Zehnder Rittling ComfoAir 70 User manual

Decorative Radiators Comfortable indoor ventilation Heating and cooling ceiling systems Clean air solutions
Operating and installation instructions for user and installer
Zehnder ComfoAir 70

EN
Legal regulations
All rights reserved.
This manual has been compiled with the utmost care. Nevertheless, the publisher accepts no liability for damage caused
by missing or incorrect details in this manual. We reserve the right at any time and without previous notification to change
the content of these instructions in part or as a whole.
The information contained in these documents is the property of Zehnder Group. Publication, as a whole or in parts,
requires the written approval of Zehnder Group. In-house duplication, designated for the evaluation of the product or for
proper use, is permitted and not subject to approval.
Zehnder manufacturer's warranty
The current warranty terms can be obtained in paper form using the normal distribution channels.
Trademarks
All trademarks are recognized, even if they are not separately labelled. A missing label does not mean that an article or
sign is free of trademark rights.
© 2017 Zehnder Group

EN 3
Contents
0Preface .................................................................................................................................... 5
Validity...................................................................................................................................... 5
Target group and standard operation ...................................................................................... 5
Qualification of target group..................................................................................................... 5
0.2.1.1 Users........................................................................................................................................ 5
0.2.1.2 Qualified personnel.................................................................................................................. 5
Standard operation of the unit.................................................................................................. 5
1Introduction and safety ......................................................................................................... 5
Proper use................................................................................................................................ 5
ComfoAir 70 ventilation unit..................................................................................................... 5
Control panels.......................................................................................................................... 5
Safety....................................................................................................................................... 6
Safety regulations .................................................................................................................... 6
Installation conditions............................................................................................................... 6
Symbols used........................................................................................................................... 6
Warranty and liability................................................................................................................ 6
Warranty provisions ................................................................................................................. 6
Liability ..................................................................................................................................... 7
2Instructions for the user and qualified personnel.............................................................. 7
Product description .................................................................................................................. 7
Type label................................................................................................................................. 8
Frost protection ........................................................................................................................ 8
2.1.2.1 Frost protection mode.............................................................................................................. 9
Joint operation with fireplaces.................................................................................................. 9
Functionality of the internal and external control panel ........................................................... 9
Operating functions and signalling from the control panel..................................................... 10
Automatic operating mode.....................................................................................................12
2.3.1.1 Functional principle of HUMIDITY sensor.............................................................................. 13
2.3.1.2 Functional principle of CO2/ VOC sensor.............................................................................. 13
Maintenance by the user........................................................................................................ 13
Replacing the unit filters......................................................................................................... 14
Resetting the filter runtime..................................................................................................... 15
What should I do in case of a malfunction?........................................................................... 15
Disposal.................................................................................................................................. 16
3Instructions for the qualified personnel............................................................................ 16
Installation requirements........................................................................................................ 16
Transport and packaging ....................................................................................................... 16
Checking the scope of delivery.............................................................................................. 16
Installation.............................................................................................................................. 16
General installation instructions.............................................................................................16
Installation preparations......................................................................................................... 17
Connecting the ventilation tubes (only for adjoining room connection)................................. 17
Installing the ventilation unit................................................................................................... 19
Electrical connections ............................................................................................................ 22
3.2.5.1 Connection for power supply.................................................................................................. 22
3.2.5.2 Connecting the external control panel ................................................................................... 24
3.2.5.2.1 Connecting the cable for the external control panel on the ventilation unit........................... 24
3.2.5.2.2 Connecting the cable on the external control panel............................................................... 25
3.2.5.3 Connecting the internal control panel .................................................................................... 26
3.2.5.4 Installing and connecting the sensor module......................................................................... 26

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4
Parameterizable operating modes......................................................................................... 28
3.2.6.1 Configuration of Automatic operating mode........................................................................... 28
3.2.6.2 Configuration of the boost ventilation mode........................................................................... 28
3.2.6.3 Configuration of the Away mode............................................................................................ 28
Installing the exterior wall panel............................................................................................. 28
Maintenance and repair by the qualified personnel............................................................... 30
Inspection and cleaning of enthalpy exchanger..................................................................... 30
Replacing the fans ................................................................................................................. 32
Exchanging the control board ................................................................................................ 32
Visualization of fault notifications........................................................................................... 33
Fault codes in the Fault status............................................................................................... 33
Technical description ............................................................................................................. 33
Pressure loss-Volume flow-Characteristic curves for design of adjoining room connection. 34
Dimensions ............................................................................................................................ 35
Mounting template (figure not true to scale) .......................................................................... 36
Terminal scheme.................................................................................................................... 37
4Appendices........................................................................................................................... 38
Checklist A Maintenance work for users................................................................................ 38
Checklist B Maintenance work for qualified personnel.......................................................... 39
Commissioning and handover protocol.................................................................................. 40
Air volume protocol ................................................................................................................ 41
Product data sheet................................................................................................................. 42
Product label.......................................................................................................................... 44
Conformity.............................................................................................................................. 45
Declaration of conformity of the European Union.................................................................. 45
EAC certificate of the Eurasian Economic Union................................................................... 46

