Airtightness of Buildings – Considerations regarding the Zero-Flow Pressure and the Weighted Line of Organic Correlation

This paper discusses two particular points of the buildings airtightness measurement method (ISO 9972) in relation with the calculation of the combined standard uncertainty: (1) the zero-flow pressure difference and (2) the weighted line of organic correlation.

Airtightness of buildings - Calculation of combined standard uncertainty

The paper presents a calculation method for the combined standard uncertainty associated with the buildings airtightness measurement done in accordance with the ISO standard 9972:2006 (or EN 13829).

The method consists in an application of the law of propagation of uncertainty (JCGM 100:2008) combined with a linear regression (y = a x + b). It goes from the measured values to the air leakage rate and the air change rate.