Airflow Duplexvent Flexi DV1100 User manual

Installation, use and
maintenance manual
for
Duplexvent Flexi
DV1100,1600, 2600, 3600

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Dear customer,
Thank you for choosing our product and we hope that you will be fully satisfied.
This manual contains all necessary instructions, information, hints and recommendations for safe and correct equipment installation
and commissioning. Please read the manual carefully and follow the instructions contained herein.
Symbols explained
Items or sections marked with  ( or with a grey background) apply only to appliances manufactured in compliance with the hygienic
requirements of Regulation VDI 6022 (indicated on the identification plate, see following chapters).
Important notices
●Electrical connections, commissioning and adjustment of the appliance may only be carried out by qualified electrical
engineers.
●Before the installation and commissioning of the appliance carefully read the installation, use and maintenance
manual, the controller operation manual and, where applicable, the service documentation.
●The appliance and all its accessories must be installed and used in compliance with the design, technical conditions
specified by the manufacturer and applicable legislation and technical standards in effect.
●The appliance may not be installed and operated in an aggressive environment that could damage its external and
internal mechanical parts.
●Before putting the appliance into permanent operation an initial inspection report on the appliance´s power supply
must be provided.
Before putting the appliance into operation an approval test (see VDI 2079 and DIN EN V 12599) of the entire HVAC
system of which the appliance forms part must be conducted. The test must include the examination of hygienic
requirements as per VDI 6022 and must be documented. The user must be able to present the approval test report at any
time. If the above requirements are not met, the manufacturer cannot ensure compliance with hygienic requirements.
The manufacturer is not liable for damage caused by unprofessional installation and operation that
is not in compliance with the operation and maintenance manual and general practices applied
during installation and operation of HVAC equipment and control systems.

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1. Content
1. Content ........................................................................................................................................................................................3
2. Safety instructions........................................................................................................................................................................4
2.1 General safety...............................................................................................................................................................................4
2.2 Operational safety .........................................................................................................................................................................4
3. Storage and transport ..................................................................................................................................................................4
4. Description ...................................................................................................................................................................................5
4.1 General .........................................................................................................................................................................................5
4.2 Intended use .................................................................................................................................................................................5
5. Installation....................................................................................................................................................................................5
5.1 Safety instructions.........................................................................................................................................................................5
5.2 Hygienic instructions for the appliance as per VDI 6022 ...............................................................................................................5
5.3 Identification of ports, connecting the HVAC duct .........................................................................................................................6
5.4 Installation steps ...........................................................................................................................................................................6
5.5 Adjusting the unit - turning ports e2 (SUP) / i2 (EHA)....................................................................................................................7
5.6 Connecting the condensate drain pipe ..........................................................................................................................................7
5.7 Classification of air filters...............................................................................................................................................................8
5.8 Installing air filters..........................................................................................................................................................................8
5.9 Installation, connecting and filling of liquid manometers (optional accessory)...............................................................................9
5.10 Installation and connecting of the hot water air heater (optional accessory) .............................................................................10
5.11 Installation and connecting of the control set of the hot water air heater (optional accessory) ..................................................10
5.12 Installation and connecting of shut-off dampers e1, i1 (optional accessory) .............................................................................10
5.13 Installation of flexible flanges (optional accessory) ...................................................................................................................10
5.14 Installation and connecting of the water chiller to the cool source (optional accessory)............................................................10
5.15 Installation and connection of the control manifold of the water-cooled chiller (optional accessory) .........................................11
5.16 Installation and connecting of the direct chiller (optional accessory).........................................................................................11
5.17 Installation and connecting of the electric heater / pre-heater EPO-V (optional accessory) ......................................................11
5.18 Installation and connecting of manostats to control constant flow rates and pressure (optional accessory) .............................11
6. Electrical connection, commissioning, description of controls....................................................................................................11
7. Hygienic instructions for the appliance as per VDI 6022 ............................................................................................................12
7.1 General instructions ....................................................................................................................................................................12
7.2 Required qualifications of personnel as per the type of activity...................................................................................................12
8. Inspecting the appliance ............................................................................................................................................................13
8.1 Overview of inspections and measures to ensure compliance with hygiene requirements .........................................................13
9. Cleaning and maintenance ........................................................................................................................................................14
9.1 General .......................................................................................................................................................................................14
9.2 Cleaning the cabinet....................................................................................................................................................................14
9.3 Air filters, replacing filter cassettes ..............................................................................................................................................14
9.4 Cleaning heat exchangers (heater / chiller).................................................................................................................................15
9.5 Cleaning the plastic heat recovery exchanger.............................................................................................................................15
9.6 Draining and inspection of the condensate collection tank (not included in delivery) ..................................................................15
9.7 Other minor maintenance............................................................................................................................................................15
10. Failures and troubleshooting......................................................................................................................................................15
11. Repairs, spare parts...................................................................................................................................................................16
12. Warranty.....................................................................................................................................................................................16
13. Visual appendix - manuals .........................................................................................................................................................17
13.1 Connecting the condensate drain line .......................................................................................................................................17
13.2 Rotating the fan.........................................................................................................................................................................18
13.3 Fitting the filters.........................................................................................................................................................................19

