Investigating Indoor Air Quality and Thermal Comfort Using a Numerical                 Thermal Manikin

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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“…[31][32][33] This procedure was repeated until convergence was achieved and the corresponding results were considered converged.…”

Section: Airflow Modellingmentioning

confidence: 99%

Low-mixing coaxial nozzle for effective personalized ventilation

Makhoul

Ghali

Ghaddar

2013

Indoor and Built Environment

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“…In these studies empirical models that calculated the thermal comfort levels based on environmental values, experimentally obtained, were developed and used. Similarly, thermal dynamic models that numerically calculate the compartments thermal comfort mean value in buildings, computational fluids dynamics models that numerically calculate the environmental variables around the occupants and numerical and experimental manikins that evaluate the human thermal response based in thermoregulation principles [1,9,[19][20][21].…”

Section: Occupant's Thermal Comfort Numerical Modelmentioning

confidence: 99%

Numerical Study of the Thermal Efficiency of a School Building with Complex Topology for Different Orientations

Conceição

Lúcio²

2009

Indoor and Built Environment

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In this work a numerical model that simulates the thermal behavior of a building with complex topology and evaluates the indoor thermal and air quality, in transient conditions, is used for a school building thermal project. The program calculates the building surfaces solar radiation field, the building's temperatures, the internal environmental variables, and the occupant's comfort levels.Initially, after the numerical model is validated, the software is used to evaluate the school building's thermal response for four different orientations, either in winter or summer conditions. The work then aims to identify uncomfortable spaces in order to propose, as an example, several solutions that could be introduced for each orientation, that would improve the thermal comfort and air quality levels to which the occupants are subjected, and decrease the building's energy consumption levels. The information obtained from this study could be used to help a designer choose which thermal systems and solutions function best for a preferred school building orientation.

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“…The task ventilation modules are known for providing better thermal comfort, better air quality and lower energy consumption [7][8][9][10][11][12].…”

mentioning

confidence: 99%