Let’s Talk About Carbon Monoxide Sensors for Building Automation Systems

Posted by AJ Phillips on 5th Jul 2024

So today, we're gonna talk a little bit about carbon monoxide (CO) sensors. While they can be paired most commonly with nitrogen dioxide (NO₂) sensors, this article is mostly focusing on just carbon monoxide. You know, they kind of go hand-in-hand, but it really just depends on the application. The majority of these sensors are used to control exhaust in parking garages according to the International Mechanical Code. They ensure adequate airflow in occupied spaces and overall alert occupants of elevated gas levels. You can wire or program these things to directly control exhaust fans.

Why Carbon Monoxide Sensors Are Important

Carbon monoxide is a silent killer. It’s colorless, odorless, and can be lethal in high concentrations. Sources of CO include gas furnaces, water heaters, fireplaces, and vehicle exhausts. High levels can cause serious health issues, including headaches, dizziness, confusion, and even death. So, monitoring CO levels in buildings, especially in areas like parking garages and boiler rooms, is crucial for occupant safety.

How to Choose the Right Sensor

Of the several models that we offer or are available in the marketplace, there are really only a few specifications you can use to filter down to get a better idea of what product is best for you. We don't focus on price. At the end of the day, it's about the application, the customer, and the safety of the people this is protecting.

When someone calls us looking for a particular CO or CO and NO₂ sensor, the first question we ask is whether they want an analog output or if they need a sensor that communicates via BACnet or Modbus. This basically eliminates 50% of the offering. Next, we ask for specifics about the job, such as how many relay outputs they need and where they plan to mount the sensor because it's important to know if it's wall or duct mount. It's also helpful to know if it's going to be in a parking garage or a more industrial area.

Types of Carbon Monoxide Sensors

There are several models of CO sensors available, but we’ll focus on a few that are really useful and popular in the market.

1. Belimo Gas Monitor

The Belimo Gas Monitor is versatile and can monitor up to two gases simultaneously.

Key Features:

Measured Values: CO and/or NO₂
Output Signals: Analog outputs (2 to 10 V or 4 to 20 mA) and relays for direct control of ventilation systems including options for CAN bus abd BACnet MS/TP for integration into building management systems
Installation: Typically installed 3 to 7 feet from the floor, depending on the gas type
Alarm System: Audible and visual alarms for high CO levels

This monitor is suitable for large areas, offering coverage of up to 7500 square feet with a properly designed communication protocol for networked systems.

2. Senva TG UL Series Dual Toxic Gas CO/NO₂ Sensor/Controller

The Senva TG UL Series offers both CO and NO₂ sensing in one unit, providing a comprehensive solution for toxic gas monitoring.

Key Features:

Analog and BACnet/Modbus Protocols: Options for flexible integration
Field Replaceable Sensing Elements: Easy maintenance and long-term reliability
Audible Alarm and LED Indicators: Immediate alerts for high CO levels
Control Options: Can act as a standalone controller with relay outputs for exhaust fan operation

This sensor is particularly useful for applications requiring dual gas monitoring, such as parking garages and mechanical rooms, ensuring adequate ventilation and air quality control.

3. TG0R Value Series Recessed Wall CO/Refrigerant Sensor

The TG0R Value Series is designed for maximum safety in various environments, offering high accuracy CO readings and versatile safety features.

Key Features:

High Accuracy CO Readings: 0-5/10V/2 and 3-wire 4-20mA CO transmitter
Relay, LED, and Audible Alarms: Provides local annunciation and alert
Sleek Design: Fits standard wall plate sizes, ideal for schools or hotels
UL2034 Recognized CO Sensing Element: Ensures reliable performance

This sensor is great for detecting CO in indoor environments and is especially useful in places like hotels and schools where safety and unobtrusiveness are key.

4. BAPI-Stat "Quantum" Carbon Monoxide Sensor

The BAPI-Stat "Quantum" Carbon Monoxide Sensor is a sophisticated device designed for reliable CO detection in building automation systems.

Key Features:

Measurement Range: 0 to 40 ppm
Accuracy: ±3% of Full Scale
Analog Output Options: 0 to 5VDC, 0 to 10VDC, or 4 to 20mA
Relay Trip Point: 30 ppm with an audible alarm
LED Indicators: Green/Red LEDs indicating unit status (Normal, Alarm, Trouble/Service, Test)
Sensing Element Life: Typically 7 years
Certifications: RoHS compliant

This sensor is ideal for monitoring air quality in commercial buildings, providing both visual and audible alarms when CO levels exceed safe limits.

5. ACI CO Duct Series Carbon Monoxide Duct Sensor

The ACI CO Duct Series monitors CO levels and is designed for continuous monitoring of vehicle exhaust in non-hazardous areas.

Key Features:

Measurement Range: 0 to 125 ppm
Operating Temperature: -4°F to 104°F
Accuracy: ±2.5% of Reading
Relay and Buzzer Options: For immediate alerts and control

This sensor is perfect for applications like parking garages, arenas, kitchens, and loading docks, ensuring safe air quality in various settings.

Installation and Maintenance

Proper installation and maintenance of CO sensors are critical for their effective operation.

Installation Guidelines

Placement: CO sensors should be installed 3 to 7 feet above the floor, as CO has a similar density to air.
Coverage Area: Ensure sensors cover the intended area without obstructions.
Wiring: Follow local building codes and manufacturer guidelines for wiring and communication setups.

Maintenance Tips

Regular Calibration: Calibrate sensors annually to maintain accuracy.
Replace Sensing Elements: Replace elements as recommended by the manufacturer, typically every 5 to 7 years.
Test Alarms: Periodically test audible and visual alarms to ensure they function correctly.

Carbon monoxide sensors are a vital component of building automation systems, protecting occupants from the dangers of CO exposure. By understanding the features and applications of various sensors, building managers can make informed decisions to enhance safety and air quality. Whether for parking garages, mechanical rooms, or commercial buildings, selecting the right CO sensor ensures compliance with safety standards and promotes a healthy indoor environment.

For more information on specific products, please visit the following links:

All of our sensors have five or seven year warranties, and we pride ourselves on the technical support capabilities for any of our customers purchasing these products through our website, ZOTsupply.com

By leveraging these advanced CO sensors, building automation systems can effectively manage air quality, ensuring the safety and well-being of all occupants.