DESIGN AND OPERATING PRINCIPLE
The unit operation is as follows:
Warm extract air from the room flows into the unit and is cleaned in
the extract filters. Then the air is moved through the heat exchanger
and is exhausted outside through the air ducts with the extract fan.
Cold fresh air from outside flows into the unit, where it is cleaned with
the supply filters. Then the air flows through the heat exchanger and
is moved to the room with the supply fan. Supply air is heated in the
heat exchanger by transferring the heat energy of warm and humid
extract air to the cold fresh air. The air flows are fully separated while
flowing through the heat exchanger. Heat recovery minimizes heat
losses, which reduces the cost of space heating in the cold season.
The unit is a frame structure made of rigidly fixed steel panels. The
panels are made of painted steel sheets and a galvanized steel sheets
with a layer of mineral wool between for heat- and sound-insulation.
UNIT DESIGN
UNIT OPERATING PRINCIPLE
Supply filter
Extract filter
Control unit
Temperature sensor
Electric reheater
Heat exchanger
Bypass air damper actuator
Supply fan
Supply filter
Supply air damper
Extract fan
Electric preheater
Exhaust air damper
Extract air
Exhaust air
Intake air
Extract air
Supply air
The service door enables access for maintenance and service
operations.
The power cables and grounding conductors must be routed
through the cable glands to the terminal block located on the top
casing panel. The wiring diagram for wiring of the air handling unit
is shown on the inner side of the terminal box lid. The unit design
enables installation of a bypass duct with a bypass damper to route
the intake air stream without contacting the heat exchanger. The
unit has three automatic heat exchanger freeze protection modes,
depending on the unit model.
Units without heater
: the supply fan turns off in case of a freezing
danger*.
Units with a reheater and no preheater:
the bypass system is
activated in case of a freezing danger*.
Units with a preheater:
the preheating is turned on in case of a
freezing danger*.
* danger of freezing appears when the exhaust air temperature
downstream of the heat exchanger is lower than +5 °C and intake
air temperature upstream of the heat exchanger is lower than -3 °C.
After increase of these temperatures the unit reverts to the
previous operation mode.
The supply and extract air temperature difference during heat
recovery may lead to condensate formation in the units with a
polystyrene heat exchanger. The condensate is collected in the drain
pan and is removed outside to the exhaust air duct through the drain
hose. No condensate is generated in the units with an enthalpy heat
exchanger as the air moisture is transferred from one air stream to
the other via the membrane.
The unit has options for connection of a humidity sensor, CO
2
sensor
or VOC (air quality) sensor for automatic keeping of set humidity
level, CO
2
or VOC concentration in the room.
SETUP MODE
button
(for units with
S21/S22/S25
automation)
civic ec lB(e)(2) 300/500(-e)
8
www.blaubergventilatoren.de
