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The Building Components Technology Department of ICITE, the Central Institute forIndustrialization and Technology in Building of the Italian National Research Council hasstarted an experimental research on natural controlled ventilation devices.Today the air quality of an indoor environment may have several effects on our health, due tothe presence of polluting and extremely noxious agents in the places we most frequently use.That is the reason why ICITE has undertaken to develop a research and an experimentationstudy aimed at establishing a device for the controlled natural ventilation of

The fractional collection efficiency (FCE) tests of a commercially available two-stageelectrostatic precipitator (ESP) have been performed for six flow rates. The tests covered theparticle size range from 0.018-1.2micrometer using two types of test aerosols, NaCl andenvironmental tobacco smoke (ETS). Measurements were performed by means of twoScanning Mobility Particle Sizers (SMPS) and the Aerodynamic Particle Sizer (APS).

As a result of the recent resurgence in tuberculosis (TB), there has been renewed interest inengineering controls to reduce the spread of TB and other airborne infectious diseases in highrisk settings. This paper presents the results of experimental studies evaluating the efficacy ofultraviolet germicidal irradiation (UVGI) of room air in reducing the concentration of viableairborne bacteria. Bacterial particles (Bacillus subtilis spores and Mycobacteriumparafortuitum) were continuously generated in a 90m room.

Emissions from dust collected in air filters have been investigated using in situ and chambermeasurements. Two air filters (class F6 and F8/9) were exposed to outdoor air for a period ofsix months, after which measurements were carried out during continuous and intermittentoperation. Air samples were taken upstream and downstream of the filters and analysed forseveral substances, including VOCS, formaldehyde, microbial VOCS (MVOC), vital microorganisms,ergosterol and endotoxin.

The role of indoor plants as a source of microorganisms was studied in six office rooms.Concentrations of microorganisms (both fungi and actinomycetes) were determined fromindoor air and settled dust before the plants were placed in the office rooms and afterwardswith the plants in the rooms.

Avariety of gaseous pollutants in indoor air now are becoming an object to control. Thus, westudied a removal technique using TiO2 photocatalyst under 365 nm or 254 nm UV-lightirradiation for toluene, benzene, formaldehyde and acetaldehyde as examples of hazardousvolatile organic compounds (VOCS), in order to get detailed analytical data for productsderived from these contaminants. Although these compounds were effectively destructed, notonly CO2 but also high concentration of toxic compounds, such as aldehydes were formed inthe case of under 365 nm UV-light irradiation.

As part of an ongoing investigation on service life of air filtration material, a new type of airfiltration material (multi-layered polymer) was compared with a widely used material todetermine growth or survival of micro-organisms after normal dust loading. Blinding wasperformed by the manufacturer supplying the materials as anonymous A and B. Microorganismswere extracted after 2, 4, 6, and 8 weeks by washing (shake out) and plating thesolution onto agar media, incubated and differentiated. Vital fluorescence microscopy wasalso performed. The results showed a significant difference (P

Air recirculation in the new office and laboratory building of the Norwegian Institute for AirResearch was discovered and characterised from a leaking sulphur hexafluoride cylinderstored in the garage. The garage/staging area was located at the far end of the right wing ofthe three-storey building, and was used for loading/unloading of equipment and for storage ofequipment and compressed gas cylinders. Sulphur hexafluoride tracer was detected in thecorridor on the ground floor right wing leading to the central reception area.

Models are presented for describing the performance of room air cleaners in removing pollutants from indoor air, particularly the levels of removal that can be achieved in practice. Controlled levels of pollutant were generated in a room environmental chamber, and the performance of a commercial room air cleaner was assessed according to the models. The room environmental chamber was operated in static (sealed) or dynamic (ventilated) modes.

Snow has already been used effectively as a cold energy resource in some heavy snowfall areasin Japan. As the surface of snow is covered with cold melting water when snow is used as a coldenergy resource, we can expect gas absorption on the surface. By this mechanism of the gasabsorption, some airborne contaminants such as dust or harmful gases can be removed by themelting snow surface.