Model: AI-CO2
Carbon Dioxide Transmitter
A wall mounted photoacoustic CO₂ transmitter for demand controlled ventilation, with RS485 Modbus, analog outputs and an optional relay. Measures up to 20,000 ppm.
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- Sensor
- Photoacoustic (PAS), Swiss made
- Range
- 0-2,000 up to 0-20,000 ppm
- Accuracy
- ±(40 ppm + 3% of measured value)
- Outputs
- 4-20mA or 0-10V, optional RS485 Modbus
Description
The Ace Instruments Carbon Dioxide Transmitter (AI-CO2) uses the latest sensing technology to deliver a flexible, feature packed room CO₂ monitor. It measures a wide range of readings, up to 20,000 ppm, with customizable ranges of 0-2,000 ppm, 0-5,000 ppm, 0-10,000 ppm and 0-20,000 ppm. That makes it a good fit for a wide variety of commercial and industrial applications.
The transmitter supports CO₂ monitoring across smart agriculture and smart buildings, including greenhouses, hospital laboratories, cold storage, retail spaces, offices and educational institutions.
The AI-CO2 is available with an LCD display or as a blind transmitter with no display. Communication and control options include RS485 Modbus, 4-20mA output, 0-10VDC output and an optional relay output for ventilation control.
Choose your display option, a duct mounting variant, and optional relay and buzzer alarms that alert you to threshold violations. Our engineers will help you co develop the right solution for your application.
How it works
Install the transmitter at breathing height (1.0 to 1.5 m) in occupied rooms. It feeds real time CO₂ data to the HVAC control system, enabling demand controlled ventilation. Instead of ventilating on a fixed schedule, the BMS adjusts fresh air supply to the measured CO₂ concentration: more ventilation as occupancy rises, less when rooms are quiet. The result is better air quality with lower energy use.
How photoacoustic (PAS) sensing works
The sensor pulses infrared light through a small chamber of room air. CO₂ molecules absorb specific infrared wavelengths and warm slightly, creating tiny pressure changes that a microphone detects. The stronger the signal, the higher the CO₂ concentration.
Like other optical methods, PAS involves no chemical reaction and no consumable element to wear out. That gives excellent long term stability and accuracy for continuous CO₂ monitoring in occupied building spaces.
BMS integration
With optional RS485 Modbus communication, the transmitter feeds real time CO₂ data into a Building Management System. This enables automated ventilation control, centralized monitoring across many rooms, and demand controlled ventilation based on measured, occupancy driven CO₂ levels rather than fixed schedules.
Features
New generation photoacoustic (PAS) sensor
The AI-CO2 uses advanced Photoacoustic Spectroscopy sensors, the latest in carbon dioxide sensing. PAS gives highly accurate CO₂ measurements with strong reliability and long term stability, which suits real time monitoring and demand controlled ventilation.
RS485 Modbus communication
The transmitter integrates with building management systems (BMS) over RS485 Modbus. Users can keep records and take corrective action when readings deviate.
With or without display
The display is optional. Choose a blind transmitter that talks directly to a PLC, or add the LCD readout for local monitoring.
Optional relay output (CO/NO/NC)
An optional relay output lets the AI-CO2 trigger exhaust fans and other ventilation systems directly.
Applications
Demand controlled ventilation
Adjusts ventilation to real time CO₂ levels to optimize air quality. Cuts energy cost by avoiding over ventilation at low occupancy.
Commercial buildings
Offices, malls and hospitality spaces. Supports smart HVAC control and helps meet workplace ventilation regulations.
Educational institutions
Monitors CO₂ in classrooms. Fresh air helps prevent drowsiness and supports focus.
Healthcare facilities
Supports optimal air exchange in patient rooms and operation theaters, which matters for infection control and sterile conditions.
Green buildings
Fits sustainable designs with energy efficient ventilation. Better IAQ metrics help toward LEED and BREEAM certification.
Residential complexes
Adds real time air quality monitoring to smart home systems for healthier enclosed spaces.
Industrial facilities
Monitors CO₂ in confined workspaces and production areas to protect workers and support regulatory compliance.
Public transport hubs
Maintains safe ventilation in crowded stations and airports, improving comfort and reducing transmission risk.
Laboratories and cleanrooms
Supports controlled environments where precision is critical, helping prevent contamination of sensitive equipment and experiments.
