Our commitment to improve both air quality and energy savings in existing dwellings involves scopemeasurements campaigns. Constraints linked to the use of measurements material in these conditions, the keeping of their reliability all project long and their costs prompted industry to develop special devices for this kind of application. It is the case of this high accuracy manometer required for the wide demonstration project called HR-VENT (Nangis- France). This monitoring carried out during almost 2 years aims in particular at characterizing the running of a hybrid ventilation system in place of an existing passive stack ventilation system.All in all, more than 160 manometers are installed to measure pressure differences near extract units and gas appliances. Small pressure differences, such as those measured in passive stack ventilation and the required accuracy lead Aereco to design a powerful device with a reasonable cost.