Analysis and optimisation of dynamic facility ventilation in recirculation aquacultural systems

Facility ventilation is one of the main energy consumers in a recirculation aquacultural system (RAS).In this work, operating points have been optimised in order to maintain an acceptable facility climate on the one hand but an energy input as low as possible on the other hand. The energy savings have been quantified by evaluation of energy input into the ventilation stream at various flow rates. Moreover, additional measurements have been undertaken in order to understand the correlation between air humidity in the facility, ventilation rate, humidity production of the RAS and ambient climate. The main findings are that dynamic facility ventilation offers a significant potential for energy savings up to 85% compared to a static operation at design flow rates according to DIN EN 13779. Air humidity–as a major constraint–is predominantly affected by ambient climate conditions. Based on the main findings, a first approach for a dynamic ventilation strategy (i.e. for automation) has been made.