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TF7128_A_NOT_INST_DXR230_EXC_MB
Aereco S.A.
2.
DESCRIPTION
2.1. GENERAL INFORMATION
The DX System is a range of smart heat recovery ventilation systems that continually supply pollen-free and dust-free preheated fresh air to living areas,
ensuring a comfortable feel-good climate.
The DXR is a heat recovery unit with demand-controlled airflows for horizontal installation (in the false ceiling) in the apartment or in the house, from 2 to
5 main rooms, and from 1 to 5 technical rooms (kitchen, bathroom, others wet rooms). The apartment is limited to 2 floors (1 ground floor and 1 floor
maximum), and has a maximum surface of 210 m². This HRV system can also be used in offices, hostels, etc., if the required airflow is in accordance
with the one offered by the system.
General working of the DX System, Excellence Version
The DX System is comprised of a heat recovery unit (DXR Unit
1
) connected to exhaust and supply ductworks. The counter-flow heat exchanger,
integrated into the main unit, ensures the recovery and transfer of most of the energy from the exhaust air to the supply air, thus limiting the energy
required to heat the fresh air.
Airflows are automatically controlled according to the needs of each dwelling’s room (room-by-room DCV): Outdoor filtered air is supplied
3
in the
bedrooms and in the living room. Stale air is extracted
5
from the kitchen, bathroom and WC. On the supply side, the different sensors
4
adjust the
airflow room-by-room based on the CO
2
level or based on the presence detection. On the exhaust side, the BXC units adjust automatically the airflow,
according to parameters read by various sensors: humidity (used in the kitchen, in the bathroom and in WC), presence (can be used in WC). Versions
with switch, presence, remote, CO
2
or VOC sensors can also be used for exhaust units.
At all times, total supply airflows and total exhaust airflows are measured by the heat recovery unit. At all times, these airflows are balanced on the
exhaust side an exhaust controlled compensation valve
7
can modulate an additionnal over-exhaust airflow. This valve can be located in the bathroom
or in the kitchen. On the supply side, the hub can modulate an additional over-supply airflow by over opening the pipes'dampers. Exhaust compensation
valves is linked to dedicated compensation exhaust unit
6
. The pipes of the hub are linked to dedicated compensation supply unit
3
The use of an
exhaust compensation valve is also a solution to increase the airflows. This scenario is used in order to get a very efficient over-ventilation mode, also
called free-cooling mode.
To reach the required supply airflows in each main room (bedrooms or living room), dedicated dampers located in the DX Hub
2
modulate room by
room supply airflows according to the information sent by each electronic sensors placed in the main rooms. For example, when the main rooms are
occupied, the presence or CO
2
sensors that are located in these rooms send the information to the system to adapt the airflow according to the demand.
To reach the required exhaust airflows in each technical room (kitchen, bathroom, WC, ...), dampers located in the exhaust units modulate room by room
extract airflows according to the passive or active sensor placed within each exhaust unit.
Supply airflows and exhaust airflows are measured by the use of accurate pressure sensors placed in the heat recovery unit. This allows to calculate with a
high accuracy supply and exhaust airflows, without influence of clogging filters or ductwork pressure drop. It ensures the highest efficiency for the system.
So that, energy savings are at their maximum.
Specific working
of the DXR Excellence version
The Excellence version corresponds to the best
HRV solution in terms of indoor air quality and
energy savings. In this version, the DX System
adapts airflows room-by-room based on
specific needs, while balancing supply and
exhaust. A distribution box (DX Hub
2
),
connected to CO
2
or presence sensors
4
located in all the different main rooms, adjusts
supply airflows through dampers. The exhaust
airflows are controlled by humidity sensors or
presence detectors or other activators in the
exhaust units.
Presence detection
The presence sensors located in the main
rooms (at least 1 sensor in the main rooms)
send the information to the system (presence
detected or not) with a timer that depends on
the period through luminosity measurement
(day or night). This timer keeps the detection
at the maximum level during 20 or 45 minutes
after the last detection, to optimize the quality
of detection. Timer day = 20 min ; Timer
night = 45 min. When there is detection, the
local supply airflow is increased to ensure the
best air quality. If there is no detection, the
local supply airflow is reduced to optimize
energy savings.
CO
2
detection
Based on the level of CO
2
in the room, a
consequence of people occupancy, CO
2
sensors are a really good indicators to
modulate the supply airflows and allow
reliable measurement of the concentrations of
CO
2
in a zone. The analysis principle consists
in measuring the absorption of infrared light
in order to determine the concentration in a
room. This method gives a very accurate
response and is not affected by any other
pollution (humidity, dust, etc.).
