Kritiskt fukttillstånd för mögelpåväxt på byggnadsmaterial

Critical moisture level for mould growth on building materials. Mould can grow on building materials in 75-100% relative humidity (RH) at room temperature. How sensitive materials are to mould growth varies. One way to describe this sensitivity is the critical moisture level, RHcrit, the lowest RH at which mould can grow on a material. The critical moisture level for different material groups was proposed based on the current research situation in 2005, in the report ” Microbiological growth on building materials – critical moisture levels. State of the art” (SP Rapport 2005: 11). Based on new research results, these values are no longer valid. This report provides a general overview of the conditions for mould growth on building materials, focusing on the critical moisture level and the new research results. The main conclusion is that RHcrit is a product-specific property. It is impossible to estimate RHcrit for a product based on that it belongs to a group of materials, such as plaster or wood-based boards. Instead, RHcrit must be determined by laboratory tests for each product. The report also discusses how the results of a laboratory test can be used to prevent mould growth in buildings with known RF and temperature and the benefits of using RHcrit instead of traditional mould resistance tests

Kritiskt fukttillstånd för mögelpåväxt på byggnadsmaterial

Critical moisture level for mould growth on building materials. Mould can grow on building materials in 75-100% relative humidity (RH) at room temperature. How sensitive materials are to mould growth varies. One way to describe this sensitivity is the critical moisture level, RHcrit, the lowest RH at which mould can grow on a material. The critical moisture level for different material groups was proposed based on the current research situation in 2005, in the report ” Microbiological growth on building materials – critical moisture levels. State of the art” (SP Rapport 2005: 11). Based on new research results, these values are no longer valid. This report provides a general overview of the conditions for mould growth on building materials, focusing on the critical moisture level and the new research results. The main conclusion is that RHcrit is a product-specific property. It is impossible to estimate RHcrit for a product based on that it belongs to a group of materials, such as plaster or wood-based boards. Instead, RHcrit must be determined by laboratory tests for each product. The report also discusses how the results of a laboratory test can be used to prevent mould growth in buildings with known RF and temperature and the benefits of using RHcrit instead of traditional mould resistance tests

Threshold values for mould growth: Critical moisture level of 21 different building materials

The susceptibility for mould growth varies among different building materials. One way to describe the susceptibility is the lowest RH at which mould can grow on a specific material, the critical moisture level (RHcrit). Determining RHcrit for materials provide the basis for material choice in designs where moisture and temperature conditions are known. In this study, RHcrit of 21different products were determined according to SIS-TS 41:2014/SPMet 4927. This test method is developed based on the results of a variety of laboratory studies and validated by field studies. Test specimens were inoculated with a suspension containing spores from six different mould fungi and were then incubated in moisture chambers at four levels of RH at 22 °C. After 12 weeks specimens were analysed for mould growth. RHcrit was determined based on the lowest RH at which mould grew on the specimens. RHcrit varied among different products, even between product belonging to a similar group of material, for example, calcium silicate boards or gypsum boards. The results show, and confirm, previous findings that it is not possible to estimate RHcrit for a specific product based on material group. Instead, each product must be tested

Experiences from a field test using ICN for live video streaming

Information Centric Networking (ICN) aims to evolve the Internet infrastructure from a host-centric to a data-centric paradigm. In particular, it improves performance and resource efficiency in events with large crowds where many users in a local area want to generate and watch media content related to that event. In this paper, we present the design of a live video streaming system built on the NetInf ICN architecture and how the architecture was adapted to support live streaming of media content. To evaluate the feasibility and performance of the system, extensive field trials were carried out over several days during a major sports event. We show that our system streams videos successfully with low delay and communication overhead compared with existing Internet streaming services, supporting several thousands of simultaneous users