X-CUBE SCHOOLAIR-V-HE 

Functional description

Decentralised supply and extract air units ventilate the room and cover the cooling and heating load in accordance with the technical data. The outside air is drawn in by an EC centrifugal fan and flows through the motorised shut-off damper and the outdoor air filter. The outdoor air then flows through the crosscounterflow heat recovery unit, which can be switched off in energy-efficient operating situations and to protect the device. Before the supply air flows into the room like displacement air, it is heated or cooled in the heat exchanger if required (optional for 4-pipe units). The extract air first flows through the extract air filter, before it is discharged to the outside as exhaust air, by passing the heat recovery unit, the extract air fan and the motorised shut-off damper. If the indoor air quality is sufficient, the FSL CONTROL III controlsystem switches to energy-efficient secondary air mode by closing the outdoor air dampers. The control system comparesthe room air quality setpoints to the actual values measured bythe CO2sensor and switches automatically between outdoor airand secondary air operation. In case of a power failure, the outdoor air and exhaust air dampers are closed to ensure fire protection, frost protection and to avoid draughts. This is ensured by a capacitor in each actuator. Close to the façade, the supply air is discharged into the room with a medium velocity between 0.5 and 0.8 m/s. Due to the induction effect, the supply air velocity is rapidly reduced so that, in cooling mode, the supply air spreads across the entire floor area as a displacement flow. Near heat sources such as people or equipment, a buoyancy flow is formed by natural convection, so that the air is exchanged primarily in these areas.