Where the introduction explained briefly the benefits that could be drawn from an efficient ventilation control system, this paper aims at giving a general survey of the needs and the difficulties encountered when applied to routine ventilation. It also focuses the attention on elements that already have to be considered at the early stage of the project. These elements should enable the designer to decide whether a ventilation control system would be suitable or not. Particular aspects which are not necessarily difficulties but should not be overlooked, are also put forward. The paper goes successively through the control principles that may be applied to classical ventilation systems in single tube tunnels and in mixed ventilation systems. It touches on difficulties with multiple fan systems and ventilation systems with more than one fresh air supply unit. The control loops, whether they would be automatically or manually operated, may use as actuating variable measured quantities that are either concentration values of one or more contaminants or traffic characteristics. A more optimal solution would be a combination of both. Particular attention is drawn to all aspects concerning the quality of the input data and their information content. The choice of certain control variables is also discussed. It should be understood that the paper does not address the particular aspects of fire and smoke control which is a topic on its own. For the covering abstract see ITRD E135448.
Abstract