Thank you that you have chosen the G-Systems Engineering Ltd CO₂ Controller product.

The CO₂ ventilation controller is a multifunctional device designed to manage climate and air quality in ventilated rooms. It offers the following key features:

• Fan speed control  for ventilated rooms, allowing regulation of an exhaust fan or both intake and exhaust fans, as well as controlled dosing of CO₂ gas.

• Lighting control , including on/off switching and continuous dimming of connected lighting systems.

• Programmable sockets  that can be controlled based on sensor values or timers, for example for heating, cooling, humidification, dehumidification, or operation of a CO₂ valve.

The primary purpose of the CO₂ Controller is to maintain optimal room temperature and humidity levels, both during the day and at night, with independent target values for each period. In addition, the controller creates a slight negative pressure in the room to prevent odors from escaping into surrounding areas.

The warranty is valid only if:

• A warranty card issued by the seller with stamp, signature, and sales date is included,  or

• A purchase receipt or invoice with the printed serial number is available,  or

• An electronic registration has been made at http://g-systems.eu/warranty/

If none of these documents are available, please contact your point of sale.

Operating voltage:  230V / 50Hz

Maximum permissible plug and cable ratings, country-dependent:

• Type F (Schuko, DE):  max. 16A

• Type E (FR):  max. 16A

• Type J (CH):  max. 13A

• Type G (UK):  max. 13A

Output load capacities, resistive load, cos φ = 1:

• Output 1 (variable):  min. 200W / max. 10A (2300W)

• Output 2 (variable):  min. 200W / max. 10A (2300W)

• Output 3:  max. 10A (2300W)

• Output 4:  max. 10A (2300W)

Each pair of outputs shares a common 16A supply line:
Outputs 1 and 3  are supplied via one 16A input, and  Outputs 2 and 4  are supplied via a second 16A input.
The  combined load  of each output pair must  not exceed 16A .

Control signal outputs:

• Intake fan:  0–10V or PWM

• Exhaust fan:  0–10V or PWM

• Light control:  0–10V

Install the device using the supplied mounting bracket on a solid, non-combustible surface (e.g., concrete or masonry).
Installation on combustible materials, including wood, plastic, cardboard, or similar, is not permitted.

Ensure that the installation location provides adequate ventilation to allow effective dissipation of heat generated during operation.
Do not install the device in confined spaces, enclosed cabinets, or areas with insufficient air circulation.

⚠️ Warning:
Improper installation or insufficient ventilation may cause overheating, resulting in malfunction, damage to the device, or risk of fire.

You can navigate through the menu using the  rotary push knob :

• Turn clockwise to move to the next option or to increase a setpoint.

• Turn counterclockwise to decrease a setpoint.

• Press the knob to confirm a selection or to save a value.

This menu allows you to configure the parameters for room ventilation:

1. Ventilation Menu –  Main overview

2. Temperature Settings  – Configure ventilation based on temperature thresholds

3. Humidity Settings  – Configure ventilation based on humidity thresholds

4. Minimum and Maximum Fan Speeds – Set the operational range of the fan

5. Negative Pressure Setting  – Maintain a slight negative-pressure for odor or air control

Note:

These settings are only active during the  daytime when  CO₂ dosing is deactivated  or the  “CO₂ bottle empty”  alarm is triggered.
During  nighttime operation , ventilation is always regulated according to these settings.

In this menu, you can define the desired daytime and nighttime temperature setpoints, as well as the temperature hysteresis range.

1. Temperature Settings – Overview of this menu

2. Day Temperature  – Target temperature during daytime operation

3. Night Temperature  – Target temperature during nighttime operation

4. Temperature Hysteresis  – Range used for smooth fan speed modulation

Adjustment Guide

Set the desired  day and night temperatures here, along with the  positive hysteresis  value.

Example:

If the  day temperature  is set to 24.0 °C  and the  hysteresis  is +2.0 °C :

• Up to  24.0 °C , the fans remain off or operate at  minimum speed

• Between  24.0 °C and 26.0 °C , fan speed  increases linearly

• At  26.0 °C and above , fans operate at the  maximum configured speed

In this menu, you can define the desired humidity setpoints for daytime and nighttime operation, as well as the hysteresis range for smooth fan control.