Compliance
- ASHRAE (American Society of Heating, Refrigerating & Air Conditioning Engineers)Supports ASHRAE Standard 62.1 by helping keep CO₂ no more than 700 ppm above outdoor levels.
- OSHA (Occupational Safety and Health Administration)Helps keep CO₂ exposure below the permissible exposure limit (PEL) set by OSHA, supporting workplace safety.
- LEED (Leadership in Energy & Environmental Design)Prioritizes CO₂ monitoring in line with LEED v5 requirements for continuous indoor air quality monitoring.
- GRIHA (Green Rating for Integrated Habitat Assessment)Uses the latest CO₂ sensing technology to support GRIHA 2019 compliance.
- WELL (International WELL Building Institute)Supports ventilation effectiveness through integration with WELL mandated demand controlled ventilation systems.
- Health CanadaMakes it easy to follow Health Canada's indoor CO₂ exposure guideline, with multiple integration options.
- Additional complianceGovernment of Dubai, Health and Safety Department.
Specifications
| Sensor type | Photoacoustic sensor (Switzerland) |
|---|---|
| Measuring range |
|
| Accuracy | ±(40 ppm + 3% of measured value) |
| Analog output | 4-20mA or 0-10VDC (user field selectable) |
| Communication (optional) | RS485 Modbus |
| Power supply | 24 VDC, 200 mA |
| Response time | <3 minutes for a 90% step change |
| Warm up time | <2 minutes; 10 minutes for maximum accuracy |
| Storage conditions | −10 to +60 °C |
| Dimensions | 125 (H) × 80 (W) × 30 (D) mm |
| Display | LCD display (optional) |
| Mounting | Wall (with or without display) or duct enclosure |
| Relay (optional) | 1 relay output (NO/CO/NC), freely programmable, rated 2 A |
| Buzzer (optional) | Optional programmable built in buzzer alarm for high, high high and extreme high alarms |
Need wiring details or a dimensional drawing? They are in the brochure below, or ask our engineers.
Download specifications
Technical details for your IAQ solution, in one PDF.
Frequently asked questions
What is the AI-CO2 Carbon Dioxide Transmitter?
The AI-CO2 is a wall mounted carbon dioxide transmitter that continuously measures indoor CO₂ concentration. It provides accurate real time CO₂ data to Building Management Systems (BMS), PLCs and HVAC controllers, to help maintain healthy indoor air quality and energy efficient ventilation.
What does the AI-CO2 measure?
It continuously measures carbon dioxide (CO₂) concentration in parts per million (ppm). The value helps building operators judge ventilation effectiveness and maintain a comfortable indoor environment.
Why is carbon dioxide monitoring important?
Carbon dioxide is an excellent indicator of indoor air quality and occupancy. As more people occupy a space, CO₂ rises. Elevated levels can signal inadequate ventilation, leading to drowsiness, reduced concentration, discomfort and poor air quality. Continuous monitoring helps ensure occupied spaces get enough fresh air.
How does the AI-CO2 measure CO₂?
The AI-CO2 uses a photoacoustic (PAS) sensor. It detects how much infrared light CO₂ molecules absorb and reports the concentration in parts per million (ppm).
Values are shown locally on the optional display and sent to the Building Management System over Modbus RS485 for monitoring and control.
What is photoacoustic (PAS) sensing technology?
PAS is an optical gas sensing method. CO₂ absorbs pulsed infrared light, and the resulting pressure changes are picked up by a microphone. It offers excellent long term stability, high measurement accuracy and minimal maintenance, and suits commercial buildings, hospitals, schools, laboratories and HVAC applications.
Where should a wall mounted CO₂ transmitter be installed?
Install it at breathing height, typically 1.0 to 1.5 metres above the floor. Avoid:
- Windows
- Doors
- Spots directly below air supply diffusers
- Exhaust vents
- Dead air spaces
The ideal location is the area with the highest expected occupancy, so the reading represents the indoor environment.
Where is the AI-CO2 commonly installed?
Typical applications include:
- Office buildings
- Schools and universities
- Hospitals and healthcare facilities
- Conference rooms and classrooms
- Hotels
- Shopping malls
- Airports
- Laboratories
- Commercial and government buildings
How does this transmitter connect to a Building Management System (BMS)?
The AI-CO2 communicates with Building Management Systems using Modbus RTU over a standard 2 wire RS485 network.