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2. Safety instructions
2.1 General safety
● Only adults sufficiently familiar with the operation and maintenance manual may operate the equipment.
● The user must not tamper with or modify any part of the equipment, particularly the power supply lines!
● Only professional service technicians with relevant qualifications may perform equipment repairs. Unprofessional repairs are
very risky and may result in loss of warranty.
● Before opening the equipment´s door for cleaning, filter replacement or general maintenance always make sure that the
equipment is disconnected from power supply and prevent its reconnection by another person.
● To prevent injuries caused by the fan wheel, a duct at least 2 metres long must always be connected to the fan discharge. The
duct must be fastened in such a way that it cannot be removed without tools.
● If the equipment has been out of operation for a prolonged period of time, extra care should be taken when putting it back into
operation.
2.2 Operational safety
● The indoor version of the unit is intended for a basic environment - ambient temperatures must be between +5 and +55 °C with
relative humidity up to 60 %. If the appliance is located elsewhere, its sufficient protection must be ensured.
● The appliance may be operated within the temperature range of ventilation air between -25 and +40 °C with relative exhaust air
humidity up to 95%, in an environment where there is no risk of fire or an explosion of flammable gases and fumes, and air
transported must not contain organic solvents or aggressive substances that might damage mechanical parts of the unit. If there
is a danger of such gases and fumes temporarily entering the duct system (e.g. during floor bonding, painting), the unit must be
switched off sufficiently in advance.
● In the event of a failure the appliance must be disconnected from power supply as soon as possible!
● The water chiller in all versions must be filled with an anti-freeze solution with sufficient thermal resistance, or it must be drained
for the period during which outdoor temperature might fall below +5°C. We recommend draining water from the chiller with
pressurized air, not using a gravity flow!
● Appliances with hot water heaters
-Must be permanently connected to power supply to provide for the anti-freeze protection of the hot water heater. In the case
of a prolonged power outage the heating medium must be drained from the hot water heater including the control set. We
recommend draining water from the heater with pressurized air, not using a gravity flow!
-It may only be operated if the heating system including the hot water heater and control set are filled with a heating medium
and air bled; also applies to periods outside the heating season! In the case when the heating system including the hot
water heater and control set are not filled with a heating medium, the appliance must be drained of the remaining heating
medium, dried properly and disconnected from power supply.
● The appliance is designed for environments with Class ETA 1 extract air; in environments with extract air Class ETA 2 and ETA 3
it is necessary to comply with conditions specified in paragraph 5.2
3. Storage and transport
● The appliance may only be stored in dry, covered places with ambient temperatures between -25 and 55 °C in such a way that
its surfaces that are to be in contact with transported air remain protected against the weather and stay dry and clean.
● Packaging may not be removed until immediately before the installation of the appliance in its operating position. If that is not the
case, all parts must be checked for cleanliness before installation and thoroughly cleaned if necessary.
● The appliance must not contain any operational liquids (e.g. water in the hot water heater, water chiller etc.) during storage and
transport.
● The appliance may only be transported on handling blocks (included). During transportation the appliance must be protected
against mechanical damage and water penetration and all openings must be covered with protective covers.
● During transportation the appliance must be secured against falling. The mode of transport must also eliminate any falls of the
appliance or instances of the appliance getting loose.
● Activities near the unit such as grinding, cutting and other ancillary works that could irretrievably damage the surface or
individual parts of the unit are prohibited.

