English

The main goal of this work is the modeling of the flow field and temperature distribution in thekitchen of a house where natural ventilation techniques were implemented. The Fluent 6.1 commercial CFD software was used. The k- e turbulence model and the Boussinesq approximation for buoyancy were employed. The heat released from a water heater in continuous operation dictates the temperature distribution in the kitchen. Several simulations were performed by varying the boundary conditions and seeking agreement with the available experimental data.

In order to clarify whether a combination of designs is optimal, design elements are divided intodesign variables and random variables in the inquiry process for the optimal design. Design variablesrelated to the model are selected by a genetic algorithm, and random variables related to outdoor condition are selected by the moment method. The whole process of optimization consisted of a two-step procedure to reduce the calculation loads for finding the optimal solution. This study carried out a simple analysis using a coarse mesh considering the calculation loads in the first step.

Evaluating naturally ventilated buildings for performance is a difficult task, often relying oncomputer simulations and modeling to assess thermal comfort and airflow issues. This paper presents the long and short term monitoring procedures and data devised to determine the overall building performance of a naturally ventilated office building in the United Kingdom.

Large spaces with high thermal loads and high air flow rates air conditioned by displacement flowsometimes require air supply through the raised floor. One favoured solution is to cover the perforated floor by an air permeable carpet. Successful solutions of this type of air outlets exist in many buildings in Germany since many years and work successfully. But design and installation require some knowledge which partly may have been lost in recent years. In newer buildings many difficulties appeared.

Underfloor air distribution (UFAD) strategy is gaining popularity during the last years, howeverresearches about the performance of such systems still need to be deepened.One of the appreciated features of this technology is the use of an underfloor plenum below a raised floor. This plenum is used to distribute the conditioned air in the rooms and makes possible to avoid large air ducts to be installed.

Arthur Rosenfeld cited a study showing that the huge link between IAQ and productivity in anoffice building and the serious initiative to improve indoor air quality will have a tremendous return. This study attempts to analyze the working spaces with different variances. The chamber measurements in the laboratory constructed in Shu-Te University will be taken, and the numerical simulation using CFD techniques will also be applied. The results from both should be compared. The different inlet layout of HVAC system, especially the UFAD system, and the boundary conditions will be discussed.

This paper reports experimental measurements on the diffusion of confluent jets thatform a wall jet. The experiments were carried out at a fixed air flow rate and fixed temperaturedifference between the supply and room air in the cooling mode. Based on these experiments, theresults presented show the behaviour of the wall confluent jet in the form of velocity profiles, thespreading ratio of jet on the wall, etc. The empirical equations derived are compared with othertypes of air jets, such as the free confluent jet, free plane wall jet, and free plane jet.

This paper deals with how to visibly render the thermal climate in the design and presentationtools used by different participants in the building process. The focus is on those ventilation/coolingsystems where cool air is supplied directly into the occupied zone and therefore have a potential ofgenerating a volume close to the device with poor comfort. This volume could be described as a spreading bubble. In the paper a practical procedure for rendering the spreading bubble is presented. This is achieved in a number of steps.

In this work a numerical model, that simulates the buildings thermal response and evaluates theinternal air quality in transient conditions, is validated and used. This multi-nodal model calculates notonly the buildings temperatures and the air water vapour and contaminants mass, but also the air relative humidity inside the spaces, the solar radiation inside and outside building surfaces, the heat and mass convection coefficient, the views factors between internal surfaces, the heat and mass fluxes and the global thermal comfort level.

The paper describes the use of a synthesis in thermal network models. Simulation methods areusually based on an analysis when the optimal solution is found by means of iteration process. Presented method is developed in a frequency domain for models that are built as electric circuits. General description of the method with used equations is given. The application is demonstrated in a case study when a cooling power for one room in light-weight building is found. Resultant values are time dependent internal cooling load that ensures desired inside air temperature during summer day.