CO2 Indicator - SCHOOL
€231.09
The Schabus “School”: the CO₂ traffic light for good air and a healthy learning climate at school, clearly visible, without flashing light and alarm tone
The CO₂ traffic light “School” was specially developed for use in classrooms, training rooms and educational institutions. With its clearly visible 3-colour signalling, it provides clear orientation in everyday teaching and reliably reminds users to ventilate in good time. Unlike the compact plug-in traffic light, the “School” is deliberately designed as a clearly visible signal light, ideal also for larger rooms.
An internal infrared sensor (NDIR) continuously measures the carbon dioxide (CO₂) in the room air. CO₂ serves as a reliable indicator of stale air and increasing aerosol load. The traffic light switches precisely to yellow when it is time to ventilate, and back to green in good time when the air is fresh. In this way, ventilation is neither too early nor too late and neither too short nor too long – which also saves heating and air-conditioning costs as a side effect.
Important note: The “School” is not a calibrated measuring instrument, but a visual system for assessing indoor air quality. In addition: please do not unplug the traffic light overnight. It needs the night-time rest periods in order to calibrate correctly.
Good to know: The “School” reminds users to ventilate; it does not replace the proper installation, use and maintenance of supply and exhaust air systems and their air-conditioning controls. It is supplied without flashing light, without alarm tone and without sensor button for uninterrupted teaching.
Fresh air without freezing: ventilate and save energy at the same time
Clearly visible 3-colour traffic light
Green, yellow and red are clearly recognisable from anywhere in the room, for teachers as well as for pupils.
Special School threshold values
Yellow from 1,000 ppm, red from 2,000 ppm, without an additional flashing stage. The values are based on hygiene recommendations for school operation and promote regular, energy-efficient ventilation.
Precise NDIR measuring technology
The integrated infrared sensor continuously measures the CO₂ concentration of the room air.
Uninterrupted teaching
Supplied without flashing light and without alarm tone; the traffic light signals calmly and clearly.
Automatic night dimming
A light sensor dims the LEDs after approx. 10 minutes in complete darkness and thus reduces energy consumption.
Auto-calibration
The traffic light automatically aligns itself to its theoretical zero point on a weekly cycle. This has been deliberately optimised for everyday school life.
Long-life LEDs
Particularly low energy costs thanks to long-life LED lights.
Simple wall mounting
Wall bracket and plug-in power supply unit; mounting material is included.
Housing colours
Standard green, on request white or grey; further RAL colours on request.
Meets many funding guidelines
The manufacturer cites the switching thresholds as the basis of the RKI recommendation for classrooms, so that the “School” meets many funding guidelines of the German federal states.
What is included in the box
The “School” has no options and no additional variants. Everything you need for wall mounting and operation is included. Accessories can be ordered separately if required.
- CO₂ traffic light “School” with permanently connected supply cable
- Wall bracket
- Plug-in power supply unit
- Mounting material (4 screws and wall plugs) and Allen key
- Detailed German operating instructions
How the “School” is designed
The “School” is a slim signal column with three light stages, a sensor area and a wall bracket. The housing must not be opened; it contains no parts that you need to maintain.
Three light stages: red, yellow, green
At the top is the red stage, in the middle the yellow and at the bottom the green. On the “School” each stage lights continuously; there is no flashing stage for red.
CO₂ and light sensor behind the protective grille
Behind the protective grille on the housing are the internal NDIR infrared sensor for CO₂ and the light sensor for night dimming. The grille must remain free so that room air can reach the sensor.
Cover screw for the anti-theft device
At the top of the housing is a screw. If you use the optional anti-theft device, the steel cable is firmly connected to the traffic light in place of this cover screw using the supplied screw.
Wall bracket with Allen screws
The wall bracket is fixed to the wall with the supplied screws and wall plugs. Allen screws are fitted on the bracket; the matching Allen key is included.
Supply cable and plug-in power supply unit
The supply cable is led out at the bottom of the wall bracket and is connected to the supplied plug-in power supply unit, which you plug into a socket. If the distance to the socket is greater, an extension cable helps.
No operating elements
The “School” is supplied without a sensor button. This means there is nothing to operate during lessons and nothing that can be accidentally adjusted. You test the function of all LEDs by switching the operating voltage off and on again.
What the colours mean
Green: air is OK
The CO₂ concentration is below the first threshold value. Close the windows as soon as green is reached.
Yellow: time to ventilate
From 1,000 ppm yellow lights. Open a window and ventilate until the traffic light lights green again. Get into the habit of ventilating already at yellow.
Red: ventilate thoroughly now
From 2,000 ppm red lights, without flashing and without alarm tone. No panic: the thresholds are set so low that there is still no danger to life for a long time. However, the room must be thoroughly ventilated by this point at the latest.