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Solely permitted methods of handling
4. Description
4.1 General
● DUPLEXVENT Flexi series ventilation units with heat recovery are compact appliances containing in a single cabinet two
independently powered fans with flexibly mounted engines, a highly efficient heat recovery exchanger assembled from thin-
walled plastic boards for the recovery of heat/cool, a by-pass damper, slide-out filters and drainage trays, and depending on
accessories selected also an external heater, chiller, shut-off dampers, flexible flanges and a control system.
4.2 Intended use
● DUPLEXVENT Flexi series ventilation units with heat recovery are intended for the comfort ventilation and possibly hot-air
heating and cooling of flats and houses, small plants, workshops, schools, restaurants, cooking facilities and industrial halls with
a basic environment. If the appliance is used for different purposes or is not operated in compliance with instructions contained in
the operation and maintenance manual, the manufacturer is not liable for resulting damages.
5. Installation
5.1 Safety instructions
● During installation make sure no damage or deformation is caused to the case of the appliance (e.g. as a result of handling
operations).
● After setting the appliance in place check it for stability and secure it in this position against moving.
● During handling and installation observe all rules of safe work (including work at heights and work with suspended loads) and
use appropriate work and safety equipment.
● Lifting and binding equipment may only be operated by trained personnel.
5.2 Hygienic instructions for the appliance as per VDI 6022
● If installation is interrupted or heavy dusting occurs, cover all openings of the appliance in such a way so as to ensure that
surfaces to be in contact with transported air remain protected against the weather and stay clean and dry.
● If long-term high relative humidity (short-term more than 90 % or more than 80 % for three consecutive days) is likely to occur
with the subsequent moistening of filters (e.g. in areas with frequent fogs, frequent and long rains, flying snow etc.), suitable
measures must be taken to prevent micro-biologic growth. Recommended measures include more frequent hygienic checks as
per VDI 6022 or shorter filter replacement intervals. Another option is the preheating of air using an appropriate control device
(electrical duct heaters are an available accessory), or the appliance must be put out of operation for the period when filters are
at the risk of moistening (if the type of operation allows this).
● Should such weather conditions occur at the site of installation that would cause the dew point to be exceeded in the supply air
region of the heat recovery exchanger, or an independent cooling system is installed in ventilated rooms, DUPLEXVENT Flexi
units may only be used provided that it has been arranged via appropriate measures that the dew point will not be exceeded in
the heat recovery exchanger. The typical weather of central Europe makes this condition almost impossible.
● The e1/ODA air supply chamber has no water drain. An accessible and cleanable chamber with a drain of precipitated water
must be installed upstream the outdoor air inlet into the appliance.
● The HVAC network of appliances operated in an environment with Class ETA 2 extract air must be arranged for operation in such
a way so that positive pressure is on the supply air side of the heat recovery unit; in an environment with Class ETA 3 extract air
must be arranged for operation in such a way so that positive pressure is on the supply side against the exhaust side. This must
be ensured under all operating conditions of the system. For details see EN 13779.
In compliance with hygienic standard VDI 6022 HVAC systems must be equipped with shut-off dampers to ensure the automatic
closure of the system so that no air can flow freely through the system. It is recommended using shut-off dampers available as
an accessory. Compliance with this requirement is the responsibility of the planner / specialist installation firm.

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DUPLEXVENT series appliances have a single-stage filtration system. Appliances in a hygienic version in compliance with
hygienic standard VDI 6022 must have an Class F7 filter fitted on the inlet (applies to outdoor air e1/ODA Class ODA 1 and
ODA 2). When outdoor air is Class 3, a Class F5 filter must be fitted in the duct upstream the outdoor air inlet into the
HVAC unit; alternatively, a Class F5 filter may be installed in the HVAC unit and a Class F7 filter in the duct at the e2/SUP
outlet from the unit. Note: F5 and F7 filters are separately supplied accessories.
Appliances in a hygienic version in compliance with hygienic standard VDI 6022 may be operated only if the use of recirculating
air is suitable for hygienic reasons or the arrangement of operation of the HVAC network ensures positive pressure in the supply
section of the appliance against the extraction section
5.3 Identification of ports, connecting the HVAC duct
● The versatile design of sizes 1100, 1600, 2600 and 3600 allows adjusting the direction of air flow through the appliance. Identify
and label individual ports using the pictures below (labels are included). Begin by identifying port e1 (ODA) - outdoor air inlet;
continue toward the fan on the same (shorter) side of the unit with exhaust air outlet port i2 (EHA); next is the port with fan on the
opposite side of the unit - supply air outlet e2 (SUP); the last (remaining) port is extract air inlet port i1 (ETA).
Note: Depending on a specific location of the unit proceed clockwise or anticlockwise.
● Connect the HVAC duct following the design documentation.
● To prevent injuries caused by the fan wheel, an HVAC duct at least 2 metres long must always be connected to the unit. The
duct must be fastened in such a way that it cannot be removed without tools.
ATTENTION: For the unit to reach performance levels stated by the manufacturer a straight duct at least 1 meter long must be
connected to all outlet ports. The duct connected to inlet ports must be arranged in such a way so as to allow a
uniform flow rate across the entire section of inlet ports.
5.4 Installation steps
● Before installation remove the wooden transport planks.
● The versatile design of 1100, 1600, 2600 and 3600 sizes allows mounting the unit under the window or under the ceiling.
● Fit the appliance in such a way that the prescribed handling spaces are observed:
View from the operator's side - windowsill position Under-ceiling position

