The heating and cooling loads due to air infiltration may be estimated by a mathematical model that requires knowledge of the leakage characteristics of each component of the envelope. To extend the modelisation to the pitched roofs common in Portugal, characteristics of roofs were determined by a differential pressure method.
Experimental determination of empirical flow coefficients for air infiltration through pitched roofs
2nd International PLEA Conference, Crete, 28 June-1 July 1983. Passive and Low Energy Architecture, edited by Simos Yannas. Oxford:Pergamon