7
DESIGN AND OPERATING PRINCIPLE
UNIT OPERATION LOGIC
Heat Recovery mode: warm stale extract air from the room flows into the unit, where it is filtered by the extract filters, then air flows
through the heat exchanger and is exhausted outside by the extract fan. Cold fresh air from the outside flows into the unit, where it is
cleaned by the supply filters. Then the air flows through the heat exchangers and is directed to the room with the supply fan. Heat energy
of warm extract air is transferred to clean intake fresh air from the outside and warms it up. 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.
Summer Cooling mode: the bypass damper is opened, the intake air that is supplied to the premises bypasses the heat exchanger and
its temperature doesn’t change.
The units have three frost protection modes (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):
— gradual reduction of the supply fan speed
— with the bypass
— with the electric preheater (if the unit is equipped with a preheater)
Mode selection and settings are described in the control system user’s manual.
Extract air
Exhaust air
Intake air
Supply air
UNIT DESIGN
The units are available in left-hand and right-hand design. Choosing the right arrangement can improve the ease of installation, shorten
the length of the ducts and reduce the number of air duct bends.
Extract air
Exhaust air
Intake air
Supply air
Extract air
Exhaust air
Intake air
Supply air
Right-handed modification
Left-handed modification
