Demand Controlled Ventilation Systems

The purpose of the Bachelor’s thesis was to compare different approaches to demand-controlled ventilation (DCV) systems which can be applied to school buildings, and to find the most suitable system to satisfy the need for better indoor air quality in classrooms while providing highest potential energy savings. Literary sources were studied to establish the base approaches to automatically control ventilation systems on the basis of room occupation levels, as well as the usage of these tools in existing products available in the market. Major focus was given to CO2 control systems since, in theory, they should directly tackle the problems with indoor air quality in classrooms in most cases. The thesis also includes sample calculations of airflow balance for CO2 based ventilation control systems. The result showed that DCV systems are an important tool to achieve good indoor air quality and that, in most cases, CO2-based control systems will provide the best result. In addition, most modern ventilation systems available tend to compile multiple methods in one product, even including specific measurement methods