HVAC CO2 Detector with Relay

CO2 MonitorPart Number: ESTON-07

  • Easy-to-install CO2 detector with an in-built relay
  • Ideal for controlling a ventilation fan for indoor air quality and comfort
  • Low cost and low maintenance
  • Ideal for controlling fans in a single room or small building
  • LED visual alarm


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The ESTON-07 CO2 Detector with Relay lets you simply and easily monitor and control indoor air quality. Use it to visually monitor air quality with its easy-to-read colored LEDs that quickly change from green to yellow to red as indoor air quality changes. When air quality gets too poor, its built-in relay can be used to turn on ventilation to bring in fresh, outdoor air.

With its one-button on/off/auto ease of use and industry-standard 24V power requirements, the ESTON-07 CO2 Detector with Relay is perfect for homes, offices, meeting rooms, classrooms, or anywhere monitoring and controlling indoor air quality is important for occupant’s comfort.


Alarms and Relays

CO2 DetectorThe ESTON-07 has a set of visual alarm indicators via LED lights that are located on the lower left corner of the meter. The alarms and relays are strictly for indoor air quality for comfort purposes. The maximum range of the ESTON-07 is 2,000 ppm which may be too narrow for certain applications.

The ESTON-07 should only ever be installed inside general occupancy buildings such as homes, offices, workplaces, gyms, shopping centres and similar. The ESTON-07 is not suitable for industrial purposes. For more information and further clarification on the use of the ESTON-07, please contact Air Quality Sensors.


  • Non-Dispersive Infrared (NDIR)
  • Sampling Method: Diffusion
  • Range: 0 – 2,000 ppm
  • Accuracy: ± 30 ppm ± 3 % of measured value
  • Life Expectancy: > 15 years


  • 1st green light <600ppm, 1st and 2nd green lights 600-800ppm, 1st yellow light 800-1200ppm, 1st and 2nd yellow lights 1200-1400ppm, 1st red light 1400-1600ppm, 1st and 2nd red lights >1600ppm


Electrical / Mechanical
  • Power Input: 24VAC/VDC
  • Output Relay: <240VAC/30VDC 3A Switching Current
  • Output Relay Control: 800ppm to 1500ppm via jumpers
  • Housing: PC/ABS fireproof plastic; protection class: IP30
  • Maintenance Interval: No Maintenance Required
  • Dimensions: 100mm (H) × 80mm (W) × 28mm (D) or 2×4″ wire box
  • Standard: CE-Approved


  • 1 Year


Recommended Maintenance

Air Quality Sensors recommends the ESTON-07 be checked and re-calibrated (if required) on a regular basis. Air Quality Sensors recommends the ESTON-07 have a calibration and alarm check every 12 months. This can be performed using the fresh air calibration procedure as outlined in the manual. Air Quality Sensors recommends that a full service and calibration check be conducted every 24 months by a qualified technician or by returning the unit to Air Quality Sensors.

Disclaimer: The ESTON-07 is delivered to you checked and calibrated by the manufacturer and Air Quality Sensors. Once the detector is in your possession, it is then your responsibility to ensure its safe operation. Air Quality Sensors, or any of its suppliers, will not be responsible for poor installation, operation or maintenance of the ESTON-07 by the end customer.


Manual and Brochures

Download ESTON-07 Specification Sheet

Download ESTON-07 Manual


Application Notes