EN
7. OPERATING MODE
7.1 Winter operating mode
The return air from the room, with a higher thermal
load than the fresh air, crosses the plate heat exchanger,
where it gives up part of its thermal load and cools
down before being exhausted. The fresh air, with
a lower thermal load than the return one from the
room, crosses the plate heat exchanger in the opposite
direction and heats up before the introduction into
the room. The modulation of the airflow rate, through
variation of the rotation speed of the EC fans, will allow
a precise control of the supply air temperature. During
winter operation, in particular working conditions with
low external temperatures, the heat exchanger could
be subject to the formation of surface frost with consequent loss of efficiency.
To prevent this from happening, the unit provides for the controlled management of an automatic defrosting cycle, obtained by
means of a self-regulated electric battery in PWM mode, installed on the room air intake. The system increases the temperature
of the exhaust air thus avoiding the risk of frost on the heat exchanger. The system is controlled by a specific temperature probe
positioned on the air outlet and guarantees a considerable reduction of the power absorbed by the unit, compared to the traditional
systems on the market.
7.2 Summer operating mode
The return air from the room, with a lower thermal load
than the fresh air, crosses the plate heat exchanger,
where it takes part of its thermal load and heats up
before being exhausted. The fresh air, with a higher
thermal load than the room air, crosses the plate heat
exchanger in the opposite direction and cools down
before the introduction into the room.
The modulation of the airflow rate, by varying the
rotation speed of the EC fans, will allow a precise control
of the supply air temperature.
7.3 Free-Cooling operating mode
When the outdoor air temperature is lower than the
temperature of the room to be air-conditioned and if the
latter requires cooling, the unit operates in Free-Cooling
mode by opening the By-Pass damper positioned on
the plate heat exchanger and thus allowing the entry of
outdoor air without heat recovery.
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