflow rates and 3 levels of room air temperature.
30 human subjects participated in a 3 h 45 min. experiment, that took place in an office with mixing ventilation and personalised ventilation systems (PVS).Each person could choose the position of the personal air terminal device, the direction of the air supplied and the flow rate (up to 15 l/s.person).The subjects were exposed to 4 following experimental conditions : PVS supplying outdoor air at 20C, then 23C ; PVS supplying re-circulated room air ; mixing ventilation, without PVS.Results allow to know how the PVS were used by participants (choice of position and flow rate).
Concerning thermal comfort (number one complaint in most offices), the range of occupants needs is very wide. An individual control ventilation system based on VAV (varying air velocity) and integrated into desk was installed in a bank in 20 work areas. The article describes several possible arrangements of this system and mentions air temperatures and flow rates to achieve individual thermal comfort as determined from a preliminary study with a mannequin in laboratory.
This paper examines the performance of five different air terminal devices for personalized ventilation in relation to the quality of air inhaled by a breathing thermal manikin in a climate chamber. The personalized air was supplied either isothermally or non-isothermally (6 C cooler than the room air) at flow rates ranging from less that 5 l/s up to 23 /s. The air quality assessment was based on temperature measurements of the inhaled air and on the portion of the personalized air inhaled. The percentage of dissatisfied with the air quality was predicted.
Experiments with 30 human subjects were performed in an office equipped with personalized ventilation systems (individual control of flowrate and direction) for 6 workers and with different supply air temperatures to analyse perceived air quality and sick building symptoms.
This contribution reports on investigations about the performance of decentralised ventilation units with heat recovery. Such units can be easily installed in individual rooms and therefore offer an interesting alternative to central ventilation units. Nevertheless these units exhibit some problems. Experimental examinations of two commercial decentralised units showed that the real effectiveness of heat recovery was always below 50 % and that considerable leakage between the air ducts can result in poor indoor air quality.
This paper proposes a new personal air-conditioning system, which modifies a common partition used in offices to a partition-type fan-coil unit (PFCU) with inlets and outlets on its surfaces. Chilled water is supplied as the cooling energy, and is delivered to the partitions by pipelines incorporated into the structure. Hence, conventional air conditioning systems using ceiling-based air diffusers for open-plan offices may be dispatched into several small individual systems controlled by the occupants.
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