Ventilation is a critical part of a building's technical systems and solutions, which provide the building with its specific conditions. Today's houses are designed to be tight and energy-efficient so that properly engineered ventilation, adjustment and in-use ventilation will have a significant impact on the indoor climate conditions, healthy functioning of the house, and above all, energy-efficient maintenance of the building.

The thesis examined the control options of ventilation, and sought to create an optimization tool to facilitate the selection of necessary controlling options for demand-controlled ventilation (DCV). The thesis was divided into two parts, the first one dealing with the basic aspects of ventilation, and the second one being mainly a statement of work focusing on examining the effects of ventilation control with the help of a computer modelling. The project was commissioned by A Niemi Engineering Oy, a South-Karelian HVAC-engineering and consultancy office.

In order to achieve the objectives of the work, a realistic exemplary object case, for which the entire ventilation system was built, was needed as a basis for study and analysis. It was essential for the ventilation system to have a sufficient amount of technology to implement the demand-controlled ventilation into practice. Different load and operating situations were used to study the behavior of the system with varying changes to adjustment and control, all within the limits of the guidelines and regulations defined by the existing building regulations.

As a result, the work achieved to provide more understanding on the demand-controlled ventilation control and also the optimization tool made to assist ventilation planning. The current version of the optimization tool provides an opportunity for further development according to planning needs and potential variable limits.