1. Humidity Settings – Overview

2. Daytime Humidity – Target relative humidity during the day

3. Nighttime Humidity – Target relative humidity at night

4. Humidity Hysteresis – Tolerance range for gradual fan speed adjustment

Adjustment Notes

Set the desired  daytime and nighttime relative humidity  values along with the  positive hysteresis .

Example:

If the target is  60% RH (Relative Humidity)  and the hysteresis is set to  +10% RH :

• Up to  60% RH : Fans remain off  or run at  minimum speed

• Between  60% and 70% RH : Fan speed  increases gradually

• From  70% RH and above : Fans operate at  maximum speed

Important:

The  higher deviation  — whether from the  temperature  or  humidity setpoint — determines the fan speed.

In this menu, you define the limits for fan speeds that must not be exceeded or undercut – separately for daytime and nighttime operation.

1. Max. & Min. Fan Speeds – Overview

2. Minimum Fan Speed (Day)

3. Minimum Fan Speed (Night)

4. Maximum Fan Speed (Day)

5. Maximum Fan Speed (Night)

6. Intake Fan Behavior – Off or set to minimum

7. Exhaust Fan Cut-Off Temperature

Explanation:

Settings 2–5 define the  permitted range of fan speeds based on time of day.
Each value sets the  operating window  for speed modulation.

When both  temperature and humidity are below  their setpoints, this setting controls how the  intake fan  responds:

• Off  – Intake fan is completely shut off

• On  – Intake fan runs at the  exhaust fan’s speed minus the defined pressure differential

If the  room temperature  drops below this value, the  exhaust fan  is automatically switched off to prevent the room from overcooling.

In this menu, you can define the pressure difference between the intake and exhaust fans to maintain a constant negative pressure inside the room.

1. Negative Pressure Menu – Overview

2. Negative Pressure Setting  – Pressure difference in percent (%)

Purpose

To prevent  unwanted odors  from escaping the room, the  exhaust fan  must extract  more air  than the intake fan supplies.
This creates a slight negative pressure , ensuring that potentially contaminated air stays inside.

Practical Setup Tip

• Run both intake and exhaust fans at  maximum speed .

• Check airflow behavior, e.g., by observing air movement through a  keyhole  or  door gap :

  • Air should be  drawn into the room — not pushed out.

• Adjust the  negative pressure setting until there’s a  slight inward draft , but  not so strong  that it makes the door hard to open.

To configure the lighting settings, return to the main menu and select: ➡️ 5. Lighting Settings

Main Menu → Lighting Settings

1. Lighting Settings Menu – Overview

2. Enable/Disable Lighting – Turn the lighting function on or off

3. Lighting Schedule – Define on/off times

4. Maximum and Minimum Brightness – Set brightness limits

5. Sunrise and Sunset Simulation – Enable soft transitions in light intensity

Installation Note

Lighting is controlled via a  signal output and should be connected to your lighting system using the port labeled  “Light.”

Adapters & Accessories

A range of  adapter cables and connectors is available at:  www.growshopping.com or from your local distributor.

Lighting Connection

To connect the lighting system, the following  pins are required:

• Pin 2:  GND (Ground)

• Pin 4:  Signal (Control signal output)

1. Lighting Schedule Menu – Overview

2. Lighting ON Time  – Set the switch-on time

3. Lighting OFF Time  – Set the switch-off time

Note:

Set the lighting  start and end times in  hours and minutes .

1. Light Intensity Menu – Overview

2. Start CO₂ Time – Temperature (for reference only)

3. Stop CO₂ Time / Start Exhaust – Temperature (for reference only)

4. Start Dimming Temperature  – Temperature at which dimming begins

5. Stop Dimming Temperature  – Temperature at which dimming ends

6. Maximum Light Intensity

7. Minimum Light Intensity

8. Lighting Re-Enable Temperature

9. Lighting Cut-Off Temperature

Function Description:

• Items 2 and 3  (marked red in the UI) are  for reference only .

• Start Dimming Temperature (4):
  This is the point where lamps begin to  dim  in response to increasing heat.
  → As long as the measured temperature remains  below this value , lamps operate at  maximum intensity (6) .

• Stop Dimming Temperature (5):
  The point at which dimming ends. Once this temperature is reached, the system sets the  minimum light intensity (7) .

