SA-V-4L

Functional description

Decentralised supply and extract air units ventilate the room and cover the cooling and heating load in accordance with the technical data. An EC centrifugal fan takes in the outdoor air which then flows through the motorised shut-off damper and the outdoor air filter. The outdoor air then flows through the cross flow heat recovery unit, which can be switched off in energy efficient operating situations. 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 passes through the extract air filter, then flows through the heat recovery unit, the extract air fan and the motorised shut-off damper before it is discharged to the outside as exhaust air. If the indoor air quality is sufficient, the FSL-CONTROL III control system switches to energy-efficient secondary air mode by closing the outdoor air dampers. The control system compares the room air quality setpoint value to the actual value measured by the CO2 sensor and switches automatically between outdoor air and 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. Near the external wall, 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 after entering the room. As a result, in cooling mode, the supply air spreads out like displacement flow over the entire floor area. Near heat sources such as people or equipment, a lift current is formed by natural convection, so that the air is exchanged primarily in these areas.