EN 5
0 Preface
Validity
This document applies to:
•Unit type ComfoAir 70 series
The unit type series are hereinafter designated with the common product name, ComfoAir 70.
The subject of this manual is the ComfoAir 70 in its various design variants. Possible accessories are only described to
the extent necessary for appropriate operation of the unit. Please refer to the respective instructions for further information
on accessory parts.
Target group and standard operation
This manual is for users and qualified personnel. The activities are only allowed to be carried out by appropriately trained
personnel who are sufficiently qualified for the respective work involved.
Qualification of target group
0.2.1.1 Users
Users must be instructed by qualified personnel as follows:
• Instruction in hazards when handling electrical devices
• Instruction in the system’s operation
• Instruction in the maintenance of the ComfoAir 70
• Knowledge of and compliance with this manual, including all safety instructions.
0.2.1.2 Qualified personnel
Qualified personnel must have the following qualifications:
• Training in dealing with hazards and risks when installing and operating electrical devices
• Training for the installation and commissioning of electrical devices
• Knowledge of and compliance with the locally applicable building, safety and installation regulations of the relevant
local authorities or municipalities, the regulations of the water and electric utilities, and other official regulations and
guidelines
• Knowledge of and compliance with this document, including all safety instructions
Unless otherwise stated in this manual, only a recognized qualified person is authorized to install, connect up, commission,
and to service the ComfoAir 70.
Standard operation of the unit
This unit can be used by children aged 8 and over and also persons with reduced physical, sensory or mental abilities, or
a lack of experience and knowledge provided that they are under supervision or have been instructed on the safe use of
the unit and understand the risks that result from it. Children must not play with the unit. Children must not carry out cleaning
and user maintenance without supervision.
1 Introduction and safety
The ComfoAir 70 is built to the current state of the art and the recognized safety regulations. The unit is subject to
continuous improvement and development. This is why it is possible for your unit to deviate slightly from the description.
Proper use
ComfoAir 70 ventilation unit
The ComfoAir 70 can be used for comfortable ventilation in living and office areas (with limitations in the commercial sector)
at a normal room air humidity of approx. 40 – 70% RH, briefly up to approx. 80% RH. Any other type of use is considered
as misuse. Extreme conditions (e.g. salty air or air polluted with chlorine) can damage the unit. For reasons of safety, it is
prohibited to modify the product or to install components that are not explicitly recommended or distributed by Zehnder
Group for this product.
Control panels
The ventilation unit is equipped with an internal control panel. As an option, an external control panel can be connected to
the unit using a cable of max. 25 m length. The external control panel is only suitable for use in indoor areas.

