ZILA KST-20 Vento Service manual

mounting and operating instructions
KST-20 Vento | KST-20 Vento/CO2 |KST-20 Vento/RN
climate controller
ZILA GmbH
Neuer Friedberg 5
98527 Suhl
Tel.: [phone]
Fax: [phone]
Web: www.zila.de
E-Mail: [e-mail]

Climate Controller KST-20 Vento | KST-20 Vento/CO2 | KST-20 Vento/RN
Handbook Version: ENG_05052020_ANHU_KST20VENTO| 2

Climate Controller KST-20 Vento | KST-20 Vento/CO2 | KST-20 Vento/RN
Handbook Version: ENG_05052020_ANHU_KST20VENTO| 3
Index
1. scope of delivery ................................... 3
2. General notes ........................................ 3
2.1. installation personnel ............................ 4
2.2. Used Pictograms.................................... 4
2.3. Intended use.......................................... 4
2.4. Foreseeable misuse ............................... 4
2.5. Safety Instructions................................. 4
3. product description ............................... 5
3.1. Technical specifications ......................... 5
3.2. Standards and Regulations .................... 5
3.3. aH-Controlled Technology ..................... 5
3.4. Operating modes................................... 5
3.4.1. Dehumidifying (E) ....................... 5
3.4.2. Ventilation (L) ............................. 7
3.4.3. Cooling (K) .................................. 8
3.5. Comfort functions ................................. 9
4. assembly and commissioning ................ 9
5. connection of the actuators ................ 11
5.1. Control electronics .............................. 11
5.2. Connection variants............................. 12
6. device functions .................................. 12
6.1. Factory settings ................................... 12
6.2. Display illumination ............................. 13
6.3. Functions of the keys........................... 13
6.4. Menu navigation and configuration .... 13
6.4.1. operating mode ........................ 14
6.4.2. actuators................................... 14
6.4.3. antifreeze temperature (FS) ..... 15
6.4.4. Timer (Suhr).............................. 15
6.4.5. dry protection (TS).................... 15
6.4.6. Time.......................................... 15
6.4.7. Date .......................................... 15
6.4.8. target moisture ......................... 15
6.4.9. Delta aH .................................... 15
6.4.10. Cool -TSP................................... 16
6.4.11. Speed Min/Max ........................ 16
6.4.12. LEDs .......................................... 16
6.4.13. Error indication on the display.. 16
7. circuit diagrams ................................... 16
8. additions to the KST-20 Vento/CO2..... 18
8.1. actuators ............................................. 18
8.2. CO2- Measurement ............................. 18
8.3. Connection of the sensors ................... 18
9. additions to the KST-20 Vento /RN...... 19
9.1. actuators ............................................. 19
9.2. Radon measurement ........................... 19
9.3. Connection of the sensors ................... 19
10.device support..................................... 20
1. scope of delivery
•Climate Control KST-20 Vento
•Power cable
•Climate sensor inside (integrated or
detached)
•Climate sensor outside (detached, max. 10m
cable)
•mounting and operating instructions
•2-pole plug (terminal 5)
•Wall mounting set
Components for device version RN or CO2
•Radon sensor (KST-20 Vento/RN)
•CO2-Sensor, integrated or detached (KST-20
Vento/CO2
2. General notes
•Read safety instructions and keep the manual
•Installation, commissioning, electrical
connection and repairs of the KST-20 Vento
are only permitted by qualified persons.
•The specified protection class is only
guaranteed if the cables are installed in the
correct position and correctly inserted and
connected.
•Only operate the device at the specified
voltage
•Modification and conversion of the device is
not permitted and releases ZILA GmbH from
any warranty and liability

Please read these installation
instructions carefully before using
the KST-
20 Vento air conditioning
control unit. Follow the instructions.
Keep these installation instructions in
a safe place for future use.

