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Neue Untersuchungsergebnisse zum Phänomen "Schwarze Wohnungen"

Recent results of investigating the phenomenon of "Black Magic Dust"
 
: Moriske, H.-J.; Salthammer, T.; Wensing, M.; Klar, A.; Ebert, P.; Meinlschmidt, P.; Pardemann, J.; Riemann, A.; Schwampe, W.

Gefahrstoffe, Reinhaltung der Luft 61 (2001), No.9, pp.387-394
ISSN: 0039-0771
ISSN: 0949-8036
German
Journal Article
Fraunhofer WKI ()

Abstract
The effect of suddenly appearing large-surface black deposits in living spaces (phenomenon of "Black Magic Dust") which has been increasingly observed in recent years has been examined systematically in an extensive program of measurements. Eight housings concerned were selected. In addition to chemical analysis already applied in the past, particular emphasis was laid on the recording and characterization of airborne dust and on thermographic measurements. For investigations, it is important to know if the phenomenon is still "active" at the time of measurement or if it is already "inactive". As claimed in the past, the visible black surfaces are essentially caused by (fine) dust particles. The presence of semivolatile organic compounds (SVOC) on wall surface supports particle absorption. In this context, a distinction must be made between an "adhesive film effect" and an "airborne effect" (fogging). However, no final answer to the question if these effects are alwaiys required "as a first step" for creating these phenomena could be obtained. Time resolved thermography provided proof for colder wall areas, thermal bridges and especially the type for air flow being the decisive factors starting this phenomenon. Besides, the intensity of black precipitations also depends on individual living behaviour. No relation between the phenomenon and outside air influences and VOC emissions could be discerned, the same applies to the simultaneous occurrence with microbial indoor contaminations.

: http://publica.fraunhofer.de/documents/N-6951.html