Ventilation filters are classified according to the results from standard laboratory tests. These tests, however, produce information which may be insufficient for estimating the true filter performance. The properties of a ventilation filter in the ambient air conditions may be quite different compared to filter behavior in the standard test. The disagreement may be especially strong in the case of electrostatically charged filters. The loss of electrostatic removal mechanism can lead to a significant decrease in the efficiency.

There has been lack of fact based knowledge for design and operation of supply air jilter for general ventilation. An Invent multi-component project was started in 1994 to tackle this problem area. The paper describes the basic performances of air filters and requirements to be included in the Design Guide Handbook, managed by Invent, Finland.

Nosocomial transmission of Mycobacterium tuberculosis (MTb) is a recognized risk to health care workers in the U.S. In 1994, the U.S. Centers for Disease Control and Prevention (CDC) published Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Facilities, 1994. (1) The Guidelines included recommendations for design and operation of Mfb isolation rooms.

Indoor climate affects occupational safety and comfort. When indoor climate conditions are on an optimum level, the number of accidents decrease while productivity and quality of the work increase. A new design guide for good indoor climate in commercial  kitchens is a result of the project "Research and Development Project of Commercial Kitchen Ventilation" started in 1996. Research pointed out that indoor climate conditions in commercial kitchens are not on an acceptable level

Quantitative and qualitative gas analysis is widely needed in present modern industrialized societies. The reasons for this need range from purely economical interests, to meeting the requirements of environmental and occupational health legislation. Examples of these applications include process effluent monitoring, emission monitoring, workplace safety monitoring, clinical blood gas monitoring, toxic gas monitoring in fires, chemical warfare agent detection and ambient air monitoring.

The presence of airborne contaminants in the production environment can create problems to products, production equipment and personnel. The improvement of the production environment is a complex task and therefore, unprofitable control measures are common. PIMEX and similar equipment (1-6) combines video picture of the work and simultaneously measured data from the sensors detecting e.g. airborne contaminants. Link between problem calling conditions and work can be analysed with the aid of video picture in which graphical presentation of data is superimposed.