English

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.

This paper studies in three-dimension the coupled convective and radiative heat transfer rate from awindow surface with adjacent venetian blind using a commercial CFD code. For this study the window surface was modeled as an isothermal vertical flat plate. The flow patterns (temperature and velocity fields) and convective heat transfer coefficient were investigated for different blade angles (00, 450, -450, 800). Comparisons were made with experimental and other theoretical research.

One of the main arguments supporting the application of the natural ventilation is the reduction inenergy consumption and capacity of the HVAC system. Here several tests of the building with different systems are carried to quantify the differences in capacities and energy consumptions of different solutions for the HVAC system. The tests were carried with the simulation program built in Simulink. To validate the model the measurements were done in Test cell at TU Delft as well as in the real office building.

It is difficult to evaluate the effect of cross ventilation quantitatively, because the indoor environment under cross ventilation is uneven and changes with the outside conditions. In this paper, the decay process of tracer gas is measured in uneven space under cross ventilation, and the property of spatial unevenness is examined by the concentration decay and velocity distribution.

This paper discusses the concept and performance of a naturally ventilated building with a double-skin facade in Tokyo. The building incorporates a hybrid ventilation system (natural ventilation integrated with air-conditioning systems) that makes use of buoyancy forces generated in a vertical airshaft in the center of the building. Field measurements were made in order to evaluate the performance of the double-skin facade during the summer and winter and also the performance of the hybrid ventilation system during the spring and autumn.