CO2 Monitor FAQ: Choose, Set Up, and Understand Your Sensor

VisiblAir offers repairable, open-source monitors with local data access and model-specific choices for battery logging, connected indoor monitoring, fixed Ethernet/PoE installations, and outdoor sensing.

Use the current model comparison for prices, availability, and purchase or quote paths. For deployment planning, see the office guide or school guide.

VisiblAir's battery-powered sensors are charged via a USB-C port, providing a convenient and widely compatible charging method.

Monitoring air quality is essential for maintaining good health, as poor air quality can significantly impact your physical and mental well-being. Here's why:

1. Respiratory Health

• Particulate Matter (PM): Inhaling fine particles (PM2.5 and PM10) can irritate the lungs, aggravate asthma, and contribute to chronic respiratory diseases like bronchitis and emphysema.
• Carbon Dioxide (CO2): Elevated indoor CO2 levels can reduce oxygen intake, causing shortness of breath and other respiratory discomforts.

2. Cognitive Performance

High levels of CO2 and other indoor pollutants like VOCs (volatile organic compounds) can impair cognitive functions, including concentration, decision-making, and productivity.

3. Cardiovascular Health

Long-term exposure to air pollution, particularly fine particulate matter, has been linked to heart disease, high blood pressure, and an increased risk of strokes.

4. Allergies and Asthma

Indoor allergens such as dust mites, mold, and VOCs can worsen allergies and trigger asthma attacks. Monitoring air quality helps mitigate exposure to these triggers.

5. Sleep Quality

High CO2 levels and poor ventilation in bedrooms can disturb sleep patterns, leading to fatigue and decreased overall health.

6. Children's Development

Children are particularly vulnerable to air pollution, which can affect lung development and increase the risk of developing respiratory illnesses later in life.

7. Vulnerable Groups

Elderly individuals and those with pre-existing conditions are more susceptible to the adverse effects of air pollution. Monitoring helps in creating a safer environment for them.

8. Wildfire Smoke and Seasonal Changes

During events like wildfires or in heavily polluted areas, monitoring air quality becomes critical for avoiding short-term health risks like headaches, coughing, and eye irritation.

Benefits of Monitoring

• Preventive Action: Detect poor air quality early to implement solutions such as improving ventilation or using air purifiers.
• Awareness: Understand the sources of pollutants in your environment and how daily activities impact air quality.
• Informed Decisions: Adapt behaviors (e.g., opening windows, adjusting HVAC systems) based on real-time data.

Monitoring air quality empowers you to create a healthier living and working environment, minimizing health risks and enhancing overall well-being.

Yes. VisiblAir ships all available products to the United States. Listed prices and checkout totals are in Canadian dollars (CAD), and shipping is calculated at checkout. Duties and import taxes are not included and are the buyer's responsibility.

Where applicable, choose the USA / Canada USB-C charger or order without a charger. U.S. orders receive the same 12-month warranty and return and repair handling: returns must be authorized and shipped to VisiblAir by tracked service at the customer's expense; VisiblAir pays shipping back to the customer for covered warranty work.

Schools, offices, and multi-unit buyers can request a quote.

VisiblAir sensors equipped with particulate matter (PM) measurement capabilities can effectively detect elevated levels of fine particles, such as PM2.5, prevalent in bushfire smoke. By monitoring these particles, the sensors can alert you to deteriorating air quality due to smoke.

However, while these sensors detect increased PM levels, they may not provide specific warnings about bushfire smoke. For safety, use them alongside local air quality advisories and public health recommendations during bushfire events.

Differences in readings between your VisiblAir device and other air quality sensors can occur due to:

1. Sensor Calibration
   • Factory Variance: Sensors may be calibrated differently by manufacturers.
   • Offset Adjustments: Adjust your VisiblAir device's temperature or humidity offsets to align with actual conditions.
2. Sensor Technology
   • Different sensing technologies (e.g., NDIR vs. MOS for CO2) can result in variations.
3. Placement and Environmental Factors
   • Airflow, proximity to heat sources, or ventilation differences can affect readings.
4. Device Settings
   • Sampling intervals and firmware versions can influence accuracy.

