37º IAHS World Congress on Housing: - Universidad de Cantabria

XXXVII <strong>IAHS</strong><strong>World</strong> <strong>Congress</strong> on HousingOctober 26 – 29, 2010, Santander, SpainCODE: 949HUMIVENT – NEW SYSTEM FOR THE TREATMENT OFRISING DAMPVasco Peixoto de Freitas and Ana Sofia GuimarãesBuilding Physics LaboratoryDepartment of of Civil EngineeringUniversity of Porto, Faculty of Engineeringe-mail: vpfreita@fe.up.pt; anasofia@fe.up.ptKey words: rising damp, treatment, HUMIVENTAbstractThe rising damp is one of the most important factors in the degradation of the masonry andstone walls in historic buildings. The level reached by the dampness and the degradation thatit produces, especially by the phenomenon of the dissolution and crystallization of salts,depends on multiple factors [1]: the hygric properties of the materials, the permeability tosteam of the layers, the inner and exterior climatic conditions, etc.Traditional methods of dealing with this problem [2] are not effective in the resolution of allthe problems, which is the reason for proposing a new technique based on ventilation of thewalls bases using the device “HUMIVENT”. It is a system that uses air as a transportmechanism of the moisture, which controls the level reached by the damp front and requireschannels being placed at the base of the walls, below ground level. The circulation of air inthe interior is controlled by the device.The sizing of the treatment system is based on knowledge of the characteristics of the wall, ofthe geometry of the ventilation system and of the building being dealt with. The system isessentially composed by a ventilator (variable speed) activated by a set of temperature andrelative humidity probes that transmit information to the ventilator depending thehigrothermal conditions of the incoming and the outgoing air.This paper describes the validation of the idea and the description of the system.37º <strong>IAHS</strong> <strong>World</strong> <strong>Congress</strong> On Housing Science 320