Multiple transmitters can share one RS485 bus, which keeps installation simple and cost effective.
Can the AI-CO2 improve HVAC energy efficiency?
Yes. The AI-CO2 supports demand controlled ventilation by letting the BMS adjust fresh air supply to actual occupancy. This maintains healthy indoor air while reducing heating and cooling energy use.
What CO₂ level is considered acceptable indoors?
Recommended limits vary by application, but many commercial buildings aim to keep indoor CO₂ below 800 to 1,000 ppm. Staying in that range generally indicates adequate ventilation and supports occupant comfort and productivity.
Can the AI-CO2 be integrated with a Building Management System (BMS)?
Yes. It supports industry standard communication options:
- Optional RS485 Modbus communication
- 4-20mA output
- 0-10VDC output (user field selectable)
These options allow integration with Building Management Systems, PLCs and SCADA systems.
Is the AI-CO2 suitable for continuous monitoring?
Yes. It is designed for reliable 24×7 operation in commercial, educational, healthcare, pharmaceutical and industrial applications.
Does the transmitter require calibration?
The AI-CO2 is factory calibrated before shipment. Periodic verification is recommended to maintain long term accuracy, particularly in critical indoor air quality applications.
Is installation easy?
Yes. The compact wall mounted design allows quick installation and simple integration with HVAC systems and Building Management Systems. It suits both new buildings and retrofit projects.
What are the advantages of using the AI-CO2?
Key benefits include:
- Continuous CO₂ monitoring
- High accuracy photoacoustic (PAS) sensing
- Support for demand controlled ventilation
- Better indoor air quality
- Easy BMS and PLC integration
- Multiple communication options
- Reliable industrial grade performance
- Low maintenance
Who typically uses the AI-CO2?
It is widely used by:
- Facility managers
- HVAC contractors
- Building automation integrators
- Hospital engineering departments
- School administrators
- Commercial building operators
- Laboratory managers
- Pharmaceutical manufacturers
- Industrial maintenance engineers
- Green building consultants
Why choose Ace Instruments?
Ace Instruments has over 30 years of experience manufacturing indoor air quality and HVAC monitoring solutions. Customers choose our products for their measurement accuracy, reliable PAS sensing, industrial grade construction, easy BMS integration, responsive technical support, and proven performance across commercial, healthcare, educational, pharmaceutical and industrial applications.
How do I choose the right Carbon Dioxide Transmitter?
The right AI-CO2 depends on your application, communication needs, output signal, installation location and monitoring goals. Our application engineers can help you select the most suitable transmitter for offices, schools, hospitals, laboratories, commercial buildings, healthcare facilities and other environments where continuous CO₂ monitoring and energy efficient ventilation matter.
Is the AI-CO2 a suitable alternative to Greystone CD2RMC, Honeywell C7232, Siemens QPA, or Belimo CO2 monitors?
Yes. The AI-CO2 is designed as a dependable alternative for indoor air quality and HVAC CO₂ monitoring applications commonly handled by products such as:
- Greystone CD2RMC Series (CD2RMC, CD2RMC-24, CD2RMC-A, CD2RMC-D)
- Greystone CEDT Series (CEDT-C2D-X, CEDT-C2W-X, CEDT-C2R-X)
- Honeywell C7232 Series (C7232A1008, C7232B1006, C7232A1040)
- Honeywell TR42 IAQ Series (TR42, TR42A, TR42A-U)
- Siemens QPA Series (QPA2000, QPA2002, QPA2062)
- Belimo 22RC Series (2RC-51, 22RCM-51, 22RTM-59)
The AI-CO2 offers:
- Accurate photoacoustic (PAS) carbon dioxide sensing, with customizable ranges
- Stable long term monitoring performance
- Analog and Modbus communication options
- Easy integration with BMS, PLC and HVAC systems
- Reliable indoor air quality monitoring for commercial and industrial environments
- A compact wall mount enclosure for easy installation
It suits offices, hospitals, laboratories, schools, commercial buildings, pharmaceutical facilities, cleanrooms and industrial HVAC applications. Consider it for projects that are evaluating alternatives to comparable CO₂ monitoring systems from these brands.
Greystone, Honeywell, Siemens, Belimo and other mentioned brands are trademarks of their respective owners. Ace Instruments is not affiliated with or endorsed by any of these companies.
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