How the air quality of crawl space influences the indoor air quality is investigated using a simulation program “Fresh 2010”, air leakage network models, and the measurement results on the mould concentrations in cr...How the air quality of crawl space influences the indoor air quality is investigated using a simulation program “Fresh 2010”, air leakage network models, and the measurement results on the mould concentrations in crawl spaces of detached houses. The annual changes of indoor mould concentrations were calculated using building models (a common wooden post-and-beam structure, improved wooden post-and-beam structure, wooden stud structure). In every structure, the concentrations in the case of exhaust ventilation system are higher than those of exhaust and supply ventilation system. The results show that it is necessary to control the air quality of crawl spaces and the infiltration from crawl spaces in order to keep indoor air quality good.展开更多
The indoor mould concentration depends not only on the outdoor mould source but also on the indoor mould source. The mould source is not only on the interior surface but also in the concealed spaces: a crawl space, a ...The indoor mould concentration depends not only on the outdoor mould source but also on the indoor mould source. The mould source is not only on the interior surface but also in the concealed spaces: a crawl space, a beam space, a wall cavity etc. Most detached houses in Japan have crawl spaces under the first floor. The humidity is high from spring to autumn in crawl spaces. Therefore the concentration of mould spore is very high in most crawl spaces. Prefabricated bathrooms called “bath-units” are installed in most Japanese houses. The authors showed in the previous studies that there are infiltration routes between bath-units and walls that the routes may lead chemical compounds from crawl space to indoor space. In this study, the influence of mould infiltration from crawl space upon indoor mould concentration is investigated using a test house which consists of a lavatory and a bathroom. The structure of the house is wooden post-and-beam. The house is airtight and insulated according to the latest building code for save energy. The mould concentrations were measured in the crawl space and the indoor spaces continuously using a mould multi-sampling system with a pump, valves and impingers. Before the measurements, the indoor mould concentration was made low using an air cleaner. The air flow rates were measured using tracer gases. After the exhaust fan was switched on, the mould concentration increased. The number of infiltrated mould was calculated using air flow rates and mould concentrations. The results showed that mould infiltration ratio may be one of the important indicators of indoor air quality.展开更多
文摘How the air quality of crawl space influences the indoor air quality is investigated using a simulation program “Fresh 2010”, air leakage network models, and the measurement results on the mould concentrations in crawl spaces of detached houses. The annual changes of indoor mould concentrations were calculated using building models (a common wooden post-and-beam structure, improved wooden post-and-beam structure, wooden stud structure). In every structure, the concentrations in the case of exhaust ventilation system are higher than those of exhaust and supply ventilation system. The results show that it is necessary to control the air quality of crawl spaces and the infiltration from crawl spaces in order to keep indoor air quality good.
文摘The indoor mould concentration depends not only on the outdoor mould source but also on the indoor mould source. The mould source is not only on the interior surface but also in the concealed spaces: a crawl space, a beam space, a wall cavity etc. Most detached houses in Japan have crawl spaces under the first floor. The humidity is high from spring to autumn in crawl spaces. Therefore the concentration of mould spore is very high in most crawl spaces. Prefabricated bathrooms called “bath-units” are installed in most Japanese houses. The authors showed in the previous studies that there are infiltration routes between bath-units and walls that the routes may lead chemical compounds from crawl space to indoor space. In this study, the influence of mould infiltration from crawl space upon indoor mould concentration is investigated using a test house which consists of a lavatory and a bathroom. The structure of the house is wooden post-and-beam. The house is airtight and insulated according to the latest building code for save energy. The mould concentrations were measured in the crawl space and the indoor spaces continuously using a mould multi-sampling system with a pump, valves and impingers. Before the measurements, the indoor mould concentration was made low using an air cleaner. The air flow rates were measured using tracer gases. After the exhaust fan was switched on, the mould concentration increased. The number of infiltrated mould was calculated using air flow rates and mould concentrations. The results showed that mould infiltration ratio may be one of the important indicators of indoor air quality.