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2.1. installation personnel
Installation only by qualified persons.
The electrical connection should only be done by
qualified electricians. They have an electrotechnical
training and the knowledge of the dangers and
effects that can be caused by an electric shock.
2.2. Used Pictograms
DANGER
Imminent danger, which leads to
serious injury or death if not
observed.
CAUTION
Potentially dangerous situation
that could lead to minor to
moderate physical injury.
ATTENTION
Possible situation that could lead
to material damage to the product
or its surroundings.
INFO symbol for important
information and tips.
●
Enumeration symbol for
information on the respective
topic.
1.
Instructions. Carry out the
specified instructions in sequence.
2.3. Intended use
The unit is used for the automatic and controlled
activation of supply air and exhaust air elements for
dehumidification, ventilation or cooling of cellars,
storage and supply rooms, showrooms, offices,
changing rooms and similar rooms.
Typical applications
•Dehumidification of rooms and buildings,
such as cellars, archives, museums, churches
•Cooling of production halls and server rooms
•Ventilation of living spaces according to DIN
1946-6
•Ventilation of meeting and classrooms,
sports halls and fitness studios
Operation is only permitted when:
•Fixed installation within buildings.
•Installation on a suitable wall.
2.4. Foreseeable misuse
ZILA is not liable for damages caused by improper
use. Do not use the device under the following
circumstances:
•in the vicinity of flammable materials, liquids
or gases
•in potentially explosive atmospheres
•in outdoor areas without further protection
2.5. Safety Instructions
•Installation and electrical connection only by
qualified persons.
•Read these operating instructions carefully
before commissioning.
•Only operate the device with the voltage and
frequency specified on the type plate.
•Do not make any changes to the device.
•Never operate the device without the
electronics cover.

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3. product description
The KST-20 Vento is a climate control with "aH-
Controlled" technology for demand-oriented
ventilation of private, commercial and industrial
rooms of all kinds.
By means of the connected sensors the climatic
conditions in the inside and outside area are
determined and compared. According to the
measured climatic conditions and the desired
operating mode (dehumidification, cooling,
ventilation), the unit controls supply air and exhaust
air elements in a controlled manner. Additional
dehumidification, drying or cooling systems can also
be controlled.
Due to the integrated device functions and the large
number of connectable devices, such as fans,
window openers, louvre dampers, condensation
dryers etc., the KST-20 Vento can be used flexibly in
almost all living, working and industrial areas.
3.1. Technical specifications
•Power supply: 230V AC
•Protection class: IP 65
•Dimensions in mm (LxWxH): 160 x 90 x 50
•Separate connections for 230 V supply and
exhaust air elements up to maximum 500 W
•0…10 V control outputs (alternative to230 V)
•Operating and surrounding conditions:
0…50°c
Further technical specifications can be found in the
product-specific data sheet on our website
https://zila.de/.
3.2. Standards and Regulations
The KST-20 Vento climate control system complies
with the EMC directive 2014/30/EU under
consideration of the following standards:
•EN 55014-1
•EN 55014-2
•EN 61000-6-2
3.3. aH-Controlled Technology
The basic principle of ZILA climate control systems
is based on the comparison of the water vapour
content of indoor and outdoor air.
The water vapor content is described by the
absolute humidity (aH = absolute Humidity) and
represents a dimension for the "actual" humidity in
the air. The comparison of the absolute humidity of
indoor and outdoor climate ensures that humid air
is removed from rooms and only drier outdoor air is
introduced.
"aH-Controlled" stands for the automated
determination of suitable times for switching on the
supply air and exhaust air elements by the climate
control system, takes the climatic conditions inside
and outside the building into account.
The climate control system controls the most
common single-stage, two-stage and speed-
controlled fans as well as motor-driven window
openers and ventilation louvres fully automatically.
aH-Controlled ensures a healthy building and a good
indoor climate and also works extremely energy-
efficiently, as the building is only ventilated when it
is necessary and air exchange is useful.
3.4. Operating modes
With the KST-20 Vento you can choose between
three operating modes: dehumidification,
ventilation according to DIN 1946-6 and cooling.
Note:
To avoid failures and for optimum
control behaviour of the KST-20
Vento climate control system, the
actuator system suitable for the
respective operating mode must be
used.
3.4.1. Dehumidifying (E)
The KST-20 Vento climate control system is suitable
in dehumidifying mode for mould prevention and

