Modern houses are more and more energy efficient and airtight, which is why a ventilation system must be built to ensure air exchange. In the case of a heat recovery ventilation system, supply and exhaust pipes are built into the rooms. In general, living quarters, bedrooms and other rooms all have exhaust pipes. Such a system ensures balanced air circulation in the premises, which ensures a high-quality indoor climate. In the case of a heat recovery system, up to 95% of the heat of the extracted air is used to heat the fresh air coming in, free of charge. Compared to exhaust ventilation only, where the heat of the extracted air is not used, there can be up to a 40% saving in heating costs. When a heat recovery ventilation system is combined with a demand driven innovative Airobot ventilation unit, costs are kept to a minimum. In addition to energy savings, such a system can significantly improve the well-being and the quality of the indoor climate, as the ventilation unit constantly monitors the humidity and carbon dioxide (CO2) content in the air and reduces them if necessary.