EN
6
Safety
Always observe the safety regulations and installation conditions in the current operating manual. Failure to observe the
safety regulations, installation conditions, instructions, warnings, and comments in this document can result in personal
injury or damage to the unit.
Safety regulations
•
Do not make any changes to the unit or to the specifications listed in this document. Such changes can cause
personal injury or lead to reduced performance in the ventilation system
• Always comply with the general locally-applicable building, safety and installation regulations of the relevant local
authorities, the regulations of the water and electric utilities, and all other official regulations
• Installation, commissioning, and maintenance must be carried out by an authorized person or company, unless
otherwise stated in this document
• Always disconnect the unit from the power supply before you start working on the ventilation system
• Following installation, all parts that could lead to personal injury are protected by the housing. The unit cannot be
opened without the use of a tool
• Do not disconnect the unit from the power supply unless instructions to the contrary are listed in the manual
• The control unit can be damaged by static charge; which is why you must always take measures to prevent
electrostatic discharge when handling the control unit (e.g. antistatic wrist strap)
• Replace the filters (at least) every six months. This ensures a pleasant and healthy air quality, and the unit will be
protected against contamination
• Only operate the unit with a closed housing
• Keep this document in the vicinity of the unit during the entire service life of the ventilation unit
Installation conditions
•
Check that the installation area is frost-protected
• The acceptable temperature range for the air being moved is between -20 °C and +40 °C
• The unit must not be installed in rooms subject to explosion hazards
• When installing the unit, make sure that the applicable country-specific standards / regulations for compliance with
protection zones when installing electrical systems in rooms with a bathtub or a shower are observed!
• The unit must not be used for extracting combustible or explosive gases
• The unit must be connected to a fixed 230 VAC / 50-60 Hz power supply
• To switch off from the mains, a disconnection system using a contact opening width in accordance with the
conditions from overvoltage category III for complete disconnection must be provided
• Check whether the electrical installation is suitable for the maximum power of the unit. The values for the electrical
input power can be found in the "Product data sheet" chapter
• Check that the installation area of the unit meets the requirements in the "General installation instructions" chapter
Symbols used
You will find the following symbols in this document:
Important note!
Caution: Risk of affecting the operation of the ventilation system or damaging the unit!
Caution: Risk of personal injury!
Warranty and liability
Warranty provisions
Warranty according to our general terms and conditions (http://www.international.zehnder-systems.com/company/general-
terms-and-conditions). Warranty claims can only be asserted for material defects and/or design faults that have occurred
during the warranty period. Repair work under the warranty conditions is only allowed to be carried out with the prior and
written approval by Zehnder Group. A warranty on spare parts is only then given if those parts have been delivered by the
manufacturer and were installed by a specialist technician recognized by the manufacturer.
The warranty shall be null and void if:
• the warranty period has elapsed
• the unit is operated without filters released by the manufacturer of the ventilation unit
• parts are installed that are not supplied by the manufacturer
• the unit is used improperly

EN 7
• the defects occur as a consequence of an incorrect connection, improper use, or from system contamination
• unauthorized changes or modifications to the system are made
Liability
The ComfoAir 70 was developed and manufactured for the decentralized and semi-centralized ventilation of living areas
and functional rooms.
Every other use is deemed as "improper use", and can lead to damaging the ComfoAir 70, or to personal injury, for which
the manufacturer cannot be held liable. The manufacturer shall not be liable for any kind of damage that can be attributed
to the following causes:
• Failure to observe the instructions listed in this manual pertaining to safety, operation and maintenance
• Improper installation
• Installation of spare parts that were not delivered or stipulated by the manufacturer
• Defects as a consequence of an incorrect connection, improper use or from system contamination
• Normal wear
2 Instructions for the user and qualified personnel
Product description
The ComfoAir 70 is a decentralized or semi-centralized ventilation unit with waste heat recovery for a healthy, well-
balanced, and energy-saving comfort ventilation. The unit can be used as a single room unit (replacing the air in one and
the same room) or as a so-called isolated solution using an adjoining room connection. With this ComfoAir 70 application
as a semi-centralized ventilation system, air can be extracted from the kitchen, bathroom, WC(s) using the adjoining room
connections, and the fresh air introduced into the living room, bedroom, and children's room. The room network is used as
an overflow area.
An enthalpy exchanger, which can transfer both humidity and heat owing to the physical characteristics, is used in the
ComfoAir 70 for the waste heat recovery. The housing consists of a powder-coated steel plate, as well as covers made of
aluminium in the RAL9016 colour scheme. The unit body, made from a high-quality polypropylene, is used for
accommodating the essential unit components, and also makes sure there is the necessary heat insulation and unit
soundproofing.
The ComfoAir 70 has two maintenance-free 24 VDC radial fans with electronic commutation. These fans and the control
board receive the required operating voltage via an integrated 230 VAC / 24 VDC power supply unit.
By default, a filter (in filter class G4) is used in the unit for the outdoor air and the extract air. As an option, filters in class
F7 with pollen filter quality can be used for the outdoor air.
The exterior wall panel is available in three different types of material: white aluminium, white ABS plastic, or stainless
steel.
The ComfoAir 70 has shutters that, under specific working conditions, automatically close off the outdoor air and exhaust
air sections in the unit.