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building protection as well as for maintaining a
comfortable climate.
Controlled dehumidification is based on the
comparison of absolute humidity. In this process,
moist room air is exchanged with drier outside air.
During normal operation, the following climate
information is shown on the display:
•Relative humidity indoor/outdoor (rHi, rHa)
•Temperature inside/outside (Ti, Ta)
•Absolute humidity inside/outside (aHi,aHa)
The KST-20 Vento starts room dehumidification as
soon as the absolute outside humidity is lower than
the absolute inside humidity (aHinside < aHoutside). The
room is dehumidified in a ventilation cycle
consisting of an active and a passive phase. The fan
is switched on in the active phase. During the
passive phase, the fan is off and the room air
contaminated with moisture can mix with the
supplied drier outside air. This permanent shock
ventilation ensures efficient room dehumidification
as long as the climatic conditions aHinside < aHoutside
are fulfilled. A ventilation cycle for both the active
and passive phases lasts 10 minutes. Depending on
the type of fan, there are different possibilities for
speed control.
Further information:
For information on the factory
settings, refer to the "Factory
settings" chapter
dehumidification by 1-stage fans
The KST-20 Vento works as an intelligent power
switch and controls the active and passive phases of
1-stage fans.
Dehumidification with 2-stage fans
2-stage fans can be operated at either a reduced or
an increased speed during the active phase. The
KST-20 Vento switches on the second stage if the
following climatic conditions are given:
aHinside > aHoutside+5g/m³.
Dehumidification with speed-controlled fans
Speed-controlled fans are operated within the two
adjustable limits "minimum speed" (DZMIN) and
"maximum speed" (DZMAX). The speed
corresponds to the control voltage in percent. The
lower limit DZMIN starts by default at aHinside >
aHoutside +0,2g/m³. The upper speed limit DZMAX is
activated at aHinside > aHoutside+10g/m³. In between,
the output of the control voltage is linear.

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Definition of the speed:
The speed is defined at the
beginning of an active phase and is
maintained during this phase.
Therefore,
the speed is only
adjusted again with a new active
phase.
Dehumidification with electric window openers
Since motor-driven window openers only allow a
limited number of switching operations, with this
type of dehumidification the supply air and exhaust
air elements remain switched on until the absolute
humidity outside is no longer lower than inside.
Electric window openers:
The electrical control of window
openers is different from that of
the actuators mentioned above.
To avoid
malfunctions, it is
essential to observe the
corresponding circuit diagram
and the correct actuator selection
for the operating mode.
ATTENTION
A ventilation interval does not take place if the
temperature falls below the set frost protection
temperature or the dry protection humidity.
Further information:
Further information on dry and frost
protection can be found in section
3.5 „Comfort functions“
Restricted use in case of defects in
building physics.
In the case of defects in building
physics, water often penetrates
through walls and the floor into the
affected room. In such cases, the
KST-
20 Vento climate control
system can be used as a supplement
for dehumidification.
The unit supports the drying of
masonry by means of a controlled
air exchange, but cannot achieve
complete dehumidification on its
own.
3.4.2. Ventilation (L)
For living spaces, the device can be used in
accordance with DIN standard 1946-6.
The KST-20 Vento climate control system then
controls two-stage and speed-controlled fans in the
basic ventilation and in an increased ventilation.
The connection of 2-stage or speed-controlled fans
is necessary for this.
Interruption of the basic
ventilation.
Basic ventilation can only be
interrupted by pressing the PAUSE
key on the air conditioning control.
Ventilation with 1-stage fans
Ventilation with 1-stage fans is not supported.
Ventilation with 2-stage fans
The climate control KST-20 Vento always controls
the ventilation fans in the first stage (basic
ventilation).
The increased ventilation stage sets in if aHinside >
aHoutside + ∆aH and if the relative humidity in the
interior is higher than the desired or target humidity
(rHinside> rfw).

