model

A Local Dynamic Similarity Model, applicable to dynamic similarity of cross-ventilation, has been applied to outflow openings. Cross-ventilation performance at the openings on the outflow side has been evaluated, and the structure of air flows around the outflow openings has been studied by LES and wind tunnel experiments. It was found that LES reproduces the wind tunnel experiment results fairly well, such as the extensive increase of discharge coefficient in a small region where dimensionless room pressure, PR*, is low.

To evaluate the property of cross ventilation quantitatively, it is important that the calculated air flow field is compared with measurement. In this paper, the air flow field in the wind tunnel of the Building Research Institute of Japan (BRI) was calculated by CFD analysis using the standard k- e model, and the adequacy of the calculation was examined by comparison with measured values.

The effect of indoor gamma dose rate, permeability of soil, substructure, and ventilation habits of inhabitants were studied using data of 84 low rise residential houses collected in an area of enhanced indoor radon concentration. The radon concentrations varied from 30 to more than 5000 Bqm-3. Cross-tabulation, comparisons of means and multiplicative models were used to test the significance of the effects. In this study a quite high percentage of explained variation R2 - 68% - was found. It was found that the most important factors were the substructure and the permeability of the soil.

According to its location, thermal mass can be approximately classified into two types: external and internal. Internal thermal mass, such as furniture and purpose-built internal concrete partitions, does not expose to ambient temperature directly, while external thermal mass, such as walls and roofs, expose directly to ambient temperature variation. A virtual sphere method for modelling thermal mass is introduced and its application in building thermal mass design is discussed.

Relative humidity is one of the most important parameters which have an influence on human comfortand indoor air quality. Materials exposed to the air can absorb and desorb moisture and thereforeinfluence the relative humidity level. However hygroscopic materials are not always taken into accountin building energy performance simulation codes. The objective of presented work was to improvepredictions of the indoor relative humidity in a well known energy simulation tool TRNSYS.

For the heating of buildings occupied on a discontinuous basis, intermittent heating control devices are used. This article presents one which incorporates advanced automatic control techniques (predictive temperature control and adaptation of the internal model). The results obtained are compared with those achieved using standard control devices. They are validated on the installation used to determine the initial settings and on slightly different installations in order to compare their robustness with respect to the various characteristics of the heating loop and of the building.

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.

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.