Ventilation performance of large buildings: Prediction using pressurisation measurements

Abstract

This paper provides a model which uses whole-building leakage measurements to predict the ventilation performance of buildings and illustrates its use by applying it to a large, industrial building. Air leakage measurements with the building 'as found' and then with its loading doors sealed showed a 14% reduction at an inside/outside pressure differential of 25 Pa. Using these leakage characteristics, the model predicted ventilation rates which corresponded well with measured values. Meteorological data at the site for the heating season were combined with the ventilation characteristics of the building (given by the model) to predict the ventilation performance of the building over that period. The results indicated that the building 'as-found' would have, on average, an air change rate of 0.5 h-1 which reduces by 24%, i.e. to 0.38 h-1, when the loading doors are made airtight. Calculations also indicate that such a retrofit measure would reduce by 14% the total energy required for space heating over that period.