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8
Type label
The type label identifies the product unequivocally. The type label can be found underneath the upper design cover, on
the polypropylene unit core. You will need the details on the type label for the safe use of the product and in case of
questions for service. The type label must be attached permanently on the product.
Frost protection
The ComfoAir 70 is equipped with an automatic frost protection control system, which prevents ice from forming in the heat
exchanger at very low outdoor air temperatures. If needed, the frost protection mode is activated both in the four manual
fan speeds and in the Automatic fan speed.
Item Description
A EPP housing, upper part
B Extract air filter (G4)
C Filter cover made of cellular rubber
D Exterior wall panel (with swelling sealing tape stuck on rear side)
E Wall bracket
F Enthalpy exchanger (diaphragm moisture heat exchanger)
G Connection socket
H EPP housing unit with integrated fans and folding mechanism
I Control board
J Lower design cover made of aluminium, with integrated control panel
K Touch-sensitive control panel
L Outdoor air filter (G4 or F7)
M Filter cover made of cellular rubber
N Upper design cover made of aluminium
A C
B
F
N
M
D
K
J
I
H
L
E
G

EN 9
2.1.2.1 Frost protection mode
In frost protection mode, the ratio between the supply air and extract air volume flow is automatically adjusted depending
on the outside air temperature by the control system, and the unit is shut down if the outside temperature is lower than
-15 °C. A check is made regularly as to whether the temperature conditions in regard of frost protection have changed,
and the respective operating mode (requiring frost protection) is activated automatically according to the result of that
check.
Joint operation with fireplaces
Joint operation with fireplaces depending on the indoor air is only permissible in combination with the corresponding safety
devices and in compliance with applicable laws, regulations, and standards.
Functionality of the internal and external control panel
The control panels have touch-sensitive buttons, which means the respective operating functions are triggered by touching
the relevant buttons. The ComfoAir 70 can be operated at the same time with the internal and the external control panel.
The button assignments and the LED signalling in both control panels are identical in terms of functions.
The two buttons are used for setting the various fan speeds and operating modes. The ventilation stages and the Automatic
operating mode are indicated with blue LEDs, and the service information with red LEDs.
1234
LED
Automatic
Symbol
Automatic
Symbol
Fault
Symbol
Filter replacement
LED
Filter replacement LED Fan speeds
(-) / (+) buttons for
selecting operating
mode / fan speed
LED
Fault
1 2 3 4

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10
Operating functions and signalling from the control panel
Icon Description Explanation
Fan speed
operating mode
The selection for the current fan speed (in total 4 fan speeds with preset
speeds for each fan) is made by using the (-) / (+) buttons.
Touching the (+) button sets the next higher fan speed and touching the
(-) button sets the next lower fan speed.
LED1 lights up
LED1-2 light up
LED1-3 light up
LED1-4 light up
Fan speed 1 (FS1)
Fan speed 2 (FS2)
Fan speed 3 (FS3)
Fan speed 4 (FS4)
AUTO LED lights up
Automatic
operating mode
(AUTO) The Automatic function can only be activated with a sensor
module.
Touching the (+) button from the currently active FS4 transfers the unit
to AUTO fan speed. AUTO fan speed is exited by touching the (-) button,
and the unit is transferred back to FS4. The Automatic function is
visualized by the Automatic LED.
AUTO LED lights up
Bathroom function
operating mode The Bathroom function can only be activated with a sensor
module and configured DIP switch setting.
The fans are operated at maximum speed starting from a relative room
air humidity of 80%. If this limit is not reached, the previously active
operating mode is applied again.

EN 11
LED1-4 light up
Boost ventilation
mode The boost ventilation function as temporarily activated fan
speed 4 can only be activated with a configured DIP switch setting
.
After the boost ventilation time has elapsed, the unit will be transferred
to the most recently selected fan speed. The fan speed that was active
for longer than 10 s is deemed as the last fan speed. When boost
ventilation is active, the operating modes "Extract air mode" or "Supply
air mode", that may be activated, are retained.
The boost ventilation time of 15, 30 or 45 minutes can be set by the
Customer Service with the programming module.
(Factory setting: 15 minutes)
LED1 lights up
during the active
time phase
Away mode The Away function as temporarily activated fan speed 1 can
only be activated with a configured fan speed 1
.
The active operating time of the fan speed 1 of 15, 30, or 45 min/h can
be set with a programming module by customer service.
(Factory setting: 60 min/h ≙FS1 permanent operation).
LED display for
energy-saving
mode
The LED display on the control panel changes after 10 seconds into
energy-saving mode without operator input (unit functions remain active;
the LED display is switched off). If any button is touched, the LED display
will be activated again. Touching the button brings about no change to
the operating mode, however.
Standby mode The unit can be switched from FS1 to Standby mode by touching the (-)
button. The fans then come to a stop.
The shutters are closed automatically!
Standby mode is exited by touching the (+) button. The unit will start with
fan speed 1.
The shutters are opened automatically!
There is no indication of the Standby mode from the LEDs of the control
panel.
LED1 flashes in
alternation with the
current fan speed
Extract air mode Touching the (-) button for 5 seconds in operating modes FS1 to FS4
activates or deactivates the Extract air mode. The supply air fan is
switched off; the extract air fan continues to run with the current fan
speed.
The display for the current fan speed alternates every 2 seconds with the
flashing LED1.
To avoid condensation appearing on the outer panel, the unit
automatically changes to the frost protection mode when the frost
protection temperature is reached. The supply air fan is activated for
several minutes every hour in order to record the correct outside air
temperature.
LED4 flashes in
alternation with the
current fan speed
Supply air mode Touching the (+) button for 5 seconds in operating modes FS1 to FS4
activates or deactivates the Supply air mode. The extract air fan is
switched off; the supply air fan continues to run with the current fan
speed.
If the outdoor temperature falls below 13 °C, the extract air fan will be
activated.
The display for the current fan speed alternates every 2 seconds with the
flashing LED4.

