That study carried out particle transport measurements for full-scale timber frame structure similar to a wooden floor. The penetration is highly dependent on pressure difference and not on holes in the surface boards of the structure. The results showed that surface contacts of mineral wool with other building elements may have an important role in penetration.
Penetration of inert particles with a size range from 0.6 to 4 µm and spores of Penicillium and Cladosporium was studied through a full scale timber structure. Pressure difference and air leakage over the structure were varied. Measurements at moderate pr
Laboratory trials were performed in order to search for the variety of the production ofmicrobial volatile organic compounds (MVOC), which could be used as indicators for hiddenmould damage. Concerning the MVOC production the experiments showed a dependency onthe building materials used as substrate and on the genus or species. It could be proved thatthe production of certain MVOC is not consistent at all times. On the whole low emissionrates in terms of g h-1 of the MVOC were found.
Accurate and informative sampling methods are very important in the evaluation of fungalexposure in indoor air quality (IAQ) investigations. We have investigated the relationshipbetween indoor culturable airborne and dust-borne fungi and compared the performance ofculturable and non-culturable air samplersReuter Centrifugal Air Sampler (RCS) and ZefonAi-O-CellTM (AOC).
In buildings growing conditions for mould fungi can occur and cause fungus infestation. Thepossible danger for the occupants of dwellings lies in the production and spreading ofpathogens (disease causing agents). Therefore, consequent measures have to be taken to avoidhealth dangers that result from mould fungi in buildings. A strategy has to be set up thatfocuses on the growth conditions for mould fungi and also considers the complex transientprocesses of building physics.
Microbial growth has been known as one of the major problems related to IAQ inresidential and commercial buildings. International and local standards define theupper limits of indoor relative humidity in order to avoid moisture related problems.However, setting limits on indoor relative humidity does not guarantee a mould-freeenvironment.
Thirty classrooms in 10 schools in Shanghai, China, were investigated in winter. Dust wascollected by vacuum cleaning, analysed for ergosterol, muramic acid, and 3-hydroxy fattyacids (LPS) by tandem mass spectrometry (GC-MSMS). Airborne microoganisms weresampled on Nucleopore filters (CAMNEA). The compound 1-octen-3-ol was found in higherconcentrations in indoor than in outdoor air. Total indoor bacteria were positively correlatedto both LPS and muramic acid in settled dust. Indoor and outdoor air contained many viablespecies.
We measured the temperature, relative air humidity (RH), carbon dioxide (CO2), ozone (O3),nitrogen dioxide (NO2), and formaldehyde levels in 30 classrooms in 10 schools in Shanghai.The pupils received a questionnaire; 1414 participated (99%). The temperature was 13-21C,and RH was 36-82%. The 1000 ppm CO2 level was exceeded in 45% of the classrooms.Indoor formaldehyde was 3-20 g/m3. The concentration of O3 was low, both indoors (
Increasing emphasis on energy-efficiency has many jurisdictions enacting stricter energy codes. Yet, these same green building codes typically do not adequately address ventilation when a building envelope is designed to both minimize infiltration/exfiltration and maximize thermal efficiency. Our company investigated an apartment complex in Southern California, U.S.A. that was designed 25% more thermally efficient than required by State Code. Within months of occupancy, the first complaints of biological growth at windows and closets occurred.
Mold in dwellings is a persisting complaint in moderate climates. Nine parameters intervene in it: (1) climate, (2) inside temperature, (3) vapor release, (4) ventilation, (5) lay out, (6) envelope thermal performance, (7) sorption inside, (8) presence of preferential condensation surfaces and (9) type of finish. Exterior climate acts as boundary condition while inside temperature, vapor release and ventilation belong to the living habits. The five others are design and construction related.