Mapping of surface moisture and thermal transmittance of historic building walls with the use of thermography and the heat flow meter method

Historic buildings are a unique source of knowledge and experiences different from present buildings and often house historical artifacts. An expected change in the future climate is anticipated to change the historical buildings’ indoor environment, dangerously affecting the microclimate around the historical artifacts housed in these buildings. A case study of the historical building Snekkenes at Borgarsyssel Museum, Sarpsborg, was performed in order to map the walls’ surface moisture and thermal transmittance. These maps were also generated in order to determine areas at higher risks of mold growth and the linear thermal bridge coefficient. The surface conditions behind the historical artifacts, which covered the wall, are also presented in this thesis. Infrared thermography and heat flow meters were used in order to determine the thermal transmittance of the walls. The thermal images, from the infrared thermographic survey, were also used in order to generate maps of larger sections of the walls for the thermal transmittance and relative humidity on the surface. For the larger wall sections, Pix4D was used in order to make maps of the temperature, thermal transmittance and relative humidity over the surfaces. This program was also used in order to generate orthophotos from visual images taken of Snekkenes. The thermal images taken of areas behind the historical artifacts were processed in MATLAB as they were not generated into maps. The results showed that there was little to no difference between the thermal transmittance calculated from the thermal images and the heat flow meter at the location where the heat flow meter was mounded in Werenskiold-hall. However, in other areas indoor, the resulting thermal transmittance maps were greatly influenced by the indoor convection. Outdoor it was found that the thermal transmittance maps were affected by changes in the reflected temperature