Computational analysis of reduced-mixing personal ventilation jets

Russo, Jackie; Dang, Thong Q.; Khalifa, H. Ezzat

doi:10.1016/j.buildenv.2008.11.005

Cited by 44 publications

(21 citation statements)

References 16 publications

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“…But CFD simulations often use many assumptions, so it is essential to obtain key data about airflow and air quality by means of on-site measurements for validating the CFD results. Russo et al (2009) and Makhoul et al (2013a, b) developed a detailed CFD model to simulate the airflow and particle distribution in a chamber with a seated thermal manikin. On site measurements were conducted for obtaining the boundary conditions and validating the CFD model.…”

Section: Introductionmentioning

confidence: 99%

Strategy for Studying Ventilation Performance in Factories

Zhang

Long

Liu

et al. 2016

Aerosol Air Qual. Res.

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High concentrations of airborne particulate matter in factories can cause serious health problems for workers. One significant reason for these high concentrations is the poor performance of the ventilation systems in workplaces. This investigation developed a strategy that combines computational fluid dynamics (CFD) simulations and on-site measurements to study and improve the ventilation performance in factories. The CFD simulations were able to predict the flow field and particle distributions in factories with complex layouts. The corresponding on-site measurements were performed to provide boundary conditions for the CFD simulations and to obtain key data about airflow and air quality for validating the simulations. This study used the strategy to improve ventilation performance in an automotive parts factory. Three ventilation systems were studied: a roof exhaust system, combined roof exhaust and air recirculation systems, and combined roof exhaust and displacement ventilation systems. This study found that the combined roof exhaust and displacement ventilation systems provided acceptable indoor air quality and thermal comfort levels in the factory.

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Section: Introductionmentioning

confidence: 99%

Strategy for Studying Ventilation Performance in Factories

Zhang

Long

Liu

et al. 2016

Aerosol Air Qual. Res.

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“…By changing the initial conditions (shape and size of the diffuser, uniformity of the initial velocity profile, initial turbulence intensity, etc. ), the velocity distribution field, spread, and entrainment of the personalized flow can be changed over a wide range (Khalifa et al., ; Melikov et al., ; Nastase and Meslem, ; Russo et al, ; Sun et al., ).…”

Section: Advantages Of Advanced Air Distributionmentioning

confidence: 99%

Advanced air distribution: improving health and comfort while reducing energy use

Melikov

2015

Indoor Air

136

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Indoor environment affects the health, comfort, and performance of building occupants. The energy used for heating, cooling, ventilating, and air conditioning of buildings is substantial. Ventilation based on total volume air distribution in spaces is not always an efficient way to provide high-quality indoor environments at the same time as low-energy consumption. Advanced air distribution, designed to supply clean air where, when, and as much as needed, makes it possible to efficiently achieve thermal comfort, control exposure to contaminants, provide high-quality air for breathing and minimizing the risk of airborne cross-infection while reducing energy use. This study justifies the need for improving the present air distribution design in occupied spaces, and in general the need for a paradigm shift from the design of collective environments to the design of individually controlled environments. The focus is on advanced air distribution in spaces, its guiding principles and its advantages and disadvantages. Examples of advanced air distribution solutions in spaces for different use, such as offices, hospital rooms, vehicle compartments, are presented. The potential of advanced air distribution, and individually controlled macro-environment in general, for achieving shared values, that is, improved health, comfort, and performance, energy saving, reduction of healthcare costs and improved well-being is demonstrated. Performance criteria are defined and further research in the field is outlined.

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“…Khalifa et al 37,38 introduced a low-mixing coaxial horizontal PV nozzle that can greatly lengthen the clean air core of a PV jet while maintaining low PV clean airflow rates. The nozzle comprises a primary nozzle delivering fresh clean air surrounded by a concentric annular secondary nozzle providing recirculated air at the same velocity.…”

Section: Introductionmentioning

confidence: 99%

Low-mixing coaxial nozzle for effective personalized ventilation

Makhoul

Ghali

Ghaddar

2013

Indoor and Built Environment

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The aim of this work was to study the performance of a novel coaxial nozzle for personalized ventilation that can be used as an add-on to ceiling diffuser. The coaxial nozzle minimizes air entrainment between the central fresh air stream and the room air. It allows effective delivery of clean air to the breathing zone while the recirculated conditioned air is supplied to the space by the associated ceiling diffuser. Detailed 3-D Computational Fluid Dynamics (CFD) simulations were performed and numerical results on velocity, temperature, and CO 2 concentration fields agreed well with experimentally measured values. The effect of the jet flow rate, temperature, and inclination angle on air quality at the breathing zone of the occupant was then investigated. The proposed coaxial personalized ventilation achieved high air quality in the breathing zone demonstrated by a personal exposure effectiveness of 32% at fresh airflow rate of 10 L s À1 per person. It contributed also to the attainment of temperature differences up to 2 C between the occupant's microenvironment and the rest of the room air leading to considerable energy savings compared to the mixed convection air conditioning.

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Computational analysis of reduced-mixing personal ventilation jets

Cited by 44 publications

References 16 publications

Strategy for Studying Ventilation Performance in Factories

Strategy for Studying Ventilation Performance in Factories

Advanced air distribution: improving health and comfort while reducing energy use

Low-mixing coaxial nozzle for effective personalized ventilation

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