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12
Automatic operating mode
Automatic operating mode requires an internal installation and configuration of a sensor module! The
sensor modules inserted in the extract air section of the ventilation unit are available as optional
accessories.
The Automatic function changes into the frost protection operating mode in the event of frost protection
criteria being met!
The application of the Automatic function follows the logic of a demand controlled system for optimizing the indoor air
quality. Consequently, an optimized response is achieved and mildew formation is prevented, which ultimately also leads
to an increase in energy savings.
The ComfoAir 70 ventilation unit with a sensor module is classified in energy efficiency class A.
LEDs1-3 flash
Flashing of most
recently active fan
speed when supply
air fan is switched
off
(Display of LED1-3
as example)
Frost protection
mode
A temperature threshold, which activates its own frost protection routine
if not reached, is stored for each fan speed. The fan speed of the supply
air will be regulated linearly between the minimum and maximum set
point when the outside temperature is dropping. The fan speed can still
be changed.
The supply air fan is deactivated if a second temperature threshold is not
reached.
If the outside temperature falls below the temperature limit threshold of -
15 °C, the extract air fan will also be deactivated and the unit switched
off.
After the unit is switched off, a flashing in those LEDs (by touching the (-
) or (+) button) which denoted the most recently active fan speed will be
signalled. The fan speed cannot be changed and is signalled with the
flashing of Fault LED.
The shutters are closed and opened automatically
depending on the current frost protection routine!
Fault LED flashes
Indication of
locked modes If an inaccessible operating mode is selected, it will be signalled by the flashing of Fault LED.
These operating modes are the locked standby, locked supply and
extract air mode and complete switch-off due to frost protection.
LED Filter
replacement flashes
Indication of filter
inspection The filters are monitored based on running time. 90 days are preset by default.
After the filter runtime has elapsed, notification in regard of a filter
inspection is signalled by the filter replacement LED flashing.
Simultaneously touching the (-) and (+) button for 3 seconds allows you
to acknowledge the indication of the filter inspection and to reset the filter
runtime.
Fault LED lights up
Error code LED1-4
Signalling of error
code fault
message
If an error occurs, this is signalled by the fault LED.
Faults that can be diagnosed by the unit are symbolized by LED1-4 using
an error code (see 3.4.1).
Simultaneously touching the (-) and (+) button for 3 seconds allows you
to delete the indication of the fault notification.

