Airaksinen M.
Bibliographic info:
Report A7 - Helsinki University of Technology - Dissertation for th degree of Doctor of Science in technology, pp 1-66, 37 Fig., 10 Tab., 110 Ref.

The objective of that study was to find out the important properties of ground covers, the optimal air change rates for the controlling of moisture conditions in an outdoor air-ventilated crawl space in a cold climate, and to estimate the acceptability of current moisture conditions in respect of material durability. In addition, factors affecting the transport indoors of possible pollutants from crawl spaces were studied.
The moisture conditions were calculated with a dynamic simulation model, which was validated against measured data.
Results from field measurements showed a correlation between microbes in the crawl space and indoors.
Laboratory measurements showed that the penetration was highly dependent on pressure difference and not dependent on holes in the surface boards of the structure.
To avoid the penetration of fungal spores it is necessary to balance the building.
The results indicate that mechanical exhaust ventilation causing an under-pressure in the building may cause health risks if some contamination exists in the building envelope.