2. Function
The decentralised ventilation system of the type AIRUNIT „GEMINI“ is a device for domestic ventilation with
and without heat recovery. The ventilators in the decentralized ventilation unit type GEMINI run simultaneously in opposite
directions of rotation (push-pull operation), i.e. one ventilator conveys outdoor air into the installation room of the ventilation
unit, while the other ventilator conveys exhaust air from the installation room into the open air. There is no mixing of the air
flows at any time.
A decentralized ventilation system of the type GEMINI thus consists of two individual ventilation units in one housing,
which are equipped with a central control system.The air ducts of both units are separated and sealed from each other. It is
therefore not possible to mix supply and exhaust air flows.
In the ventilation stack, the thermal energy of the exhaust air volume flow is loaded into the heat exchanger. The absorbed
thermal energy is transferred back to the supply air in the ventilation stack. In this phase, a regenerative heat transfer takes
place, which heats up the outside air and returns it to the installation room as supply air. In this way a heat recovery of up to
98% is achieved.The cycle time for changing the direction of rotation of the axial ventilators is approx. 70 seconds.
Via the integrated humidity sensor or alternatively via a switch, the unit can be set to pure exhaust air operation, resulting in
an exhaust air volume flow of 40m³/h.
2.1 Planning information
Before installing AIRUNIT Gemini ventilation units, a ventilation concept should be drawn up consisting of
to which the number of ventilation units, their installation location and the position / number of the associated
AIRUNIT regulations.
With AIRUNIT GEMINI ventilation units the following ventilation variants are available:
• Ventilation of a room/apartment unit with one ventilation unit, alternating supply/exhaust air operation with
heat recovery, cross ventilation without heat recovery and exhaust air operation without heat recovery.
AIRUNIT GEMINI ventilation units are suitable for ventilating apartments or comparable usage units.This is made
possible by the fans in the ventilation unit, which work in push-pull mode and ensure a balanced volume flow of supply
and exhaust air.
The AIRUNIT GEMINI units must not be used in interior, windowless exhaust air rooms such as kitchens, bathrooms and
toilets, as it is not permitted to connect the units to a shaft or pipe. Here the use of an exhaust air fan in accordance with
DIN 18017 T.3 is recommended.The unit cannot be installed in cellars with light shafts either, as recirculation of the
exhaust air cannot be excluded. To prevent recirculation when the units are mounted on the facade, a minimum distance
of 1.0 m should be maintained between individual units.We recommend not using the unit if the building is exposed to
wind (average wind speed > 5 m/s). In order to avoid drafts caused by the operation of the ventilation units If you want to
avoid this, the air diffusers on the room side should not be arranged directly above seating areas or similar. Ensure that the
room-side air diffuser is not impaired by furniture or curtains.
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