We spend over 80% of our time in the indoor, no matter in the home or the office. If the carbon dioxide around 1500ppm disturbs our wellbeing and efficiency, above 5000ppm, we are starting to become hazardous and 10000ppm is life threatening As the energy crisis made us aware of the cost of burning fuel we started to dense walls, windows and doors. In order to save energy and feel better, in the world of HVAC this development has been going on for at least 20 years. And that is also our importance market. IOT with home or office automation, it has made the invisible visible and connected with the cloud, to make sure the air is safe and fresh.