An Approach for Assessing Target Levels for Industrial Air Quality

This paper considers methodologies how desired level, target level, of industrial air quality can be defined taking into account a feasibility issue. The method is based on the health-based risk assessment and the technology-based approach. Because health-based risk estimates at low contaminant concentration regions are rather inaccurate, the technology-based approach is emphasized. The technological approach is based on information on the prevailing contaminant concentrations in industrial work environment and the benchmark air quality attained with the best achievable control technology.

Detailed Experimental Data of Room Airflow with Displacement Ventilation

This paper presents a set of detailed experimental data of room airflow with displacement ventilation. These data were obtained from a new environmental test facility at the Massachusetts Institute of Technology (MIT). The measurements were conducted for three typical room configurations: a small office, a large office with partition, and a classroom. The experiment measured the distributions of air velocity, air velocity fluctuation, and air temperature by omnidirectional hot-sphere anemometers and contaminant concentrations by tracer gas at 54 points in the room.

Computer Effort Saving Methods in Unsteady Calculations of Room Airflows and Thermal Environments

In the unsteady calculations of room thermal environments, two simple and effective methods were introduced to reduce computer efforts through two case studies. One method (method-A) was applied to a passive solar room analysis (caseA) and another method( method-B) was applied to estimation of energy consumption in an air-conditioned room (caseB). In method-A, flow fields are calculated intermittently, namely, calculated every Nta time step while temperature fields are calculated every time step here, Nta≥ 1.

Measurements and Predictions of Room Airflow Patterns using Different Turbulence Models

To evaluate the performance of different turbulence models in room airflow applications measurements in a test room will be compared to numerical calculations. The measurements are taken in a 6 x 4 x 3 m3 room with two heated dummies and a computer. Zero heat flux boundary conditions are achieved by controlling the inner and outer wall temperature. Two different ventilation systems will be examined in order to get momentum and buoyancy driven flow fields. Temperature measurement and Particle Streak Tracking data will be compared to the numerical predictions.

Computational Fluid Dynamics and Building Energy Performance Simulation

An interconnection between a building energy performance simulation program and a Computational Fluid Dynamics program (CFD) for room air distribution will be introduced for improvement of the predictions of both the energy consumption and the indoor environment. The building energy performance simulation program requires a detailed description of the energy flow in the air movement which can be obtained by a CFD program.

A Semi Empirical Flow Model for Low-Velocity Air Supply in Displacement Ventilation

Similar to supply air jets in mixing ventilation this paper describes a comprehensive flow model for displacement ventilation derived from the integrated Navier-Stokes differential equations for boundary layers. A new test method for low velocity diffusers in displacement ventilation is developed based on this new flow model. Contrary to jet flow, it is shown that the only independent variable in the new model is the buoyancy flux.

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