Yellow flashing: fault
There are faults that the traffic light can detect itself. It then flashes yellow. Information on remedying them can be found under “Troubleshooting”.
Start: green flashing
When plugged in, each colour first lights up once; then green flashes during initialisation.
Correct installation and connection
The traffic light may only be installed in dry indoor rooms in which there are no technical installations with carbon dioxide under pressure. It should be clearly visible from as many places in the room as possible.
Installation
- Choose the position: Mount the wall bracket as far as possible from the nearest window or door at a height of approx. 1.8 to 2.0 m. The higher the traffic light hangs, the less sensitive it becomes. Maintain a minimum distance of 30 cm from all corners, edges and the ceiling.
- Mark the drill holes: The fixing holes do not have the same spacing vertically as horizontally. Mark them beforehand for this reason.
- Fix the wall bracket: Screw the bracket to the wall with the supplied screws and wall plugs.
- Insert the traffic light: Place the traffic light in the bracket, using the supplied Allen key if necessary.
- Ensure a free position: Choose a place where the traffic light does not get in the way and where things are not regularly hung or attached.
Connection
- Plug-in power supply unit: Plug into a socket and connect to the supply cable of the traffic light that is led out at the bottom of the wall bracket
- Extension cable: For high mounting positions or a distant socket, a DC extension cable from the power supply unit to the traffic light is possible; for cable extensions observe the operating instructions
- Continuous operation: Leave the traffic light connected to the mains, also overnight; only in the event of operational interruptions of more than one week may it be unplugged
Where the traffic light must not hang
- In places that could prevent an alarm from being triggered, for example behind curtains or in cupboards
- Directly above a cooker, a combustion appliance or a sink
- Directly next to a door, a window, a ventilation opening, a fan or an air-conditioning unit
- In areas where dust, moisture or dirt can put the sensor out of operation; moisture must be kept completely away
- In potentially explosive atmospheres
Start, calibrate, test and care
Commissioning
- Ventilate the room thoroughly: This creates clean starting conditions.
- Connect the power supply unit: Plug the plug-in power supply unit into the socket and connect it to the supply cable of the traffic light.
- Wait for the start phase: First each colour lights up once. After around three minutes the traffic light is ready for operation; until then it flashes green.
- Keep your distance: Move away from the traffic light during this time so that your breath does not falsify the starting conditions.
Auto-calibration and night operation
For permanently precise CO₂ measurement the traffic light should remain continuously connected to the mains, also overnight. During the night-time rest periods the device uses the lowest measured CO₂ values for automatic self-calibration. The traffic light remembers the lowest CO₂ concentration of the last 7 days and aligns itself to its theoretical zero point on this weekly cycle. The 7-day period was deliberately chosen because the average of the weeks is more similar than the average of individual days. If the traffic light is regularly unplugged overnight, calibration cannot take place correctly.
In complete darkness the green LEDs are strongly dimmed after approx. 10 minutes in order to save energy. In brightness or when CO₂ values rise to the yellow stage the LEDs switch back to full brightness immediately. The sensor remains active even in darkness; the traffic light remains ready for operation and calibrates itself independently in the background.
Functional test
- Test once a month: The manufacturer recommends this test monthly for your safety.
- Use exhaled air: Take a deep breath and, when exhaling, blow gently with pursed lips in the direction of the grille of the traffic light from a distance of about 30 to 50 cm.
- Wait for the reaction: Give the traffic light up to 60 seconds. Exhaled air contains a great deal of CO₂; such a rapid increase is not normal for rooms; the traffic light detects it and jumps to red.
- Observe the decrease: Move a few metres away and watch how the stages go from red via yellow back to green.
- Check the LEDs: You test the function of all LEDs by switching the operating voltage off and on again.
Cleaning and care
- Remove dust from the sensor regularly by gently blowing it away
- Do not use compressed-air devices for this purpose
- Keep moisture and humidity away from the sensor
- The service life of the sensor increases significantly if the traffic light operates in a regularly well-ventilated room; 30 minutes of fresh air per operating day is a desirable optimum
- Do not open the device; it contains no parts that you need to maintain
Troubleshooting
- Yellow flashing (fault)? Unplug the traffic light, wait approx. 5 minutes and put it back into operation
- Fault remains? Take the traffic light into the fresh air and operate it there again for approx. 30 minutes
- Fault still present? Contact the manufacturer so that the traffic light can be repaired or replaced
- Unexpected values? Check whether the traffic light was unplugged overnight, whether the sensor grille is covered or dirty, and whether the location is next to a window, door or ventilation opening
Useful accessories, available separately
The accessories are not included in the scope of delivery and are ordered extra if required.