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∆aH stands for the minimum distance between the
absolute humidity inside and outside. The default
value is 5g/m³.
The desired humidity describes a desired humidity
level in the concerned room, which must be
maintained by the climate control system. The input
range is between 40% and 60% of the relative
humidity. This can be adjusted in 5% steps.
Ventilation with speed-controlled fans
In basic ventilation, the KST-20 Vento climate
control system controls the speed-controlled fans at
the minimum speed (DZMIN). To reach the
maximum speed, the climatic condition aHinside =
aHoutside+10g/m³ must be fulfilled.
In between, the speed is controlled linearly
depending on the climatic conditions.
Basic ventilation only continues with DZMIN until
the desired humidity is reached or the absolute
humidity inside is lower than the absolute humidity
outside.
3.4.3. Cooling (K)
By simply adjusting the configuration parameters,
the device becomes a temperature-dependent
cooling control for factory and production halls,
server rooms and many other sensitive electrical
systems.
cooling with 1-stage fans
In cooling mode, natural ventilation starts when the
adjustable internal temperature limit (cooling TSP)
is exceeded. When the ventilation is switched on,
the temperature inside the room must be higher
than the temperature limit and the outside
temperature must be at least 2°C colder than the
inside temperature.
Control of cooling aggregates
In the case that Tinside > Cooling-TSP is given, but the
difference to the outside temperature Ta>Ti-2°C
does not apply, it is possible to operate a cooling
unit in combination with a single-stage or speed-
controlled fan at the second output of the climate
control.
Cooling with 2-stage fans
If 2-stage fans are connected, the second stage is
switched on if the following climatic conditions are
given:
Tinside > Toutside+5°C.

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Cooling with speed-controlled fans
When speed-controlled fans are used, the control is
carried out between the two adjustable limit values
DZMIN and DZMAX as a percentage value of the
control voltage (0-10VDC).
If the condition Tinside > Toutside+2° is given, the speed-
controlled fan is activated with the minimum speed
(DZMIN). If Tinside = Toutside+9°C the fan is operated at
full speed (DZMAX).
In between, the speed is controlled linearly
depending on the temperature conditions.
3.5. Comfort functions
Integrated time switch
With the integrated timer, active times for the
ventilation units can be set. In this way, the
ventilation remains switched on in the specified
time window regardless of the climatic conditions.
Frost protection
The frost protection function prevents the
monitored room from cooling down too much due
to ventilation when outside temperatures are close
to freezing point. For this purpose, a temperature is
set for the outside area at which the climate control
dispenses with ventilation cycles, even if the
climatic conditions would allow ventilation.
•Standard setting: 3°C
•Input range between 0-5°C in 1% steps
The frost protection function can be deactivated by
setting the value to 99.
Dry protection
Too dry room air disturbs the well-being. Dust and
other particles cannot be bound without sufficient
humidity.
The dry protection function ensures that the
humidity in the monitored room remains at a
healthy level for people and the building.
For this purpose, a desired humidity in the range
between 40% and 60% of the relative humidity can
be set in 5% steps in the control menu.
4. assembly and commissioning
The correct installation position is horizontal.
The device can be mounted on a wall in a few steps.
1: To install the unit and to connect the power cable
and the supply air and exhaust air elements, open
the housing cover panels (1) on the left and right
edge of the housing cover by folding them open.
2: Mark the 4 drill holes as provided.

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3: Mount the unit at a suitable place on the wall by
inserting the screws through the holes provided in
the housing and fastening the screws.
4: Remove the housing cover (2) after loosening the
4 screws.
5: Connect the power cable as well as the actuators
by passing the cables through the gland and
connecting them to the appropriate terminals. The
terminal blocks can be removed for this purpose.
Attention: For detailed
information on the electrical
connection of the actuators,
please refer to the section
"Actuator connection".
6: When all electrical cables are correctly
connected, place the housing cover (2) back onto
the lower part of the housing (3) and fasten it by
loosening the screws.

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7: Finally, close the housing cover panels (1) on the
left and right edges.
8: Connect the outdoor climate sensor to the
corresponding socket on the right side of the
bottom of the housing. If a remote indoor climate
sensor is included in the scope of delivery, repeat
the procedure for this sensor as well.
Avoid damage:
The climate sensor fits only one of
a certain position into the socket
provided. Make sure that you
insert the plug in the correct
position, otherwise the appliance
may malfunction and be
damaged.
ATTENTION
9: To complete commissioning, plug the power plug
into the power socket. The unit is then switched on.
5. connection of the actuators
The KST-20 Vento climate control system serves as
an intelligent mains switch and can also control
speed-controlled devices. Various connections are
available on the climate control system for this
purpose. Thus, several supply air and exhaust air
elements can be combined with each other and, if
necessary, supplemented by drying or cooling
devices.
The following typical devices can be connected
alternatively or in combination
•1-stage ventilation fans (230V AC)
•2-stage ventilation fans (230V AC)
•Speed controlled fans (0…10V DC)
•Motor driven window opener (230V AC)
•Ventilation flaps (up to 48V DC)
•Drying and cooling units (230V AC)
5.1. Control electronics
Danger to life:
Danger to life from electric shock.
Disconnecting the device from
the power supply.
DANGER
The KST-20 Vento has 5 terminal blocks (KL).

