Itho Daalderop HRU 400, Installation & Use Manual

Page: 15 / 49

15
2.9. Schemes
The HRU 400 has a standard 3-position control where the
ventilation flow rate can be adjusted with the Itho Daalderop
service app. In addition, the ventilation unit has an automatic RH
control that functions continuously in the background when the
unit is in the Auto position.
2.9.1. Heat recovery
Before the polluted air is removed to the outside, it is filtered and
passed through the heat exchanger. The fresh outside air is also
filtered and passed through the heat exchanger before it is brought
into the house. In the heat exchanger, the two air currents are
routed past each other (i.e. they are not mixed with each other). As a
result, the energy of the exhaust air is transferred to the fresh supply
air, so that this energy is not lost. In winter, the colder outside air is
thus heated. In summer, the relatively colder indoor air is transferred
to the warmer supply air so that it becomes less warm.
2.9.2. Automatic ventilation based on RH
measurement
The ventilation unit is equipped with an internal RH sensor.
The sensor measures the increase in humidity and
automatically adjusts the ventilation accordingly.
In addition, it is also possible to connect a wireless RH sensor to
the ventilation unit. This sensor can be mounted in any room but
preferably in a room where a lot of moisture is produced, such as
a bathroom.
2.9.3. Summer bypass scheme
The purpose of the summer bypass control is to ventilate the
house with less, or completely without, heat transfer.
The Itho Daalderop heat recovery unit HRU 400 is supplied as
standard with a bypass valve integrated in the unit. This valve
works automatically. The bypass valve ensures that the
extracted indoor air is guided around the exchanger. The
supply air still passes through the air filter and the exchanger.
This automatic regulation will come into effect mainly at night, in
summer. The outside air is then usually cooler than the warm inside
air. The bypass control ensures that the house remains cooler for
longer.
2.9.4. Vorstregeling
The purpose of the frost control is to prevent the heat exchanger
from freezing and to prevent ventilation.
If the temperature of the supply air in the heat exchanger is too far
below freezing point, the unit will regularly open the frost flap at the
top of the unit and draw in warm room air. This warm room air is
mixed with the cold outside air drawn in. At the same time, the
supply fan starts to turn harder (the fan is speeded up so that the
amount of fresh outside air remains the same). Because the fresh
cold outside air is preheated, the warm extracted air from the
house does not have to heat the cold freezing air as much.
Should the outside temperature drop even further, the supply
fan will turn softer (the fan will be turned down to a minimum).
If the outside temperature rises, the above measures are carried
out in reverse order until the danger of frost has passed. The
resident 'always' determines the discharge air quantity.
2.9.5. Automatic ventilation based on CO2
measurement (optional)
A
CO2 sensor
can be connected to the ventilation unit which
communicates wirelessly with the unit.
The sensor can be mounted in any room (except the bathroom),
but preferably in living rooms and/or bedrooms.
The controllable sensor measures the
CO2 concentration
in the room. It
translates the measured value into a ventilation wish and
communicates it wirelessly to the ventilation unit to which the sensor
is connected. As the
CO2 concentration
in the room increases as the
room is used more intensively, ventilation will gradually increase.
Note
Despite the heat exchange, the balanced ventilation system
should not be regarded as a heating or cooling system. It
prevents the loss of heat through ventilation.
Tip
It is possible to place several wireless sensors and controls in
the house, up to a maximum of 20 pieces.
ä Attention
!
Control based on wireless sensors (
CO2
and/or RH) only works
if the ventilation unit is in Auto/Auto night mode.