A methodology to assess the IAQ performances of ventilation systems in residential buildings.

Until now, there is no widely accepted way to express any index for this purpose and takinginto account the large variety of possible pollutants. Things can be simptied if the aim k tocompare different systems and strategies rather than to give an absolute value of quality.For the study of a pollutant source, the main important point for comparison is the pattern ofits production, whatever this pollutant is. The detailed data for each inhabitant is the curve ofthe number of hours above a pollutant level concentration.

A hygrothermal model for predicting house dust mite response to environmental conditions in dwellings.

House-dust mite antigens are a major contributor to allergic sensitisation. Since temperatureand humidity are crucial to house-dust mite physiology, there is considerable interest inreducing mite populations by controlling the indoor environment.

Thermal comfort and indoor air quality in forty-three flights.

This paper reports the results of thermal comfort and indoor air quality studies in forty-three flights with a duration of more than one hour. The measurements were performed continuously during the whole flight (from the departure gate to the arrival gate) and the parameters monitored were temperature, relative humidity and carbon dioxide concentration. The results were then compared with the ASHRAE Standards for the thermal and indoor air quality.

Vegetation influences on the human thermal comfort in outdoor spaces.

The purpose of this work is to evaluate the thermal comfort of human beings in outdoor spaces, taking into account the microclimatic modifications produced by vegetation. The parameters needed to formulate a comfort index are of differing orders of magnitude, so the same conditions could be seen as comfortable outdoors and yet be unacceptable indoors. One of the most influential landscape elements in the degree of comfort is vegetation. The main effects of vegetation are on solar radiation and wind.

Impact of teleworking on indoor climate at home.

The greater availability of information and telecommunication technologies and the trend towards flexible working practices allow the home and the workplace to coexist. Many studies mainly emphasize economic and social consequences of teleworking. However, there is no assessment of energy and indoor climate impact of teleworking at home. Furthermore a professional activity is usually not envisaged at home, and home is not built according to the same building design process as offices. Consequently, teleworking at home raises new questions about the evolution of dwellings.

Ventilation efficiency in dwelling cells: contribution to the validation of a zonal model.

Since reduction of ventilation rates in dwellings for economical reasons, it has been necessary to study whether this reduction had not been done to the detriment of indoor air quality. Several means of investigating were developed: experimental tests are indispensable but usually expensive that is why numerous research centres choose to model the thermoconvective fields in rooms.

The influence of nocturnal ventilation reduction on indoor air quality.

The energy saving practice of stopping ventilation systems at night may reduce the daytimeair quality. Sorption phenomena where pollutants absorbed at night are reemitted during theday and the general slower removal of pollutants at the reduced average ventilation rates willcontribute to the deterioration of air quality at intermittent running systems. The purpose ofthe study was to investigate the impact on construction product emission during the day fromreduced ventilation rates at night. Experiments were performed in three small-scale chambersof Climpaq type with dilution systems.

Numerical prediction of mixed turbulent airflow within a cavity using various turbulence models.

The overall objective of the present work is to evaluate the performance of three turbulence models, with a view to predicting characteristics of airflow within an anisothermic cavity. The standard K-c. model, the Renormalisation Group model (RNG) and the Reynolds stress model (RSM) are used in conjunction with the Fluent code. The accuracy and the relative performance of the three models are evaluated by comparing their numerical results with experimentally obtained data. This comparison is made for the constant flow rate of a twodimensional turbulent mixed convective airflow.

Greenhouse natural ventilation by buoyancy forces.

Convective transfers mainly determine the energy and mass balances which regulate the micro-climate inside a greenhouse. Air flow and temperature patterns induced by natural ventilation through greenhouse roof openings are only considered here. Flow visualizations were performed on a half scale test cell simulating the absorption of solar radiation at the floor surface of a single-span greenhouse. Temperature and air flow patterns were observed in a steady regime i) with a single sided roof vent and ii) with two symmetrical one.

A novel concept of facade for daylighting and natural cooling.

The role of metallic surfaces is not only to save energy in winter and in summer by separating the inside and the outside. New and inexpensive ways of collecting solar energy for internal heating, new ways of ventilating, heating and cooling through the fabric elements are described. Two very significant prospects are : radiative cooling by metallic surfaces and enhancement of indirect daylighting by optimised ceilings. The subject of the European CURES program is to promote these new technologies by simulating and testing them.

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