Ball protection grille, Art. No. 300947
Robust protective grille made of galvanised steel wire for classrooms, gymnasiums and sports facilities, but also kindergartens. It protects against hard impacts from balls or flying toys without impairing air circulation or measuring accuracy. Mounting material is included.
Anti-theft device, Art. No. 300948
For publicly accessible rooms such as corridors, waiting areas or seminar rooms. The coated steel cable is screwed into the wall and makes opportunistic removal considerably more difficult. Mounting material is included.
Metal stand, Art. No. 400110
For table or floor mounting with milled aluminium tube for lateral cable entry. It is fixed in place and ensures good visibility even in spacious rooms.
Extension cable
DC extension cable from the power supply unit to the traffic light, available in 1.5 m, 3 m, 6 m and 10 m; special lengths on request. Useful for high mounting positions, large rooms and distant sockets.
Fresh air: why CO₂ is a good indicator
Fresh air means more well-being and more performance. Too little oxygen makes you listless and tired and ultimately more susceptible to illness. Nobody wants to freeze either, so the right amount of ventilation needs to be found. Often ventilation is too short, too long or too frequent, which causes unnecessary heating and air-conditioning costs.
The European standard EN 13779 evaluates the CO₂ concentration in indoor rooms in four quality levels from high to low indoor air quality. From a concentration of 2,000 ppm the indoor air quality is considered hygienically unacceptable.
The CO₂ concentration depends on room size, ventilation situation, number and activity of the persons as well as on duration and frequency of room use. Combustion processes, for example from smoking, candles or open fires, and fermentation processes can also increase the values.
What the “School” is not
- It is not a calibrated measuring instrument, but a visual system for assessing indoor air quality
- It does not replace supply and exhaust air systems or their air-conditioning controls
- It is intended only for dry indoor rooms in which there are no technical installations with carbon dioxide under pressure
- It must not be operated in potentially explosive atmospheres
- It has neither flashing light nor alarm tone nor sensor button; this equipment is offered by other traffic light variants of the manufacturer
- It must not be permanently unplugged at night, otherwise the auto-calibration cannot work correctly
- The device is not approved for any use other than that described
Manufacturer’s notes
- Read the operating instructions thoroughly before installation and first commissioning, especially follow the safety instructions, and keep them for future reference
- Packaging material is not a toy and does not belong in children’s hands
- Do not open the device; it contains no parts that you need to maintain
- Keep the traffic light completely away from moisture
- The standards according to which the product was assessed provide for use in residential, commercial and industrial areas as well as in small businesses, each connected to the public low-voltage network
- When the red stage is reached: stay calm, open all doors and windows and ventilate regularly with a cross-draught instead of leaving windows permanently tilted
- The declaration of conformity is available for download on the manufacturer’s website
Warranty, guarantee and disposal
The “School” is subject to the statutory warranty of at least 2 years in the EU. The manufacturer Elektrotechnik Schabus additionally offers a 5-year guarantee that can be registered online. Repair and spare parts are available directly from the manufacturer, also beyond the statutory warranty.
As an electrical appliance the “School” does not belong in household waste (WEEE Reg. No. DE91394868). Information on the take-back of waste electrical equipment can be found on the manufacturer’s website.
Why the “School” is suitable
Specially for schools
Threshold values based on hygiene recommendations for school operation, without flashing light and alarm tone.
Clearly visible
Distinctly recognisable signal light, also suitable for larger rooms.
Ventilate and save energy
Targeted ventilation saves heating and air-conditioning costs; the traffic light itself consumes very little power.
Reliably calibrated
Auto-calibration on a 7-day cycle, deliberately optimised for everyday school life.
Simply installed
Wall bracket and plug-in power supply unit; everything important is in the box.
Usefully expandable
Ball protection grille, anti-theft device, stand and extension cable as accessories.
From the manufacturer
Made in Germany, German manufacturer since 1992, personal expert advice without call centre, ISO 9001:2015 certified.
Service included
5-year guarantee can be registered, repair and spare parts directly from the manufacturer.
Areas of application
- Classrooms and teaching rooms
- Assembly halls, gymnasiums and sports halls
- Group rooms, school corridors and libraries
- Seminar rooms, lecture halls and training centres
- Tutoring and educational rooms
- Kindergartens
- Rooms in public buildings with public access, according to EU standard EN 13779
- Waiting areas and corridors, for example with anti-theft device
- Spacious rooms and open-plan offices, for example with stand
The Schabus “School”: fresh air without freezing.
Frequently asked questions
What is the “School” suitable for?
The “School” monitors the CO₂ concentration in the room air and reminds users with a clearly visible 3-colour traffic light to ventilate in good time. It was specially developed for classrooms, training rooms and educational institutions.
