7
Bypass and frost protection
The kair heat recovery unit iECO 4 is delivered
as standard with a bypass valve. This valve is
completely integrated in the unit and ensures that,
if required, the fresh outside air ows directly to
the air supply system instead of through the heat
exchanger. In this case there is no heat transfer
between the warmer discharge air from the home
and the colder intake air that is drawn into the
home. The fresh outside air is blown directly into
the home. This is denitely an advantage in the
summer, when the outside air is often cooler than
the air within the home.
The unit includes, as standard, frost protection.
This protection ensures that the unit does not
freeze during the winter. The frost protection
consists of a unique frost valve integrated at
the top of the unit. The frost protection is fully
automatic.
In the heat recovery unit the fresh (colder) out-
side air is par tly heated by the air discharged
from the home. The exchange of heat takes place
when both air ows are led through the heat
exchanger. The discharged air may be cooled to a
temperature very near freezing by the cold air
entering the unit from outside. In this case, the
unit will regularly open the frost valve and take
in warm air from the home. This warm air is
mixed with the cold air that is taken in from
outside. The temperature of the intake air is,
therefore, higher and the discharge air in the
heat exchanger will also be safely above freezing.
The unit will thus not freeze.
4
In a balanced ventilation system the volume of
air coming from outside equals the amount of air
discharged from the home. The outside air suc-
tsorfehtnehwretsafsnrut,erofereht,nafnoit
protection is triggered. Thus, the volume of air
coming from outside remains the same as the
amount of air discharged from the home. The
total volume of air intake increases proportionally
with the volume of air taken in from the home by
the frost valve. Opening the frost valve is not
sucient when the outside temperature is even
lower. The intake fan will turn more slowly and,
after some time, the discharge ventilator will
turn faster. The air, therefore, remains above free-
ehtfoecnalabmiyraropmetanistlusersihT.gniz
ventilation (the volume of air coming from outs-
ide is no longer equal to the amount of air
edistuoehtnehW.
)emohehtmorfdegrahcsid
temperature increases, the unit automatically
resets the fans to the initial values. The ventilation
is thus once again balanced.
The electronic components are important parts
of the unit. The electronic components control
the operation of the unit when you set the mode
switch. The motor is set to the speed that ensures
the desired ventilation. The electronic components
consist of a basic printed circuit board and an
optional radio frequency module. This can be
used to extend the ventilation unit with radio
frequency operation.
The user should not touch the electronic
.evilebyamstnenopmocesehT.stnenopmoc
Bypass4.1
Frost protection4.2
Electronic components4.3