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Plan view - windowsill position
Window position:
-The appliance is placed on height-adjustable feet (Hmin = 147 mm) included in delivery (4 pieces in size 1100, 5 pcs in size
1600, 6 pcs in sizes 2600 and 3600).
-Due to the condensate drain the appliance must be sloped toward section i2 (EHA).
Ceiling position:
-The appliance is suspended from anchors of sufficient load bearing capacity (provided by the building contractor) using four
(sizes 1100, 1600 and 2600), and six (size 3600) suspension eyes (included in delivery) with Ø 11 mm holes.
-Due to the condensate drain the appliance must be sloped toward section i2 (EHA), see the picture.
5.5 Adjusting the unit - turning ports e2 (SUP) / i2 (EHA)
● Only units up to size 1600 can be adjusted that way.
● When making the adjustment, follow the diagram below and the visual instructions in the appendix.
5.6 Connecting the condensate drain pipe
● The unit is versatile and in total has 4 condensate outlets for 2 directions of air flow and 2 installation positions. A single specific
condensate outlet is always used for a particular application.
-For the window position use the condensate outlet in section i2 (EHA)
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DUPLEXVENT Flexi
1100
1600
2600
3600
L (mm)
1700
2020
2150
2450

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-For the ceiling position use the condensate outlet in section i2 (EHA)
● Connect a pipe or hose (not included; a standard washing machine hose is recommended) to the condensate outlet and shape it
into a siphon trap with dimensions as shown in the picture. Appropriately secure the siphon trap shape and connect it to the
sewer line.
● Check the entire length of the pipe including the parts inside the unit for free passage and its sloping.
● Prime the condensate drain siphon trap.
5.7 Classification of air filters
● IF the unit is fitted with filters of various filtration grades (F7 and F5), then the F7 grade filter is an outdoor air filter (ODA) and the
F5 grade filter is an extract air filter (ETA).
● The outdoor air filter is installed in chamber e1 (ODA), the extract air filter in chamber i1 (ETA).
5.8 Installing air filters
● The unit is supplied with separately packaged filter cassettes. Remove and unpack the cassettes and check their condition.
Then install the cassettes in their proper locations on the unit as shown in 5.7.
Unpack and install air filters last, immediately before putting the unit into service to avoid their contamination.
● Should any damage or contamination be detected, replace them with new ones. Spare filter cassettes are to be ordered from the
supplier. The suppliers address and the spare cassette part number are shown on the identification plate of the unit.
● Insert undamaged clean filters into the guide rails and secure following the instructions in the pictures:

