Characterization of a hygro-regulated Wall Base Ventilation System for Treatment of Rising Damp in Historical Buildings

Abstract

The treatment of rising damp in the walls of historic buildings is very complex, due to the thickness andheterogeneity of the walls. The techniques traditionally used for dealing with this problem (such as watertightbarriers, injection of hydrofuge products, etc.) have sometimes proved ineffective, and that is why it is necessaryto find a new approach.In recent years, the Building Physics Laboratory at the Faculty of Engineering, University of Porto has beenconducting experimental research on the effectiveness of the wall base ventilation system, using natural ormechanical higro-regulate systems to reduce the level of the damp area. This experimental research and thesimulations that were performed, clearly show that wall base ventilation is a system with potential.This paper presents the characterization of the hygro-regulated systems operation based on experimentalstudies developed in laboratory, which allowed the influence of the velocity of the air, condensation risk and thepossibility of salt crystallization. This will also present the results of measurements conducted in churches in theNorth of Portugal in which these systems were implemented, with the purpose of validating its operation andestablishing criteria for programming the ventilator.