The penetration of cold outdoor air into industrial buildings is a severe problem in countries having a cold, arctic or subarctic climate. The cold air, penetrating into the building mainly through the open doorways, causes discomfort to the workers, disturbs the functioning of the ventilation system and increases the energy and maintenance costs of the building. What even worse, the industrial process could be disturbed and even stopped, which could lead to high production and financial losses.

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