In-field investigation and comparison of two devices for drying masonry walls

The in-field investigation and comparison of a wet masonry wall drying process applying two drying devices is presented in this paper. Walls subjected to drying were a part of a basement of a historic building that was subjected to renovation works and which is located in the City of Łowicz (Poland). Both devices implement the thermo-injection method which is used for drying walls. The first device was the currently use device (CUD) and second one was a novel prototype with optimized control of drying parameters. The dedicated data acquisition system was developed to in-situ monitor parameters of the drying process. Air parameters like temperature and relative humidity in several points in the basement, temperature and moisture content at various locations in investigated walls as well as electrical parameters for both devices were measured and registered. The specific energy consumption during the drying process defined as energy consumption divided by the mean volumetric moisture content (MC) drop between the initial and final state in the wall and by the length of the dried wall section after 120 h of drying process was estimated to be 16.58 and 10.44 kWh/moisture content vol.%/m for CUD and new prototype, respectively. In this time the wall moisture content decreased by an average of 2.13 vol.% and 3.22 vol.% for the CUD and prototype, respectively. Moreover, temperature of wall surface in the drying zone was increased to approximately 35–40 °C and 40–55 °C for the CUD and prototype, respectively. The investigation showed that the new prototype is much more efficient than the CUD.