The authors have assessed a new method whose aim is to measure particles infiltrations in individual homes. That method consists in applying a recursive mass balance model to continuous indoor and outdoor concentration measurements . But this method does not allow the estimation of air exchange rate.
This study presents a prediction of the space-time evolution of airborne pollutant dispersion following the accidental rupture of a containment enclosure (fume cupboard, glove box, pressurized gas duct etc.). Gas tracing experiments have been carried out along with multidimensional simulations using CFD tools. Comparisons between experimental and numerical results largely agree.
The Carbon dioxide (CO2) and cubic-feet-per-minute (cfm) based methods are used to verify the amount of outdoor-air ventilation being delivered to building occupants , and to check that the minimum ventilation required by ANSI/Ashrae standard 62 is being provided too. Data quality varies significantly between CO2 and cfm based ventilation assessments. In that paper the advantages and drawbacks of each method are discussed.
This article presents a ventilation strategy that combines ceiling exhausts, bench exhausts, and ceiling radiant-cooling panels . It appears to provide very good thermal conditions and large energy savings for a typical laboratory. Simulations results are presented.
Draft and non-uniform fresh air distribution are common problems in winter ventilation, especially for large animal buildings. Thermal-based anemometers have difficulties in accurately measuring non-isothermal and low-speed indoor airflow. A new technology, particle tracking velocimetry (PTV), which uses particles and their images to study indoor airflow, can overcome the traditional limitations in indoor airflow measurement. A PTV system was used to characterize indoor airflow in a full-scale ventilated room under nonisothermal ventilation conditions.
In this paper, airflow in a slot-ventilated enclosure is numerically studied at Reynolds number 5024, which is based on inlet height and mean velocity at the inlet. Both Reynolds averaged Navier-Stokes (RANS) simulation and large eddy simulation (LES) are applied, and numerical results are
Currently accepted best design practice for controlling airborne particulates in the hospital operating room relies on air flow type (laminar) and direction (down from ceiling). This is typically in the form of large arrays of laminar diffusers. These arrays are limited, or impacted, by deltaT and the need to have other ceiling-mounted equipment in the operating room. The industry could benefit from a scalable pre-engineered system that overcomes these inherent limitations. Such systems could be qualified by actual microbial testing
Experiments with a fan-driven convector used for both heating and cooling are described in this paper. Only the cooling situation is considered. The convector is positioned in the upper corner of the room, and from there the cold air is let out through the device along the ceiling. The airflow coming from the diffuser is partly controlled by the momentum flow and partly from gravity forces, where the thermal load in the room and the temperature difference between room air and supply
The issue of assessing existing buildings in terms of their vulnerability to extreme man-made intentional threats has acquired great urgency in recent years. Several federal and professional agencies, as well as individuals, have been working on this issue, and a number of analytical methods and tools have been suggested and developed. The field has reached a level of maturity where it is now necessary to synthesize existing work and define the types of specific consensus and research areas that need to be studied from the buildings perspective.
An experimental study and model analysis were performed to assess the effectiveness of commercially available in-room air cleaners in minimizing the impact of a hazardous aerosol released in a building. Two air cleaners were evaluated: a HEPA-type air cleaner and an electrostatic
precipitator.
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