EN
The article is concerned with the stability of the tuning of historic organs which have their air system supplied, in terms of the positioning of the instrument itself, from an external environment. It addresses the question of the temperature changes in sacred buildings, which are an essential magnitude for the analysis. The analysis also touches on the mode of the construction used for the air system, since this construction has a fundamental influence on the constant change of pressure and air temperature in the air system. We have verified the entire analysis in situ under real conditions, also by means of an experiment regarding the analysis of tuning. The positioning of the air system, sucking in air which differs in temperature from the air where the instrument itself is positioned, does not have any destructive effect on the tuning of the historic organs and hence does not damage this tuning in any way.