Application of numerical simulation in assessment of microclimatic condition in urban areas

The proposition of an assessment method of wind condition in urban structures is presented in the paper. In the second part of the paper two virtual residential districts with different urban organisation have been investigated. An assessment model used to examine wind conditions in selected urban organisation structures defines quantitative and qualitative features of the study area. Two elements of the urban environment, wind conditions and urban development, are evaluated.

Predicting natural ventilation in a two-zone building driven by combined forces

Natural ventilation relies on less controllable natural forces so that it needs more artificial control, and thus its prediction, design and analysis become more important. This paper presents both theoretical and numerical simulations for predicting the natural ventilation flow in a two-zone building with multiple openings which is subjected to the combined natural forces. To our knowledge, this is the first analytical solutions obtained so far for a building with more than one zones and in each zone with possibly more than 2 openings.

Numerical value research on bake-out technology with dilution ventilation for building materials

Bake-out with dilution ventilation is a potential technology that can shorten emission cycle of indoor VOCs and other hazardous gas, and then reduce indoor environment pollution brought forward by building materials. This technology based on characteristic that chemical substance of building materials is easier to emit under high temperature. This paper used numerical value method to compute TVOC removal amount under different operation conditions and concentration changes indoor during bake-out exhaust dilution process.

CFD simulation of inter-flat air cross-contamination—A possible transmission path of infectious diseases

The objective of this study is to investigate the possible transmission mechanism of inter-flat air cross-contamination under the condition of singlesided natural ventilation. In high-rise residential building with flush windows on the same side, the air pollutants can diffuse from lower flat to adjacent upper flat in the vertical direction related to the interflat air flow through open windows caused by the temperature difference between the indoor air and the air outside of the windows.

Human health damages due to indoor sources of radon in life cycle assessment of dwellings

A methodology was developed to calculate health damages due to exposure to radon emitted to indoor air for use in dwelling life cycle assessment. Fate factors were calculated based on dose conversion factors and effective outgoing airflows. Effect factors were calculated from linear relationship between dose and cancer cases. Damage factors are expressed in terms of disability adjusted life years (DALYs).

Application of a whole room indoor air quality (IAQ) model

In a previous study, a whole room IAQ model consisting of multi-phase emission/sorption model for wall materials and room volume mass balance model catering for practical ventilation schemes was developed. The interactions between volatile organic compounds (VOCs) and building materials composing different building components can thus be modeled based on fundamental mass transfer theories. In the present study, the effects of various ventilation strategies and outdoor source on the indoor gas phase VOC concentration are investigated by simulating different building scenarios.

Numerical simulation and experiment research of air organization in air- conditioned passenger car

By k− ε  turbulence model, the indoor air fluid flow and heat transfer conjugated programs in the YZ25K air-conditioned passenger car are solved with SIMPLE algorithm. The effect of solar radiation and body heat is taken into account and these auxiliary heat flows are the source terms of the energy equation.

Changes of the micro-climate and building cooling load due to the green effect of a restored stream in Seoul, Korea

Cities all over the world have been warming up in the summer over the years. Seoul, Korea, is also an example of how a city was transformed into an urban heat island. Green areas produce social, economical and environmental benefits in highly populated urban areas. This study is to investigate the micro-climate changes and urban-scale cooling load reduction by the recently restored Cheonggye stream, also known as Cheonggyecheon, in Seoul, Korea.

Simulation-based performance assessment of slit-type ventilation system for domestic buildings in Korea

The airtight window system adopted in highrise residential buildings or residential-commercial complexes recently in Korea gives rise to poor ventilation, deterioration of Indoor Air Quality (IAQ) and the overloading of cooling systems during the summer season. To address these problems, a slittype ventilation system has been developed. This study is to investigate the performance of the slit-type ventilation system using computer simulation. A thermal model coupled with an air flow network model which represents an apartment with an underfloor heating system was created.

Quantifying the performance of natural ventilation

Increasing attention is being paid to natural solutions to building design, e.g. mixed-mode (or hybrid) ventilation, or increased use of daylight. However, the issue of quantifying performance is less clear: is an hour of no ventilation or 5 minutes of acute glare every so often acceptable?

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