Influence of Local Weather Conditions on Ventilation of a Pitched Wooden Roof

Abstract

This paper investigates the influence of temperature and wind conditions on ventilation of the air cavity beneath the roofing in a full-scale pitched wooden roof construction. The potential for condensation in the air cavity is studied. The relevant roof construction is equipped with 81 thermocouples and four air velocity measurement devices. A weather station at the site records outdoor temperature and wind conditions. Five periods between 2016 and 2018 are investigated. The findings show distinct periods of below-ambient temperature and positive condensation potential in the ventilated air cavity of the roof. A relation between low wind speed and positive condensation potential is shown. Difference in size of periods with below-ambient temperature and periods with positive condensation potential implies that the materials in the roof regulate the humidity in the air cavity. Large negative peaks in the condensation potential indicate dry-out of the construction.