When does the traffic light switch?
Yellow lights from 1,000 ppm, red from 2,000 ppm. There is no additional flashing stage and no alarm tone. As soon as the traffic light lights yellow, open a window and ventilate until it lights green again.
Why does the “School” have no alarm tone and no sensor button?
This variant is based on the RKI recommendation for switching thresholds in classrooms and is supplied for uninterrupted teaching without flashing light and alarm tone. Therefore there is also no sensor button for muting. Other traffic light variants of the manufacturer offer an alarm tone and touch field.
Is the “School” a measuring instrument?
No. It is not a calibrated measuring instrument, but a visual system for assessing indoor air quality and for reminding users to ventilate.
May I unplug the traffic light overnight?
No, please do not. The traffic light uses the night-time rest periods for auto-calibration. It remembers the lowest CO₂ concentration of the last 7 days and aligns itself to its zero point on this cycle. Only in the event of operational interruptions of more than one week, for example during school holidays, may it be unplugged.
Do the LEDs light at night as well?
In complete darkness the LEDs are dimmed after approx. 10 minutes in order to save energy. The sensor remains active. In brightness or when CO₂ values rise to the yellow stage the LEDs switch back to full brightness immediately.
Where and at what height should I mount the traffic light?
As far as possible from the nearest window or door, at a height of approx. 1.8 to 2.0 m, clearly visible for the whole room. Maintain a minimum distance of 30 cm from corners, edges and the ceiling. Not behind curtains, in cupboards, above a cooker or sink and not next to ventilation, fan or air-conditioning unit.
How do I test the traffic light?
Once a month blow gently with pursed lips from a distance of about 30 to 50 cm in the direction of the sensor grille. The traffic light jumps to red within up to 60 seconds and then, when you move away, goes via yellow back to green. You test the LEDs by switching the operating voltage off and on again.
What does yellow flashing mean?
This is a fault that the traffic light has detected itself. Unplug it, wait approx. 5 minutes and put it back into operation. If the fault remains, operate the traffic light for approx. 30 minutes in fresh air. If that does not help either, contact the manufacturer.
How do I clean the sensor?
Blow the dust off the sensor gently and regularly. Do not use compressed-air devices and keep moisture and humidity away.
What do I do when the traffic light is red?
No panic; there is still no danger to life for a long time. However, open all doors and windows and ventilate thoroughly. Close the windows again as soon as the traffic light shows green. Regular cross-ventilation is better than leaving windows permanently tilted.
Which housing colours are available?
Available are white (RAL 9016), grey (RAL 7032) and green (RAL 6024); further RAL colours on request. The “School” has no further options beyond this.
What accessories are available?
Ball protection grille (Art. No. 300947), anti-theft device (Art. No. 300948), metal stand (Art. No. 400110) and extension cables in 1.5 m, 3 m, 6 m and 10 m. The accessories are not included in the scope of delivery and are ordered separately.
How long is the warranty valid?
The statutory warranty of at least 2 years in the EU applies. In addition, the manufacturer Schabus offers a 5-year guarantee that can be registered online.
Questions about the CO₂ traffic light “School”?
Our support team in Germany will advise you free of charge on selection, installation and configuration.
CO₂ Traffic Light "School" – For Fresh Air in the Classroom
The CO₂ Traffic Light "School" was specially designed for schools, classrooms, and learning environments. It reliably monitors CO₂ concentration and uses a clear traffic light system to indicate when ventilation is needed – supporting better concentration, healthy learning, and a pleasant indoor climate.
Technical Data
- Operating voltage: 12 V DC (plug-in power supply)
- Cable length: approx. 150 cm (power supply), approx. 80 cm (indicator unit)
- Protection class: IP 20
- Dimensions (H×W×D): 303 × 55 × 80 mm
- Color: Green (RAL 6024)
Sensor & Measurement
- Accuracy: ±100 ppm up to 3000 ppm, ±5% up to 5000 ppm
Alert Levels / Indicator Thresholds
- 1000 ppm CO₂: Recommendation to ventilate
- 2000 ppm CO₂: Clear ventilation warning
Environmental Conditions
- Operating range: +5 °C to +45 °C
- Humidity: 10–90% rH (non-condensing)
Manufacturer information:
Electrical engineering Schabus GmbH & Co. KG
Baierbacher Straße 150
83071 Stephanskirchen
Germany
Telephone: +49 80 36 / 674 979 – 0
Email: info@elektrotechnik-schabus.de
Responsible person:
Didactum® Security GmbH
Im Mühlenfeld 4
48163 Münster
Deutschland
Fon:
(+49) 250 19 71 63 54 / (+49) 171 33 11 577
Email: info@didactum-security.de