EN 13
2.3.1.1 Functional principle of HUMIDITY sensor
The HUMIDITY sensor module is primarily supposed to be installed in units for the ventilation of rooms
with an increased occurrence of humidity.
The HUMIDITY sensor module is equipped with a humidity and temperature sensor and calculates the relative humidity.
In the evaluation of the current sensor signal for the setpoint selection, the fans are regulated in accordance with the
characteristic curve in diagram 1. Since the dehumidification performance decreases the smaller the temperature
difference between indoor and outdoor air, at a difference of ΔT < 5 K the air volume is reduced to 20 m³/h. When the
Bathroom function operating mode is active, the unit will be operated with the highest fan speed if the relative humidity
amounts to 80% or more.
Diagram 1: Factory setting characteristic curve for Automatic operating mode with humidity control
2.3.1.2 Functional principle of CO
2
/ VOC sensor
The CO
2
sensor module and the VOC sensor module are each combined with a humidity/temperature
sensor.
The CO
2
sensor module and the VOC sensor module both offer the option to evaluate relative air humidity as well as the
air quality for controlling the ventilation unit. The VOC sensor module detects volatile organic compounds (VOC) and the
CO
2
sensor module, as NDIR sensor (nondispersive infrared sensor), detects carbon dioxide (CO
2
). Volatile organic
compounds correlate really well with the CO
2
concentration in living spaces. In the evaluation of the current sensor signal
for the setpoint selection, the fans are regulated in accordance with the characteristic curve in diagram 2.
Diagram 2: Factory setting characteristic curve for Automatic operating mode with CO
2
/ VOC control
The CO
2
and VOC sensor modules combined with a humidity/temperature sensor can be deactivated
separately if needed, in accordance with the humidity or air quality control. If both sensor modules are
configured as active, the control characteristic of the sensor module is designed with the greater sensor
signal.
The required hardware settings on the control system are only allowed to be made by qualified personnel!
Maintenance by the user
If the maintenance work is not carried out regularly, this will affect the functionality of the decentralized
ventilation unit in the long run!
Replace the filters at least every six months. This ensures a pleasant and healthy air quality, and the unit
will be protected against contamination.
0
10
20
30
40
50
0 102030405060708090100
Volume flow [m³/h]
Rel. humidity [%]
Humidity control
0
10
20
30
40
50
400 600 800 1000 1200 1400 1600 1800 2000
Volume flow [m³/h]
Concentration CO2 [ppm]
CO2 / VOC control

EN
14
The maintenance of the ventilation unit for the user is limited to changing the filters periodically and to cleaning the unit on
the surface, if needed. Check the filters if this is indicated by the filter replacement LED.
Cleaning the surface of the unit, and specifically the control panel, is possible using a damp cloth and a
mild soap solution. Never just wipe it dry!
Unsuitable cleaning agents are:
•Alcohol (> 5%)
•Acetone
•Benzene or carbon tetrachloride
•All types of "strong" cleaning agents
•Scouring agents
•Glass cleaners and similar
Instructions for units with an adjoining room connection!
The filter mats should be replaced or cleaned on the extract air valves (e.g. bathroom, kitchen, WC) every 2 - 3 months or
when checking the degree of contamination at one's own discretion.
Replacing the unit filters
The ComfoAir 70 must not be operated without filters. When changing filters, the unit needs to be
transferred to the Standby operating mode.
In ComfoAir 70, two high-quality original filters of the class G4 are installed by default. Retrofitting a pollen filter of the class
F7 is possible. This is inserted into the lower filter compartment (outdoor air filter). The filters in the ComfoAir 70 must be
checked in accordance with the relevant notification on the control panel and, if needed must be replaced. In doing so,
proceed as follows:
1. Put the unit into the Standby operating mode.
2. Remove the upper design cover by pulling it out of the guides in an upwards direction.
3. Use your finger to go into the recess between the filter cover made of cellular rubber and the EPP housing, and pull
the filter cover out.
Filter compartment for extract air filter (G4)
Filter compartment for outdoor air filter (G4 or F7)

EN 15
4. Gripping the pulling tabs, pull the filter carefully out of the filter compartment.
5. Using the directional arrow of the filter label pointing to the centre of the unit, insert the new filter into the filter
compartment. Make sure that the filter is not pushed into the housing with force.
6. Insert the filter covers again so that the filter compartment is filled evenly.
7. Proceed in the same way for the upper unit filter.
8. Put the upper design cover onto the unit from above. Make sure that it engages, both in the guide for the lower
design cover as well as with the locking nipples, into the designated spring clips of the wall bracket.
9. Switch the unit back into the desired operating mode.
Resetting the filter runtime
After completing the filter replacement, the meter for the filter runtime must be reset. To do this, you can clear the filter
inspection indication again by touching the (-) and (+) button for 3 seconds. The red LED on the control panel, symbolizing
the filter replacement, switches off.
What should I do in case of a malfunction?
Contact the installation technician in case of a malfunction. Note down the type of your ComfoAir 70; for more on this, see
the type label underneath the design cover of the unit.
The mains connection must always be present, providing the ComfoAir 70 does not have to be shut down due to a serious
malfunction, maintenance work, or due to another urgent cause.

