A procedure for evaluating natural ventilation potential of urban sites.

This paper describes synthetically the work carried out by the Polytechnic University of Turin within the CE-funded .Research project PRECiS, aimed at valuating the effect of urban form on heating and cooling energy saving potential. A sens1tlv1ty analysis based on the parameter urban wind pressure drag was performed using the thermal simulation program ESP-r. The methodology used and a first set of results are presented.

Evaluation of vertical solar air collectors for natural ventilation using integrated and CFD models.

Vertical solar-air collectors that are used for providing natural ventilation can be a viable solution in buildings where higher ventilation rate requirements for better indoor air quality cannot be met by traditional natural ventilation methods. Indoor air quality problems have been experienced in Portuguese school buildings where a study revealed that the C02 concentrations in classrooms in winter were higher than the recommended health limits. To improve the environment in these classrooms, solar-induced ventilation has been suggested.

When does an atrium enhance natural ventilation?

This paper investigates passive displacement flows in a simple, two-compartment building that comprises a single storey connected to an atrium. Heat gains in the storey and solar gains in the atrium create a stack pressure which drives a ventilating flow. A model is developed to determine the steady flow rate and thermal stratification for a range of heat gains, storey and atrium heights, and ventilation opening areas.

Pollutant dispersion simulated with tracer gas in a naturally ventilated test house.

The New Zealand Building Code has kept with tradition in allowing residential building ventilationdesigns based entirely on openable window areas. Working against this tradition, however, is a trend inNew Zealand towards more airtight construction and declining reliance on open windows. Contributingto this trend are changing patterns of occupancy with fewer people at home during the working week,along with developing concerns for personal security.

On the impact of the urban environment on the potential of natural ventilation.

Knowledge and estimation of the wind speed and air flow characteristics, in a city, is of vitalimportance for passive cooling applications and especially in the design of naturallyventilated buildings. This study is referred to the analysis of the wind characteristics in urbancanyons as a function of the free stream wind. The impact on the airflow rate calculation isdiscussed for an urban canyon. The goal of this study is to get a better insight of the impact ofthe urban environment on the ventilation effectiveness.

Natural ventilation activated by induction.

This article describes a ventilation system, developed within the framework of aEuropean project supported by the JOULE III programme (NAVAIR project). Theconcept used - natural ventilation assisted by air induction combines the advantages ofnatural ventilation and the performances of mechanical ventilation.

Integration of indoor and outdoor airflow study for natural ventilation design using CFD.

Natural ventilation is one of the most fundamental techniques to reduce energy usage inbuildings. However, due to complicated site plans and building layouts, it is difficult todesign optimal layouts for the enhancement of ventilation without knowledge about the flowpatterns. The employment of computational fluid dynamic (CFD) tools in the design processcan give predictive feedback to the designers, allowing them to optimize airflow around thesite to decide on building placement, orientation, and interior space layout.

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