VisiblAir supports sustainability and the right to repair. Options include:

• Print a Replacement Case: Download STL files for 3D printing.
• Order a New Case: Contact VisiblAir for pre-made replacements.
• Temporary Fixes: Use adhesives or tape for short-term repairs.

We're sorry to hear you're experiencing issues with your VisiblAir sensor. Please follow these steps to resolve the problem:

1. Contact VisiblAir Support
   Reach out directly to VisiblAir's support team for personalized assistance. You can email them at info@visiblair.com.
2. Provide Detailed Information
   Include the following in your email:
   • The model of your sensor.
   • A clear description of the issue.
   • Troubleshooting steps you've already attempted.
   • Relevant photos or screenshots that illustrate the problem.
3. Consult the User Manual
   Review the user manual that came with your sensor for troubleshooting tips. If you don't have a physical copy, you can access the manual online at VisiblAir's official website.
4. Check Online Resources
   Visit the VisiblAir website for additional support materials, FAQs, and potential solutions to common issues.

By following these steps, the support team can assist you effectively and promptly.

Fine particles, also known as particulate matter (PM), are tiny airborne particles that affect air quality and health. They are categorized by their diameter:

1. PM10
   • Size: Particles with a diameter of 10 micrometers (µm) or less.
   • Comparable Size: About 1/7th the width of a human hair.
   • Sources: Dust, pollen, mold, and crushed minerals.
   • Health Impact: Can be inhaled into the upper respiratory tract, causing irritation and aggravating asthma or other conditions.
2. PM2.5
   • Size: Particles with a diameter of 2.5 micrometers (µm) or less.
   • Comparable Size: About 1/30th the width of a human hair.
   • Sources: Combustion (e.g., car engines, wildfires, power plants), industrial emissions, and secondary particles formed in the atmosphere.
   • Health Impact: Can penetrate deep into the lungs and enter the bloodstream, increasing risks of heart and lung diseases.
3. Ultrafine Particles (UFPs)
   • Size: Particles with a diameter of less than 0.1 micrometers (100 nanometers).
   • Comparable Size: Smaller than most viruses.
   • Sources: Vehicle exhaust, industrial processes, and indoor combustion (e.g., cooking, candles).
   • Health Impact: Can enter the bloodstream and cross into organs, potentially affecting cardiovascular and neurological health.

Why Size Matters

• Larger Particles (PM10): Typically trapped in the nose or throat, causing irritation but less likely to reach the lungs.
• Smaller Particles (PM2.5 and UFPs): More dangerous as they bypass the body's defenses and reach deeper parts of the respiratory and circulatory systems.

Understanding particle sizes is crucial for monitoring air quality and protecting your health.

Yes, VisiblAir's Wi-Fi-enabled sensors are designed to function both with and without an active Wi-Fi connection. Here's how they operate:

Without Wi-Fi Connection

• Data Storage: The sensors continue to measure and record data internally. For example, the Model C stores measurements in its internal memory during offline periods.
• Data Upload: When Wi-Fi connectivity is restored, stored data is automatically uploaded to the cloud portal, ensuring no information is lost.

With Wi-Fi Connection

• Real-Time Monitoring: The sensors transmit data to the cloud portal at configurable intervals, allowing for real-time monitoring and analysis.

This dual functionality ensures continuous air quality monitoring, providing flexibility and reliability in various environments.

VisiblAir's devices are designed to function independently of their cloud services, ensuring continued local operation even if the company ceases operations. Here's how:

Local Functionality

1. Data Storage
   Devices like the Model C and Model G store measurements internally, allowing access to historical data directly from the device.
2. Open-Source Firmware
   VisiblAir utilizes open-source technology, enabling users to customize and manage their devices without relying on proprietary software.

Accessing Data Without Cloud Services

• Direct Device Access: Retrieve data directly via USB or other local interfaces, depending on the model.
• Third-Party Integration: The open-source nature of the devices allows integration with alternative platforms or personal servers for data management.