EN
16
As soon as a mains disconnection is made, the apartment will no longer be mechanically ventilated. This
makes it possible for problems involving moisture and mould to occur in the apartment. A longer period
of being switched off, particularly during the summer months, brings about the danger of accumulating
contaminants in the inside of the exterior wall panel and in the EPP housing section of the pipe extension!
The ventilation unit must be permanently left in operation, excepting times needed for maintenance and
repair work. The unit should be operated in the Away mode for the duration of an absence!
Disposal
Discuss with your supplier what you should do with your ComfoAir 70 at the end of its life cycle. If you cannot return your
ComfoAir 70, do not deposit it in the normal household waste, but rather contact your local authority for options to recycle
components or to process materials in an environmentally-friendly way.
3 Instructions for the qualified personnel
Installation requirements
The following requirements must be assured for the correct installation:
• Installation in accordance with the general and locally-applicable safety and installation regulations from, among
others, the electric utility, and in accordance with the regulations stipulated in this manual
• Outside wall with final construction thickness of minimum 275 mm
• Sufficient clearance to objects and for maintenance work (at least 10 cm on extract air side, 20 cm on the supply
air side, 80 cm at the front, and 20 cm above the unit), with regard to the housing surfaces when installed
• Recommended suction opening for the outdoor air with respect to the ground >1 m, however, at least unpolluted
air in the suction area
• 230 VAC, 50-60 Hz power supply for fixed units
Transport and packaging
Proceed with care when transporting and unpacking the ComfoAir 70. The ventilation unit and the outer panel are packed
in a transport-safe box.
Do not damage or dispose of the packaging before final installation of the ventilation unit.
Checking the scope of delivery
If damages or incompleteness should be determined at the delivered product, please contact the supplier immediately.
Included in the scope of delivery are:
• ComfoAir 70, including installation kit
• Exterior wall panel, including installation kit
• Mounting template as imprint on the inside of the lid of the box
• Operating and installation instructions
• Product labels for energy-efficiency label
For devices with adjoining room connection, you should use accessories of the Zehnder product portfolio
for installation of the air ducts.
Installation
General installation instructions
The ComfoAir 70 is only designated for installation in an outside wall, whereby the housing for the unit must be on the
inner side, in a vertical position. To mount the ventilation unit, a wall mounting pipe must be installed into the outside wall
in advance; please refer to the respective installation instructions enclosed for the procedure for installing the wall mounting
pipe.
When planning the installation location, please note that the clearance needs to be 10 cm on the extract
air side and 20 cm on the supply air side for the intended operation of the standard variant. For
maintenance work, clearances of 80 cm in front of the unit and 20 cm above the unit are to be adhered to!

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The unit has the protection class IP20. Make sure that the applicable country-specific standards /
regulations for compliance with protection zones when installing the unit in rooms with a bathtub or
shower are observed!
Installation preparations
Prior to installing the ventilation unit, an appropriate wall mounting pipe must already be installed in the outside wall at the
designated installation location. It must be adjusted flush with the level of the finished wall construction.
The installation of the ComfoAir 70 is only allowed in connection with the round wall mounting pipe or with
the square wall mounting pipe!
The square wall mounting pipe, intended in particular for new buildings, should be integrated in the outside wall construction
in the course of the wall construction. The round wall mounting pipe is primarily used in the refurbishment and
reconstruction of the building fabric, and is inserted in the outside wall by means of a core hole (∅270 mm).
Observe the respective enclosed instructions on professional installation when installing the wall
mounting pipe. Use the mounting template in order to transfer all centrings for the holes onto the inner
wall surface.
A 230 VAC mains connection for fixed units is to be prepared on site for the mains power supply.
In order to connect an external control panel, a cable must be installed on site between the control panel
and ventilation unit (recommendation: type J-Y(ST)Y 2x2x0.6 LG indoor cable with colour coding in
accordance with VDE 0815).
The mains supply line (e.g. NYM-J 3x1.5) and, where applicable, the cable to the external control panel, must be installed
flush-mounted up to the area of the bottom left side of the unit. The cable ends should protrude approx. 10 cm out of the
wall surface in the area of the cable entry point.
Connecting the ventilation tubes (only for adjoining room connection)
The installation of the ventilation tubes and the necessary accessories (adapters, bends, sealing tape)
should be done prior to installing the ventilation unit.
The following points must be observed when installing the ventilation tubes:
• You have the choice of installing the ventilation tubes either at the side or behind the unit
• Install the ventilation tubes air-tight at the designated connectors. To do so, use the recommended sealing tape
(accessory items). The sealing tape should be moistened with silicone spray so that the connection for the
ventilation tube with the housing takes place more easily
• In order to install at the back of the unit, remove the blanking plugs from the EPP housing, and install the ventilation
tubes from the other ventilated room. Use the attached blanking plugs, that are covering the room connections
behind the unit in the delivery state, in order to close off the side connections
• Remove the grille by the two webs

