[AIVC, Air infiltration and ventilation glossary, 1992]:the pressure differential across a building caused by the differences in the density of the air due to an indoor-outdoor temperature difference.(see neutral pressure level).[EN 16798-7:2017, 3.12]:pressure difference caused by the difference in density between indoor and outdoor air due to an indoor/outdoor temperature difference.[SOURCE: EN 12792:2003, definition 339]