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Key to abbreviations:
KL 1: Power supply 230V AC
KL 2 and KL 3: 230 V Switching outputs
KL 4: 0…10 V Control outputs
KL 5: Potential-free output
Fi und Fa: Climate sensor connections
L, L1, L2 Phase
N Zero
PE Protective earth
PF1, PF2 Potential-free contact
0-10 0…10 V DC analogue output
GND Ground
Connector:
To use the potential-free output,
please use the supplied 2-pole
plug. The plug for terminal block 4
can only be used as an alternative
to terminal block 3. Replace if
necessary.
The supply air and return air
elements are switched with the
same unit logic, so that the
connections L1 and L2 of KL 2 and
KL 3 are connected in the unit.
5.2. Connection variants
The possible connection combinations that can be
used in the three different operating modes are
shown below. The detailed wiring diagrams can be
found at the end of this manual.
Dehumidify
Cooli
ng
Ventilation
1-stage fan for supply air
and exhaust air
-
1-stage fan and window
opener
- -
1-stage fan and
condensation dryer or
cooling unit
-
2-stage fans for supply air
and exhaust air
Speed-controlled fans for
supply air and exhaust air
Speed-controlled fans
and window openers
Speed-controlled fans
and condensation dryer /
cooling unit
-
– Unsupported connection variant
6. device functions
6.1. Factory settings
If the MODE button is pressed when the instrument
is switched on, the instrument changes to the
factory settings. The following values are set:
•Operating mode: Dehumidify
•Actuation: 1-stage fan
•Parameters are set to default settings
You can then set the respective duration for the
dehumidification operating mode, with which the
actuators remain switched on or off.
Use the "right arrow" button to skip this setting and
exit the factory settings menu.
With the ENTER key you change the menu level and
can change the settings one after the other for the
active time and passive time between 10 and 60
minutes.

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6.2. Display illumination
If no key is pressed on the control unit for longer
than 1 minute, the air conditioning control unit
automatically switches off the background lighting
of the display. Pressing any function key switches,
the display lighting back on.
6.3. Functions of the keys
All four operating keys on the device are basically
equipped with at least two functions. One is the
function which is illustrated on the key and the
other is the function described by the text below the
key.
Key „Trend “
In the dehumidifying mode, pressing the TREND key
resets the trend value, i.e. the current value for the
absolute humidity in the interior is stored as a
reference value for the subsequent
dehumidification success. This should be done after
the unit has been put into operation. The
dehumidification success can be checked later
during normal operation by pressing the PAUSE key.
If, however, the timer is active, it is deactivated by
pressing the TREND key.
Observe operating mode!
Tendency reset and deactivation of the
timer refer to the dehumidification
operating mode.
On the first level of the configuration menu,
pressing the TREND key takes you back to the menu
item „Start measurement".
Key „Mode “
In normal operation, a manual ventilation process
can be started by pressing the MODE button.
In the configuration menu, the MODE key can be
pressed to scroll to the left.
When the device is switched on, pressing the MODE
button takes you to the factory settings.
Key „Pause “
During normal operation, the automatic mode can
be interrupted with the PAUSE key. The display will
then show the stored reference value for absolute
humidity with the corresponding date and, on the
second line of the display, the current value for the
absolute humidity in the interior.
Key „Enter “
Press the ENTER key to open the configuration
menu and confirm the entries made within the
menu.
If the menu item "Start measurement" is confirmed
by pressing ENTER, the instrument exits the menu
and changes to the automatic mode.
6.4. Menu navigation and
configuration
The selected operating mode is indicated in the unit
display by the letters E for dehumidification, L for
ventilation and K for cooling.
In addition, the selected actuator system is
indicated at the end of the second line by the
corresponding character.