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Adjoining room connection from behind:
• Recommendation: Use the "90/75 to flat 51 adapter" and route the duct into the insulation layer of the outside wall
insulation.
Restrictions when installing the flat 51 flat duct on the inner wall!
When using the adapter "90 to flat 51 / bend 90° adapter" (item number 990 322 046), the connecting flat51 flat duct must
be routed in a downward direction, and then only using a 90° angle ("Bend flat 51 H") to the left or to the right.
The reason for this is the fixing point of the wall bracket located next to the respective adjoining room connection, where
the fixing point is not allowed to be located in the vicinity of the flat duct.
An exception here is mounting the unit on drywalls or on an in-wall installation. Since the wall bracket here is fastened on
the drywall, the flat duct can also be routed behind the wall, without having to get into a collision with the short fasteners
(e.g. plasterboard wall plugs) then being used. Please observe the shorter screw or wall plug lengths of maximum 35 mm
to be used then.
For correct installation, the appropriate adapter for the flat51 system must protrude 27 mm out of the wall, so that the
connector is inserted 22 mm in the EPP body following installation.
Adjoining room connection to the side:
• If a side exit for the ventilation tubes is being used, leave the blanking plugs in the behind connector, and only
separate the ventilation grille on the aluminium housing from the required connection side.
Install the connecting pipe flexibly so that, when installed, it can be disconnected from the unit
again for later servicing work (pipe must be able to be withdrawn from the connector)!

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• The self-adhesive sealing tape must be stuck over the entire circumference of the connector on the outside, namely
10 mm away from the front end of the connector. That end of the adapter (together with the stuck-on sealing tape)
is inserted 35 mm into the EPP body for installation purposes.
Make sure, even after plastering the inner wall, that the pipe still protrudes far enough out of the
wall!
• For the connection to the second room, use a d
a
= 100 mm pipe connection, or use the Zehnder flat duct, flat 51,
with the aid of an adapter.
• The ventilation tubes in an adjoining room connection have an effect on the volume flow balance
of the ventilation unit. The balance adjustment must be produced in accordance with the system
characteristics curve by using the PC software.
Installing the ventilation unit
Prior to starting work, ensure that the mains supply line has no voltage!
Check in advance the required carrying capacity of the respective mounting surface (dead weight of the
ComfoAir 70 is 22 kg) and the secure mounting option using wall plugs and screws of sufficient length. The
supplied mounting material should only be considered as a suggestion.
Use the mounting template as an aid for the bore holes. Prior to installing the unit, remove the upper and
lower design covers. Unplug the plug connection for the ribbon cable on the internal control panel.
A sensor module (optional accessories) must be fitted in the unit before the unit is installed!
Proceed as follows for the installation of the unit:
1. Pull the upper outer cover upwards and out of the bracket, and undo the two screws to remove the lower design
cover.

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2. Lift the lower outer cover slightly, and pull the ribbon cable on the inner side of the design cover, gripping the red
plug, carefully off the board of the internal control panel.
3. Remove the wall bracket from the EPP housing so that the unit is now available with no housing components.
4. Drill the four holes in accordance with the mounting template for fixing the wall bracket, and insert the supplied, or,
depending on the wall construction, relevant mounting material (wall plugs) into the holes.
Should the centrings for the bore holes not be available, the drill holes can be transferred
afterwards onto the inner wall surface by means of vertical alignment and central application of the wall
bracket in relation to the pipe axis!
5. Screw the wall bracket to the inner wall, and take care to ensure that the mains supply line and, if present, the cable
for the external control panel, are guided through in the area of the cable entry point.
If the inner wall surfaces are uneven, or it is not vertical, then the wall bracket must be aligned
using suitable tools (spacers or something similar).
6. Connect the power supply in the connection socket in accordance with 3.2.5.1 and, if present, connect the external
control panel on the unit side, in terms of the plug-in connector part with the screw-type terminals in accordance
with 3.2.5.2.1.
7. If necessary, shorten the EPP pipe to the length of the wall mounting pipe +5 mm, or the wall thickness, so that it
is also flush with the façade.