Surface condensation risk is a fact that has to be dealt with when buildings are airtight. Airtight buildings with lower ventilation rates are the result of applying energy saving policies and criteria. Surface condensation risk depends greatly on the ventilation rates, as well as on another factors such as generation of water vapour, climate, envelope components and U value, etc. In order to assess the risk of condensation all these factors need to be taken into account. Commonly used condensation assessment methods only study climate conditions in January, but in a relatively dry climate such as the Spanish one, other times of the year could present a higher risk of condensation due to the higher values of humidity.
This paper presents the research on the assessment of the surface condensation risk due to the higher outdoor humidity in two Spanish climates. The results of the surface condensation risk assessment are presented for four types of dwellings, according to the number of bedrooms and bathrooms and for two distinct Spanish climatic zones, both having an average high relative humidity. The study analyses the influence of the outdoor climate conditions into the risk and proposes a broader assessment during the whole year.