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•1= 1-stage fan
•2= 2-stage fan
•D= speed-controlled fan
•F= Window opener in combination with 1-
stage fan
•R= Window opener in combination with
speed-controlled fan
In the dehumidification operating mode, the values
for run through one after the other in normal
operation:
•Relative humidity indoor/outdoor (rHi, rHa)
•Temperature inside/outside (Ti, Ta)
•Absolute humidity inside/outside (aHi,aHa)
The unit is configured from normal operation by
pressing ENTER. The current climate control is
interrupted and the menu appears. The first line of
the display shows the relevant menu, while the
second line provides operating instructions.
The menu is structured from left to right. The MODE
and PAUSE keys are used to scroll through the
menu.
Faster operation:
In the first level of the menu, the
TREND key causes the menu to jump
to the item "Start measurement".
From here, the ENTER key can be
used to start normal operation.
6.4.1. operating mode
The selection of the desired operating mode is the
first setting to be made. Press the ENTER button to
open the setting. Then use the arrow keys (MODE,
PAUSE) to select between E (dehumidification), L
(ventilation according to DIN 1946) and K (cooling).
Press the ENTER key again to confirm the selection.
The menu is updated according to the operating
mode, so that some functions are activated or
hidden.
6.4.2. actuators
The connected actuators must be selected from the
menu in the same way as described above for the
operating mode.
The following options are available:
•1 = 1-speed fans (not in ventilation mode)
•2= 2-stage fans (for all operating modes)
•D = Speed-controlled fans (for all operating
modes)
•F = Window opener in combination with 1-
stage fan (only in dehumidifying mode)
•R= Window opener in combination with
speed-controlled fan
Connecting the devices:
The supply air and exhaust air
elements are switched with the
same unit logic, so that the
connections L1 and L2 of KL 2 and
KL 3 are connected in the unit.
The available connection
combinations can be found at the
end of the instructions.
Unit versions of two-stage fans:
Depending on the manufacturer
of the two-
stage fan to be
connected, settings must be
made in the menu:
In the menu "Actuators" first
select "2" and confirm the
selection with ENTER. Then press
the TREND button to enter the
selection for the type of two-
stage fan.
Select the appropriate
configuration according to the
circuit diagram of the fan.
Version 2-1
Connection
Version 2-2
Alternate switching

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6.4.3. antifreeze temperature (FS)
This option is only available in the dehumidification
mode.
The anti-freeze temperature setting ensures that
ventilation does not take place if the outside
temperature is too low. The setting range is 0°C-5°C.
The default setting is 3°C.
6.4.4. Timer (Suhr)
This option is only available in the dehumidification
mode.
If 00:00 is entered in the menu for both the switch-
on and the switch-off time, the time switch function
is switched off.
Otherwise, ventilation will run in the specified time
range with the appropriate actuators without taking
the actual climate values into account.
The setting is made according to the following
scheme:
•Enter the switch-on time [hh] ENTER [mm]
ENTER
•Entering the switch-off time [hh] ENTER
[mm] ENTER
During normal operation, a running timer function
can be switched off using the TREND key.
6.4.5. dry protection (TS)
This option is only available in the dehumidification
mode.
The dry protection function ensures that the
relative humidity in the corresponding room is not
too low.
The input range is between 30% and 40% of relative
humidity.
6.4.6. Time
This option is available in all operating modes.
The input of the current time is especially important
for the timer. After setting the time for the first
time, the time is retained and continues to count
automatically.
Continuously pressing the PAUSE key will cause the
numbers to scroll faster.
6.4.7. Date
This option is available in all operating modes.
After the first setting, the date is retained and
continues to count independently. Continuously
pressing the PAUSE key will cause the numbers to
scroll faster.
6.4.8. target moisture
This option is only available in the ventilation
operating mode.
The target humidity describes a desired humidity
level in the room concerned, which must be
maintained by the climate control system.
The input range is between 40% and 60% and can
be set in 5% relative humidity steps.
6.4.9. Delta aH
This option is not available in cooling mode.
This setting is only activated if 2-stage ventilation
units are connected.
The setting refers to the switching threshold for the
second ventilation stage.
The input range is between 5 and 10 g/m³.