This design ensures your VisiblAir device remains functional, providing continuous air quality monitoring regardless of the company's operational status.

To maintain accuracy, check the calibration of your VisiblAir sensor every 6 to 9 months.

1. Take the sensor outdoors: Keep it at least 6 feet (2 meters) away from people, vehicles, windows, doors, and exhaust sources.
2. Let it stabilize: Wait 5 to 10 minutes before evaluating the reading.
3. Check the CO2 value: If the concentration is between 400 and 450 ppm, the sensor is still within the expected outdoor range.
4. Recalibrate if needed: If the reading falls outside that range, recalibration is advised.

Regular calibration checks help maintain accurate indoor air quality readings. Read the full calibration guide.

On the VisiblAir Model E-Lite, Model O and current Model X2, volatile organic compound activity is represented using the Sensirion VOC Index. It is a relative 1–500 signal, not a direct TVOC concentration: 100 is the sensor's adaptive recent baseline.

• VOC Sources: Building materials, cleaning products, and personal care items.
• Index purpose: Values above or below 100 indicate deterioration or improvement relative to the room's recent conditions. They are not universal health thresholds.

Learn how the VOC Index baseline adapts and how to investigate changes.

CO2 itself isn't a virus or harmful, but its levels are an indicator of ventilation quality. Poorly ventilated spaces with high CO2 levels mean exhaled air isn't being replaced effectively, increasing the risk of airborne virus transmission, like COVID-19.

By monitoring CO2, you can assess ventilation in real time and take actions to improve airflow, reducing the likelihood of virus spread.

For offices and classrooms, the best model depends on whether you need quick spot checks, local logging, cloud access, or a fixed networked deployment.

• Model D: battery-powered CO2 logging for inspections, classrooms, and spaces without Wi-Fi.
• Model E-Lite: connected CO2, PM2.5, VOC, temperature, humidity, and pressure monitoring with cloud access.
• Model O: fixed multi-sensor monitoring with Ethernet, optional PoE, Wi-Fi, and broader sensing for larger rooms or building deployments.

Compare all VisiblAir models to match the sensor to your space. See the office and commercial-building guide or the school and classroom guide for rollout guidance.

Yes. Model O is the PoE-ready VisiblAir option for fixed indoor air quality monitoring. It supports Ethernet, optional PoE, Wi-Fi, and USB-C, and monitors CO2, PM, VOC, NOx, temperature, humidity, and pressure.

NDIR means non-dispersive infrared. It is a common CO2 sensing technology that measures how CO2 absorbs infrared light. Dual-beam NDIR designs add a reference channel, while photoacoustic sensors use a different measurement method.

Read the NDIR vs dual-beam CO2 sensor guide for a deeper comparison.

On NOx-capable VisiblAir sensors such as Model O, the NOx value is reported as the Sensirion NOx Index. It helps show whether nitrogen oxide-related air quality is getting cleaner or dirtier over time.

NOx can be associated with combustion sources such as gas stoves, vehicle exhaust, attached garages, and some heating appliances. The index is useful for trends and event detection, but it is not a direct ppb concentration and does not replace a regulatory gas analyzer.

Rebreathed fraction of air (RFA), also written as f, estimates how much of each breath was previously exhaled by other people in the same indoor space. VisiblAir calculates this estimate from CO2 and displays it as a percentage on supported CO2 sensor and cloud portal views.

Following the method in Dr. Jeff Gilchrist's shared-air calculator, the current VisiblAir calculation is:

RFA (%) = max(0, (indoor CO2 − 415 ppm) / 38,000 ppm × 100)

For example, at 1,000 ppm CO2, the estimated RFA is about 1.5%. This means about 1.5% of the inhaled air is estimated to be collective exhaled air from other occupants.

RFA is an estimate, not a direct measurement of another person's breath, infection risk, pathogens, or ventilation rate. It assumes a 415 ppm outdoor background and 38,000 ppm exhaled-breath concentration. Actual outdoor CO2, occupant activity, sensor accuracy and placement, and non-human CO2 sources such as combustion can affect the result. See the calculator and Rudnick and Milton's 2003 paper for the methodology.