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● Especially make sure that the arrow showing the direction of air flow through the filter cassette can be seen from the side of the
operator (the arrow is by the unit´s door) and that it is always pointing toward the heat recovery exchanger!
● The unit is supplied with filter cassette labels unattached. Attach the relevant identification labels near both filters. (e.g. for the
door type)
ATTENTION: Unpack and install air filters last, immediately before putting the unit into service to avoid their contamination.
ATTENTION: Use original filter cassettes only! If different cassettes were used, the manufacturer could not guarantee their proper
function!
Record the date of installing filters appropriately in e.g. the operational
logbook.
5.9 Installation, connecting and filling of liquid manometers (optional accessory)
Liquid manometers are a separately supplied accessory. Manometers are compulsory for hygienic units in compliance with
VDI6022.
● Manometers are used for measuring the pressure loss of air filters. During installation follow the visual instructions supplied with
this optional accessory. After installation level the manometers horizontally.
● Connect the manometers to collection points on the unit's surface using tubes. Connect the tube to the top of the manometer and
run it to the metal bushing on the unit's surface (also see a separate manometer installation manual). The tube must always
connect two matching connection points identified by symbols “+” and “F+” and “-“ and “F-“ (cannot be combined). Make sure that
tubes from just one filter are connected to the manometer.
Attach the relevant label near each manometer. Fill out the boxes with the filter grade and record the flow rates and pressure
losses of the clean filter (initial pressure loss) and when clogged (final pressure loss) using data from the table below; the values
must be adjusted on the basis on actual air flow rates through the unit. The unattached label without information filled out is
included.
● DUPLEXVENT Flexi DV1100
Filter type
Flow rate (m3/h)
250
500
750
1000
1100
F7
Initial pressure
loss (Pa)
Final pressure loss
(Pa)
200
200
200
200
200
F5
Initial pressure
loss (Pa)
Final pressure loss
(Pa)
200
200
200
200
200
DUPLEXVENT Flexi DV1600
Filter type
Flow rate (m3/h)
400
800
1200
1500
1600
F7
Initial pressure
loss (Pa)
16
43
84
126
142
Final pressure loss
(Pa)
200
200
200
200
200
F5
Initial pressure
loss (Pa)
6
14
25
38
43
Final pressure loss
(Pa)
200
200
200
200
200
DUPLEXVENT Flexi DV2600
Filter type
Flow rate (m3/h)
500
1000
1500
2000
2500
2600
F7
Initial pressure
loss (Pa)
10
34
60
91
125
133
Final pressure loss
(Pa)
200
200
200
200
200
200
F5
Initial pressure
loss (Pa)
1
8
17
29
44
47
Final pressure loss
(Pa)
200
200
200
200
200
200
DUPLEXVENT Flexi DV3600
Filter type
Volume flow
rate (m3/h)
700
1400
2100
2800
3500
3600
F7
Initial pressure
loss (Pa)
14
40
77
126
186
196
Final pressure
loss (Pa)
200
200
200
200
200
200
F5
Initial pressure
loss (Pa)
3
11
24
42
65
69
Final pressure loss
(Pa)
200
200
200
200
200
200

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Note: Values in the tables apply to external static pressure 200 Pa. Different pressure requirements may result in a different
situation. If needed, the detailed initial and final pressure loss data of the filters are available on request from the supplier of the
unit.
● Make sure that the position of the label makes it possible to regularly inspect the values recorded.
● Unscrew the rotating knob as much as possible to set zero on the scale (the bottom knob identified by - +), then screw it back by
approximately two full turns to have leeway to make settings in both directions.
● Unscrew the FILL plug (the top knob) and keep filling the machine with measuring liquid (included in delivery) until the liquid is
visible near the zero mark on the scale. Use the bottom knob to set the value on the scale precisely to zero. Screw the top filling
plug in.
ATTENTION: After installing the manometers do not tilt the machine or the door (if they are installed on the door). Measurement
liquid might leak out
5.10 Installation and connecting of the hot water air heater (optional accessory)
● During the mechanical installation of the hot water air heater follow the manual supplied with this optional accessory.
The following rules must be adhered to during the installation of the heater:
● The maximum permitted temperature of heating medium is 110 °C and operational positive pressure up to 1.0 MPa.
● For the proper operation of the control set of the hot water heater, the heating system must be fitted with a circulation pump of
suitable power that will fully cover its pressure losses. The pump, which is supplied with the control set, is designed solely to
cover the pressure losses of the water heater!
● If the unit is not equipped with a shut-off damper on outdoor air inlet e1, a tight shut-off damper must be installed in the duct
upstream the unit (a type with a servo drive with emergency stop, that is, that automatically shuts in the event of a power outage).
● The inlet of the heating system into the unit must be equipped with a sludge filter.
5.11 Installation and connecting of the control set of the hot water air heater (optional
accessory)
● During the mechanical installation and connection of the control set of the hot water air heater follow the manual supplied with
this optional accessory.
5.12 Installation and connecting of shut-off dampers e1, i1 (optional accessory)
● During the mechanical installation and connection of the servo drive of shut-off dampers follow the manual supplied with this
optional accessory.
5.13 Installation of flexible flanges (optional accessory)
● During the mechanical installation of flexible flanges follow the manual supplied with this optional accessory.
5.14 Installation and connecting of the water chiller to the cool source (optional accessory)
● During the mechanical installation of the water chiller follow the manual supplied with this optional accessory.
ATTENTION: For the appliance to work properly and safely it is necessary to correctly connect a condensate drain line!
● Connect a tube or a hose to the condensate drain outlet (not supplied; we recommend using a conventional washing machine
hose) and shape it into a trap. Install the trap with respect to the mounting position (see the pictures below), with the trap size
according to chapter 5.6. Secure the trap shape suitably and run the condensate drain line into a drain outlet.
Ceiling-suspended position Windowsill position