AIVC - Air Infiltration and Ventilation Centre

Search form


You are here



Statistical prediction model of the outdoor / indoor air pollutant transfer

Efficient control of ventilation systems needs information on indoor air pollutant concentration. But most of the time, the pollutant concentration is not measured. However, outdoor air pollution forecast models are becoming operational and a relation between outdoor and indoor pollutant concentration may be used to predict pollutant concentration peaks and to infer recommendations to reduce its value . A prediction model of the outdoor/indoor air pollutant transfer, based on experimental data, was obtained using multiple linear regression.

Assessment of the effect of air filtration and ventilation on reduction of exposure to submicrometer particles indoors.

The provision of a healthy and satisfactorily clean indoor environment requires that consideration be given to a range of issues, such as the type of indoor environment, indoor and outdoor sources, indoor activity and others. The selection of relevant measures to achieve the required indoor air quality (IAQ) depends on knowledge and understanding of the mechanisms and parameters affecting the concentration levels indoors.

Connection between ultra-fine aerosols indoors and outdoors in an office environment.

Measurement campaign was conducted in a controlled office environment during January 1999 to get indoor/outdoor ratio for particles less than 0.5 micrometers in diameter. Aerosol concentrations for diameters between 7-500 nanometers were measured simultaneously indoors and outdoors with two DMPS systems. Other continuously measured quantities included temperature, ventilation rate, relative humidity, air pressure and four inorganic gases (S02, NO, NOx and 03). The measured room was practically airtight and had a mechanical ventilation system.

Effect of recirculation on the local mean age of air.

When it is required to predict the local mean age of air, the calculations are often carried out assuming that there is no recirculation that is that all of the supply air is fresh. However, local mean age values will be greater than in the fresh air case when some of the exhaust air is recirculated. This paper examines and discusses the effect of recirculation and shows that, for many systems the increase in local mean age due to recirculation can be calculated by means of an elementary analysis that leads to a simple algebraic expression.

Natural smoke filling in atrium with liquid pool fires up to 1.6 MW.

Experimental studies on natural smoke filling in an atrium induced by a liquid pool fire up to 1.6 MW were carried out. The new full-scale burning facility, the PolyU/USTC Atrium constructed at Hefei in China, was used. Five sets of hot smoke tests with diesel pool fires of 2 x 2 m placed on the floor were carried out. All openings were closed, except leaving a small vertical vent of 0.2 m high for supplying fresh air. Transient variations on the mass of the burning fuel, the vertical temperature distributions and the smoke layer interface heights were measured.

CFD based airflow modelling to investigate the effectiveness of control methods intended to prevent the transmission of airborne organisms.

The airborne transmission of disease is a constant threat and while diseases such as Tuberculosis were considered all but extinct in the western world, the resurgence of it demonstrates that the spread of these diseases has to be taken very seriously. This paper describes the method of application of Computational Fluid Dynamics (CFD), more appropriately called Airflow Modelling for the Building Services Industry, to the airflow and heat transfer in a Hospital Isolation Room Application.