• The  minimum intensity remains active  until the room reaches the lighting cut-off temperature (9) .

• If the temperature continues to rise and overheating persists , the system fully  switches off the lights  at the cut-off point (9).

• Lights will only turn back on once the temperature falls  below the re-enable temperature (8) .

Adjustment Note:

Set the  minimum light intensity (Option 7) to a level where the lamps  continue operating reliably even at the lowest dimming level .
→ They should  not turn off completely , unless this behavior is  explicitly intended .

This menu allows you to activate and configure soft dimming for sunrise and sunset transitions.

1. Sunrise & Sunset Menu – Overview

2. Sunrise Duration  – Duration in minutes

3. Sunset Duration  – Duration in minutes

4. Enable Sunrise Simulation

5. Enable Sunset Simulation

Example – Sunrise (10 minutes):

• At the  lighting ON time , the system starts the  sunrise simulation .

• The lights begin at the  minimum intensity .

• Over the next  10 minutes , the brightness gradually  ramps up  to the  maximum intensity .

Example – Sunset (10 minutes):

• 10 minutes before the lighting OFF time , the  sunset simulation  begins.

• The brightness dims smoothly from the current level down to the  minimum intensity .

• After the countdown, lighting is fully dimmed.

To configure the switching logic for Output 1, return to the main menu and select: 6. Output 1 – Settings

1. Output 1 – Menu

2. Intake Fan (AC)

3. Exhaust Fan (AC)

4. Manual Switching

5. CO₂ / Temperature / Humidity / Light Sensor  (Gas Sensor)

6. Temperature Sensor

7. Timer (Time Switch)

8. CO₂ Solenoid Valve

You are now configuring Exit 1

This output can operate in one of the following two modes:

• Variable Control
  via phase-angle control  (only suitable for  AC fans ) → options  2–3

• Relay-based ON/OFF switching
  for all other devices → options  4–8

The currently active function is visually indicated with a  green frame  around its icon in the menu.

• Connect a  minimum load of 200 W to ensure stable operation.

• Ensure that the fans  truly stop at 0% .
  → Some small fans with large suppression coils may continue spinning even when set to 0%.

How to Activate a Function:

1. Select the desired function (e.g. fan, sensor, relay).

2. Activate it using the toggle switch.

3. Only  one function per output can be active at a time.

• Enable this mode to control the output manually.

• Use the provided  toggle  to switch the output  ON or OFF .

• (Note: No graphical representation is available for this mode.)

1. Gas Sensor Menu – Overview

2. Enable/Disable Sensor  – Turn the sensor module on or off

3. Heating  – Activate output when temperature is too low

4. Cooling  – Activate output when temperature is too high

5. Humidifying  – Activate output when humidity is too low

6. Dehumidifying  – Activate output when humidity is too high

Usage Instructions:

1. Activate the sensor  using option 2.

2. Then  select one of the four control functions :

   • Heating  (3)

   • Cooling  (4)

   • Humidifying  (5)

   • Dehumidifying  (6)

Each function uses the sensor’s readings to control the output relay accordingly.

1. Heating Menu – Overview

2. Enable/Disable Heating  – Turn the heating output ON or OFF

3. Daytime Temperature  – Set target temperature for daytime

4. Nighttime Temperature  – Set target temperature for nighttime

5. Temperature Hysteresis  – Define the switching buffer range (negative value for heating)

Configuration:

Set a  target temperature  for both day and night , along with a  negative hysteresis  value.

Example – Heating:

• Target Temperature:  24.0 °C

• Hysteresis:  –2.0 °C
  ➡ Heating turns  ON at <22.0 °C
  ➡ Heating turns OFF at >24.0 °C

• Select the  temperature sensor to be used.

Configuration:

The settings and behavior are  identical to the gas sensor  when used with the  “Heating” function.

→ See the  Heating  section for configuration instructions regarding:

• Day/Night target temperatures

• Negative hysteresis

• On/off switching behavior based on measured temperature

1. Timer Menu – Overview

2. Enable/Disable Timer

3. Step(s) – Program step number (up to 24 steps)

4. Start Time (Hours/Minutes)

5. End Time (Hours/Minutes)

6. End Time (Seconds)

7. Enable/Disable Step

How to Use the Timer:

1. Enable the timer function via option 2.

2. Use the rotary knob to scroll through up to 24 programmable steps .
   ➤ The  currently selected step  is indicated by  two bars  on the left and right.

