During the last 20 years, the humidity sensitive ventilation system evolved to products increasingly simplified thus standardised. At Aereco, there were 5 generations of extract units, each modification of product was due to a change in the acceptation criteria. In many countries, systems with variable airflows are accepted and recognised ; regulations moved. In other countries, the orthodoxy of the constant airflow of an air change per hour remains in force for simplifying reasons or by ignorance of the real interest. Laboratories and design offices had also to adapt themselves to new technologies, it was the case when the thermostatic radiator control or the programmable thermostats appeared on the market. The period of the all-ornothing is definitively over. 1.500.000 dwellings equipped with humidity sensitive ventilation systems in the world is the evidence that the system is working well and that it is well accepted. The yearly energy saving is 1.500 giga Wh. The control of the energy consumption is now an important issue, even the politics are involved : less consumption means less pollution, so few risk of super oil tanker passing by our coasts. The saving of our technology is close to a super oil tanker each year. Ventilation plays a small part in the overall necessary energy saving however it is real role.