New article was published in 6th International Building Physics Conference about “Moisture supply Set Point for avoidance of moisture damage in Swedish multifamily houses!”. The authors are Abdul Hamid A., Wallentén P., and Johansson D.
From 1950 until 1975 approximately 1.3 million apartments were built in Sweden. Now, a considerable part of these are in need of renovation. This paper is part of an evaluation of a new DCV system developed especially for the renovation of these houses. The DCV automatically regulates the air change rate for each dwelling based on measurements of the indoor air. One of the measured parameters is the moisture supply. Simply put, the ventilation rate increases when the measured moisture supply exceeds the set point based on a PI-controller. In this paper, simulations have been carried out to determine an appropriate set point for the moisture supply for avoidance of moisture damage on biological building materials. A worst case scenario has been considered and the general maximal set point is recommended to be 3 g/m3.
To fulfill the demands by the directives of the European Union 2020  and 2050 , Sweden must retrofit its current building stock in order to achieve a lower energy output. The multifamily buildings in need of renovation consist of more than a million dwellings. These were built from 1950 to 1975, and are in need of renovation or retrofitting mostly due to the building materials and building services having reached, or even passed, the end of their lifespan. With new regulations in Sweden, renovated buildings must fulfill the same requirements as new buildings which means that they usually have to be retrofitted to a higher standard regarding moisture, energy and ventilation. In order to renovate effectively and properly, new solutions must be developed to solve common issues that arise during and after the renovation process. These solutions must also be properly evaluated for optimization of energy efficiency and a healthy indoor environment. One such solution is a new ventilation system that has been designed especially for alleviating common issues that arise during the renovation process. The new system is a demand controlled ventilation (DCV) system for multifamily houses, which automatically regulates the air change rate (ACR)
for each dwelling. This paper aims to evaluate the set point for the moisture supply of this new DCV.