3. Press the knob to enter edit mode and set the time:

   • →  Start Hour

   • →  Start Minute

   • →  End Hour

   • →  End Minute

   • →  End Second

4. Enable the step  once it’s configured, then move to the next step if needed.

If you want to use the  CO₂ solenoid valve  on this output, select this function and  enable it using the toggle switch .

Outputs 3 and 4 operate based on the same principle as Outputs 1 and 2, with the following key differences:

• ❌  No variable control  (no phase-angle regulation)

• ✅  Relay switching only (ON/OFF control)

In this submenu, you can configure all  core system parameters  of the device, such as time, backlight, alarm behavior, and sensor offset.

1. Device Settings Menu – Overview

2. Time and Date – Set system clock and calendar

3. Light Sensor – Automatic brightness adjustment via ambient light

4. Screen (Display) – Adjust brightness, contrast, and screen timeout

5. Alarms – Enable/disable alarms, set volume and alert behavior

6. Sensor Signal Offset – Fine-tune sensor readings

7. Output Signals – Configure output signal behavior

8. Reset to Factory Settings – Restore all settings to default state

9. Reset Min/Max Values – Clear all stored extreme measurement values

1. Time and Date Menu – Overview

2. Date – Set in the order: Day → Month → Year

3. Time – Set in: Hours → Minutes

4. Day Counter – Tracks usage days

Explanations:

• Date:
  Set the current date using the sequence:  Day → Month → Year

• Time:
  Enter the current time in  hours and minutes

• Day Counter:

  • On the first day of use, the counter starts at  1

  • It  automatically increases by +1 at 23:59:59  each day

  • ⚠️  Important:
    If the device is  powered off at that time , the counter will not increment

In this menu, you configure the light intensity detection feature of the gas sensor to allow automatic switching between day and night modes.

1. Light Sensor Menu  – Overview

2. Light Intensity  – Currently measured brightness (in %)

3. Switch Delay  – Delay time before switching occurs

4. Switch Threshold  – Light intensity level at which the system switches modes

How It Works

1. First , turn on your lighting at the  minimum intensity setting .

2. The  Light Intensity  value will show the current brightness detected by the gas sensor.

   • Ideally, when lighting is on, this value should be close to  100% , which the controller automatically interprets as  “Day Mode.”

Switch Delay:

This setting prevents  immediate switching when there is a  brief change in lighting  (e.g., when the door opens).

• When the  switch threshold  is exceeded, the  switch timer  starts.

• Only if the brightness  remains stable for the entire delay period, the system switches between  Day and  Night  modes.

Switch Threshold:

Here you define the  light intensity level (in %)  that triggers the transition between  Day Mode and  Night Mode .

In this menu, you can configure the display behavior of the device.

1. Display Menu  – Overview

2. On / Automatic  – Display operating mode

3. Timeout Duration  – Time before automatic screen shutdown

4. Brightness  – Adjust screen brightness

Recommendation:

To  prolong the display’s lifespan , it is recommended to set the screen to  “Automatic” mode when not in use.

How Automatic Mode Works:

• In  Option 3: Timeout Duration , you define how long the display stays on  without user interaction .

• After the set time passes:

  • The display  dims for 10 seconds

  • Then it  turns off completely

➡️ To  wake up the screen , simply  rotate or press  the control knob.

Brightness:

• Under  Option 4 , set the screen brightness according to your  ambient lighting conditions  or  personal preference .

In this menu, you can define  which sensor values will trigger alarms .

1. Alarms Menu – Overview

2. Temperature (Gas Sensor)

3. Humidity (Gas Sensor)

4. CO₂ (Gas Sensor)

5. Temperature Sensor (External Sensor)

How to Set Alarms:

1. Select the sensor parameter you wish to monitor
   → e.g.  "Temperature (Gas Sensor)"

2. In the corresponding  submenu , you can configure:

   • Threshold values (upper/lower limits)

   • Hysteresis  (optional)

   • Alarm behavior  (e.g., acoustic, visual, both)

Important Note:

Alarms are crucial for identifying  critical conditions early , such as:

• Overheating

• Excessive CO₂ concentration

• Humidity levels outside the safe range

1. Temperature (Gas Sensor) – Menu Overview

2. Maximum Temperature – Threshold for overtemperature alarm

3. Enable/Disable Maximum Temperature Alarm

4. Minimum Temperature – Threshold for undertemperature alarm

5. Enable/Disable Minimum Temperature Alarm

Procedure – Setting Up Temperature Alarms 

• Set the desired threshold value at which you want to be alerted.
  →  Example: 2. Maximum Temperature = 35.0 °C

• Enable the alarm  function under  Option 3 .

