Klimatförändringarnas inverkan på mögel- och rötangrepp
(2011) In TVBK VBK920 20102Civil Engineering (M.Sc.Eng.)
Division of Structural Engineering
- Abstract
- The purpose of this Master’s Thesis is to investigate how the risk of onset of mould and decay
will change due to a changing climate. The research encompasses the time period 1960-2099
in open fields near the cities Göteborg, Lund, Stockholm and Östersund for the emission
scenarios A1B, A2 and B1. The risk of onset of mould and decay is studied on wood in
outdoor climate as well as the risk of onset of mould for an exterior wall.
In order to calculate the risk of onset of mould a dose-response model was used. For the risk
of decay another dose-response model was used. Both models depend on the daily mean
values of the temperature and relative humidity. The decay model also depends on the daily
precipitation. The outdoor... (More) - The purpose of this Master’s Thesis is to investigate how the risk of onset of mould and decay
will change due to a changing climate. The research encompasses the time period 1960-2099
in open fields near the cities Göteborg, Lund, Stockholm and Östersund for the emission
scenarios A1B, A2 and B1. The risk of onset of mould and decay is studied on wood in
outdoor climate as well as the risk of onset of mould for an exterior wall.
In order to calculate the risk of onset of mould a dose-response model was used. For the risk
of decay another dose-response model was used. Both models depend on the daily mean
values of the temperature and relative humidity. The decay model also depends on the daily
precipitation. The outdoor climate was modelled by the global climate model ECHAM5 and
the results were downscaled using the regional climate model RCA3 to take the Nordic
topology into account. This was done for all three scenarios by Rossby Centre at the Swedish
Meteorological and Hydrological Institute. The specific humidity, radiation and wind from the
climate models had to be transformed so they could be used in the mould and decay models
and the computer program WUFI.
The computer program WUFI was used together with the modelled outdoor climate to model
the climate in the exterior wall. The exterior wall was assumed to be a wood stud wall with a
wooden facade. The climate in the exterior wall was modelled for three ten-year time periods
and this was done for all the cities and scenarios. The observation point was located on the
boundary between the air gap and the outer insulation.
The values for both the relative mould and decay doses for wood in outdoor climate were
higher for the modelled climate than compared to the observed one during the years of 1961-
1990. Since there was a major difference in the relative humidity between the modelled
climate and the observed one (but no difference for the temperature or precipitation) it was
concluded that the humidity was the main reason for high values of relative mould and decay
doses. For Östersund the relative mould dose was much higher for the modelled climate than
the observed one. Since Östersund had considerably more days with high relative humidity,
above 97 %, whilst the temperature was above 0.1°C it was concluded that this was the
reason behind the high relative mould values for Östersund. The results for both the mould
and the decay onset indicate that the values for both mould and decay start to rise after the
year 2040. This was concluded to happen because it was around this year the temperature
started to increase continuously whilst the relative humidity didn’t have any significant
changes.
The relative mould dose for the modelled climate in the exterior wall is much lower than for
the modelled outdoor climate. The difference was concluded to depend on the increased
temperature due to the heat flow from the indoor climate. The temperature change lead to a
lower relative humidity, but the moisture transport in the wall meant that this change was not
as large as the temperature increase first suggests. Between the two last ten-year periods the
relative mould dose increases significantly. As mentioned before the temperature rises during
these years are the main reason for the increase in relative mould dose. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/3358495
- author
- Jeppsson, Hans LU and Lindahl, Karl LU
- supervisor
- organization
- course
- VBK920 20102
- year
- 2011
- type
- H3 - Professional qualifications (4 Years - )
- subject
- keywords
- climate change, mould, decay, exterior wall
- publication/series
- TVBK
- report number
- TVBK - 5193
- ISSN
- 0349-4969
- language
- Swedish
- id
- 3358495
- date added to LUP
- 2013-01-10 13:08:58
- date last changed
- 2013-01-10 13:08:58
@misc{3358495, abstract = {{The purpose of this Master’s Thesis is to investigate how the risk of onset of mould and decay will change due to a changing climate. The research encompasses the time period 1960-2099 in open fields near the cities Göteborg, Lund, Stockholm and Östersund for the emission scenarios A1B, A2 and B1. The risk of onset of mould and decay is studied on wood in outdoor climate as well as the risk of onset of mould for an exterior wall. In order to calculate the risk of onset of mould a dose-response model was used. For the risk of decay another dose-response model was used. Both models depend on the daily mean values of the temperature and relative humidity. The decay model also depends on the daily precipitation. The outdoor climate was modelled by the global climate model ECHAM5 and the results were downscaled using the regional climate model RCA3 to take the Nordic topology into account. This was done for all three scenarios by Rossby Centre at the Swedish Meteorological and Hydrological Institute. The specific humidity, radiation and wind from the climate models had to be transformed so they could be used in the mould and decay models and the computer program WUFI. The computer program WUFI was used together with the modelled outdoor climate to model the climate in the exterior wall. The exterior wall was assumed to be a wood stud wall with a wooden facade. The climate in the exterior wall was modelled for three ten-year time periods and this was done for all the cities and scenarios. The observation point was located on the boundary between the air gap and the outer insulation. The values for both the relative mould and decay doses for wood in outdoor climate were higher for the modelled climate than compared to the observed one during the years of 1961- 1990. Since there was a major difference in the relative humidity between the modelled climate and the observed one (but no difference for the temperature or precipitation) it was concluded that the humidity was the main reason for high values of relative mould and decay doses. For Östersund the relative mould dose was much higher for the modelled climate than the observed one. Since Östersund had considerably more days with high relative humidity, above 97 %, whilst the temperature was above 0.1°C it was concluded that this was the reason behind the high relative mould values for Östersund. The results for both the mould and the decay onset indicate that the values for both mould and decay start to rise after the year 2040. This was concluded to happen because it was around this year the temperature started to increase continuously whilst the relative humidity didn’t have any significant changes. The relative mould dose for the modelled climate in the exterior wall is much lower than for the modelled outdoor climate. The difference was concluded to depend on the increased temperature due to the heat flow from the indoor climate. The temperature change lead to a lower relative humidity, but the moisture transport in the wall meant that this change was not as large as the temperature increase first suggests. Between the two last ten-year periods the relative mould dose increases significantly. As mentioned before the temperature rises during these years are the main reason for the increase in relative mould dose.}}, author = {{Jeppsson, Hans and Lindahl, Karl}}, issn = {{0349-4969}}, language = {{swe}}, note = {{Student Paper}}, series = {{TVBK}}, title = {{Klimatförändringarnas inverkan på mögel- och rötangrepp}}, year = {{2011}}, }