Climate Controller KST-20 Vento | KST-20 Vento/CO2 | KST-20 Vento/RN
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6.4.10. Cool -TSP
This option is only available in cooling mode.
The device parameter Temperature switching
threshold for cooling defines the switching
threshold for the cooling operating mode.
The input range is between 24°C and 30°C for the
indoor temperature.
6.4.11.Speed Min/Max
This option is available in all operating modes if
speed-controlled fans are connected and selected
in the actuators.
The input range of the lower speed threshold is 10%
to 30% from 0-10VDC and can be adjusted in 5%
steps.
The input range of the upper speed threshold is 70%
to 90% from 0-10VDC and can be adjusted in 5%
steps.
6.4.12.LEDs
Mode LED
•On: Normal operation
•Flashing: manual mode
Status LED
•On: actuators on
•Off: actuators off
6.4.13.Error indication on the display
•Error indoor sensor
•Error external sensor
•System Error XX
ATTENTION:
If the error messages appear,
please contact ZILA Support.
7. circuit diagrams
Two 1-stage fans
1-stage fans & Window opener (F)

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1-stage fan and Condensation dryer
two speed-controlled fans
two 2-stage fans
1 speed-controlled fan and 1 Condensation dryer

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Handbook Version: ENG_05052020_ANHU_KST20VENTO| 18
1 speed-controlled fan und 1 window opener
8. additions to the KST-20
Vento/CO2
The monitoring of CO2 and the climate values only
takes place in the operating mode "ventilation".
8.1. actuators
2-stage or speed-controlled fans can be used as
actuators.
If 2-stage fans are connected, the control is
regulated like:
•Stage 1 (basic ventilation) as soon as the unit
is switched on
•Stage 2, if CO2 limit value is exceeded or at
absolute humidity outside less than inside
With speed-controlled fans, the fan runs at the set
minimum speed DZMIN until the CO2 limit value is
reached. The speed increases linearly up to the set
maximum speed DZMAX depending on the CO2
value. The upper limit for CO2 is set at 3000 ppm.
The speed also changes climate-controlled,
whereby CO2 has priority.
8.2. CO2- Measurement
The device also has a CO2 sensor for monitoring the
air quality.
If the CO2 concentration in the room is below the
set limit value, there is no control according to CO2,
i.e. climate control is carried out (aH controlled).
As soon as the CO2 limit is exceeded, the respective
control outputs are activated regardless of the
climate values.
The current CO2 measured value can be displayed
at any time using the PAUSE key (note: the control
outputs also switch off in this case)
8.3. Connection of the sensors
The KST-20 Vento/CO2 is equipped with three
connection sockets for the sensors. The indoor
climate sensor is connected to the upper left beech.
The outdoor climate sensor is connected to the
upper right socket. The lower, central socket is
intended for connecting the CO2 sensor.
Indoor Climate Sensor
Outdoor Climate Sensor
CO2 Sensor

Climate Controller KST-20 Vento | KST-20 Vento/CO2 | KST-20 Vento/RN
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9. additions to the KST-20
Vento /RN
The monitoring of radon and the climate values only
takes place in the operating mode
"dehumidification".
9.1. actuators
1-stage, 2-stage or speed-controlled fans, window
openers as well as heating registers in combination
with speed-controlled fans can be used as
actuators.
If 2-stage fans are connected, the control is
regulated like:
•Stage 1 as soon as the limit value is exceeded.
•Step 2, if the value is 50 % above the set limit
value
With speed-controlled fans, the fan starts at the set
minimum speed DZMIN when the Radon limit value
is reached. The speed increases linearly up to the
set maximum speed DZMAX. DZMAX is reached
when the Radon value is 50% above the set Radon
limit value.
9.2. Radon measurement
The device has an additional radon sensor for
monitoring the radon concentration.
If the radon concentration in the room is below the
set limit value, there is no regulation according to
radon, i.e. the regulation is climate controlled (aH
controlled).
As soon as the radon limit is exceeded, the
respective control outputs are activated regardless
of the climate values. The current Radon value is
shown on the display.
9.3. Connection of the sensors
The KST-20 Vento/RN is equipped with three
connection sockets for the sensors. The indoor
climate sensor is connected to the upper left beech.
The outdoor climate sensor is connected to the
upper right socket. The radon sensor is connected
to the lower middle socket.
In case of a Radon sensor error, the display shows
"Sensor error". The climate control system then
continues to ventilate at the set interval.
Indoor Climate Sensor
Outdoor Climate Sensor
Radon Sensor

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10. device support
Phone: [phone]
E-Mail: [email protected]
Manufacturer of the device
ZILA GmbH
Neuer Friedberg 5
98527 Suhl
Phone: [phone]
Fax: [phone]
Web: www.zila.de
e-Mail: [e-mail]