What Happens When an Alarm Is Triggered?

• If the measured value  exceeds or falls below  the set limit, a  red alarm screen will appear on the device.

• If  Wi-Fi is enabled  and you are using the  GSE smartphone app , a  push notification  will be sent to your phone.

Repeat the same steps for:

• 4. Minimum Temperature  – e.g., for  frost protection

• 3. Humidity (Gas Sensor)

• 4. CO₂ (Gas Sensor)

• 5. External Temperature Sensor

In this menu, you can manually correct displayed sensor readings by adjusting the values shown on the screen.

1. Offset Menu – Overview

2. Temperature Offset (Gas Sensor)

3. Humidity Offset (Gas Sensor)

4. CO₂ Offset (Gas Sensor)

5. Temperature Offset (External Sensor)

How to Use:

If the values shown on the screen  differ from a reference device , you can enter a  positive or negative offset  here to match the display to your reference.

Important Note:

This function does  not perform an actual calibration  of the sensor.
It only adjusts the  displayed value  – the internal measurement logic and sensor readings remain unchanged.

Example:

• Your reference thermometer shows:  22.5 °C

• The display shows:  21.5 °C
  ➡ Enter a  +1.0 °C offset  under  Temperature Offset

In this menu, you configure the signal output types and minimum speeds for EC fans as well as the lighting control output .

1. Output Signal Menu – Overview

2. EC Intake Fan – Signal Type

3. EC Intake Fan – Minimum Speed

4. EC Exhaust Fan – Signal Type

5. EC Exhaust Fan – Minimum Speed

6. Lighting – Signal Type

Configuring the EC Intake Fan

1. In  Option 2 , select the desired  signal type :

   • 0–10 V (analog)  or

   • PWM (pulse-width modulation)

2. Go to the  Ventilation → Min/Max Speeds  menu and set the  maximum speed  of the intake fan to  1% .

3. Check on the  main screen (Section 2) whether the 1% value is actually applied.

Test Run:

• Observe whether the EC intake fan starts spinning at  1%  speed.

• If the fan does not rotate or just shakes slightly, increase
  Option 3 – EC Intake Fan Minimum Speed  by  +1% .

Repeat this process until the fan  reliably starts spinning on its own  when switched on.

Configuring the EC Exhaust Fan

Repeat the same procedure for:

• Option 4 – EC Exhaust Fan Signal Type

• Option 5 – EC Exhaust Fan Minimum Speed

Tip:

Some EC fans require a  higher minimum speed  to run stably.
→ Depending on the model, this is usually between  5% and 15% .

Configure Lighting Signal

To configure the lighting control output:

• Go to  Option 6: Lighting – Signal Type

• Select the desired output type:

  • 0–10 V (analog)

  • or  PWM (pulse-width modulation)

1. Factory Reset Menu – Overview

2. Select Reset Option: YES / NO

3. Current software Version installed

Procedure:

1. Select  "YES"  to initiate the reset process.

2. A  black confirmation screen will appear with a  second safety prompt .

3. Confirm the reset by selecting the  green checkmark symbol   ✅ or cancel by selecting the  red cross symbol ❌

The controller will then  restart , and all data will be reset to factory defaults.

Warning:

This action  cannot be undone .
All personal settings, timers, sensor values, and calibrations will be permanently deleted .

Procedure:

Follow the  same steps  as for the “Reset to Factory Settings”  function:

1. Navigate to this menu

2. Select  “YES”  to confirm

3. A confirmation prompt will appear

4. Confirm the reset by selecting the  green checkmark symbol   ✅ or cancel by selecting the  red cross symbol ❌

Once confirmed, all recorded  extreme values  will be deleted.
→ The controller will automatically  begin recording new min/max values from that point onward.