The renowned chair of the RWTH Aachen confirms the high efficiency of the smartengine technology

Expert opinion based on building simulation analysis

Demand-oriented mechanical ventilation in combination with lighting control can make a considerable contribution to energy and economical savings in non-residential buildings without compromise of thermal comfort. To fulfill that potential, wtec GmbH develops the product smartengine. By means of dynamic building simulation, the effects of applying smartengine in two modern office buildings are analyzed separately: four cellular offices with equal use conditions but different orientations on the one hand and an open space office comprising four large office areas which are spread over a whole floor of another building on the other hand. Each office has its own user profiles.

The simulations are performed with the AixLib Modelica library based on a low-order multi-zone model, where building geometries and physics are represented by thermal resistances and capacities. The model where also solar shading is taken into account is enriched with parameters of the mechanical ventilation system, the heating and cooling power in rooms and the intensities of internal gains like people, machines and lighting. Time profiles of lighting power and airflow rates of the ventilation system differ between the reference case with a constant volume flow during operation hours and the smartengine-variant with dynamic profiles according to occupancy rates. The annual energy demands of the two variants are calculated with the same hourly weather data for each building. Furthermore, the results are extended to primary energy demand and economical savings.