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The mixing of different air streams is a process commonly found in air handling systems. One of the most common examples of this process is found in the air handling unit mixing box where outdoor air is mixed with return air. In the adiabatic mixing process, the energy leaving the mixing box equals the energy entering the mixing box. In order to calculate the energy in the mixed air stream, it is only necessary to know the energy in the outdoor and the return air streams. As a result, it is not necessary to consider whether the mixing process is ideal or not.

Using performance characteristics of balanced ventilation units tested in laboratory of CETIAT, a complete ventilation system in an individual house is modelised, in details. Simulations are made with TRNSYS program and hourly dynamic calculations on the heating season, on different French climates (three) and different ventilation configurations (five) : high efficiency or classical balanced system inside the attic or inside the heated volume and simple exhaust ventilation system.

Even though simulation is being increasingly used in design of modern buildings, the full potential of simulation is usually not achieved. To improve building and HVAC system performance, designers usually guess different values of design parameters and then redo the simulation without actual knowing if the guessed value will lead to improvement. This is inefficient and labor intensive. In addition, if the number of design parameters being varied exceeds two or three, the designer can be overwhelmed in trying to understand the nonlinear interactions of the parameters.

We designed a roofed parking lot for a large wholesale market in Sapporo City to protect trucks and cars from snow and rain. Every day, the area attracts a large number of vehicles including trucks. Drivers often leave the engines running for heating in winter and cooling in summer. Exhaust gases poison the air, creating a serious environmental problem. The roof of the new parking lot is equipped with two kinds of chimneys, such as high chimneys to exhaust waste air and low chimneys to supply fresh air.

This paper is concerned with the different methods to present inlet condition for computational fluid dynamics (CFD) simulation of task air conditioning (TAC). The boundary conditions at the supply opening have a strong influence on the flow in the room, and they are, therefore, very important. Usual methods are outlined. Comparison and analysis are then given. The terminal device of TAC is close to people and is relatively large compared to the dimension of the occupied zone. The occupied zone is in the forward flow zone, not return flow zone.

The airflows of rooms are different with the ventilation methods, indoor heat sources distribution, as well as room structures themselves. To understand the features of indoor airflows, engineers and researchers use laboratory tests, CFD techniques and field investigations to probe into the essences of indoor air movements. At present, CFD methods are widely used in predicting space air distributions because of lots of well-known advantages. On the basis of long-term research work, the 3DFLOW codes were developed, which is based on the standard three-dimensional ?

A number of computer simulation case studies have been conducted with the objective of investigating the potential for energy savings in buildings with variable air volume (VAV) systems and demand controlled ventilation (DCV), compared to buildings with conventional constant air volume (CAV) ventilation systems. The simulation systems have been modelled on a modular form, they are generally very detailed and comprehensive, and they have shown to be able to provide very realistic results compared to real world conditions.

The paper presents a numerical study on the airflow within a single-sided heated room with a large vertical opening, with and without interaction of an air curtain. The influence of temperature differences between the heated wall and the exterior on the inflow has been investigated. Also how an air curtain, with different inlet velocities and widths, affect the flow and thermal patterns in the room have been examined. The RNG k-e turbulence model is used for capturing the fluid flow and heat transfer in the building and through the opening.

In this study the performance of a double-skin façade in an office building equipped with a hybrid ventilation system was analyzed. The hybrid ventilation system studied was based on a low-pressure mechanical exhaust system and demand control of ventilati

This study concerns single-sided natural ventilation by using a CFD model, along with analytical and empirical models. The effects of opposing buoyancy and wind forces on ventilation rates and indoor conditions were alos studied in that investigation.