Carbon dioxide (CO₂) is a naturally occurring gas we exhale with every breath. While it’s harmless at low levels, elevated concentrations in indoor spaces can impact health, comfort, and productivity. As commercial building operators strive to create healthier indoor environments, understanding CO₂’s role in air quality has never been more critical. 

The Impact of CO₂ Indoors 

What increases the levels of CO₂? The number of people, the amount of time they spend there, and the activity or level of respiration. Indoors, concentrations can quickly rise when spaces are poorly ventilated or crowded. Studies suggest that CO₂ levels above 1,000 ppm may lead to symptoms like fatigue, headaches, and impaired cognitive performance, particularly in workplaces and schools. Studies have shown that a 400 ppm rise in CO₂ levels correlates to a 21% decrease in cognitive function scores. 

High CO₂ levels often signal insufficient ventilation, meaning other pollutants like VOCs or particulate matter may also be accumulating. According to RESET IAQ Standards, CO₂ levels should be kept below 963 ppm to maintain optimal indoor air quality. Considering that indoor air accounts for the majority of the air we breathe daily, it’s crucial to monitor the air quality we rely on. Monitoring CO₂ is a valuable proxy for identifying areas where ventilation and air quality improvements are needed. 

How Do You Know If You Have a CO₂ Issue? 

Detecting a CO₂ issue isn’t always straightforward, as the gas is colorless and odorless. However, there are signs to watch for: 

• Frequent complaints of discomfort such as increased respiratory issues, fatigue or headaches among occupants. 
• Unpleasant stuffiness in the air, especially in high-occupancy areas. 
• Declining productivity or reduced cognitive function making it challenging to concentrate and make decisions in workplaces. 

The best way to identify a CO₂ issue is through real-time indoor air quality monitoring. Sensors that measure CO₂ levels can provide insights into problem areas and guide corrective actions. 

The Role of HVAC and Air Purification 

To manage CO₂ effectively, ventilation is key. HVAC systems excel at ventilation, but their actions are mainly based on maintaining temperature and are often not equipped with sensors for CO₂ or other IAQ metrics.  

Air purifiers are highly effective at eliminating various airborne pollutants, but their capacity to directly reduce carbon dioxide (CO₂) in indoor spaces is minimal. This is because CO₂ molecules are small and not easily captured by conventional filtration systems, such as HEPA filters or activated carbon filters. While air purifiers may not directly eliminate CO₂, they can indirectly influence CO₂ levels by reducing dust and enhancing overall indoor air quality in several ways:  

• Improved Air Circulation: Some air purifiers are equipped with fans that boost airflow within a room. This increased circulation can help distribute fresh outdoor air more effectively, which may help dilute indoor CO₂ concentrations. 

• Reduction of CO₂ Sources: By removing pollutants, odors, and emissions from combustion or other indoor activities, air purifiers can help minimize factors that contribute to higher CO₂ levels. 

• Enhanced Indoor Comfort: By improving air quality, air purifiers create a more comfortable environment, potentially reducing the need to open windows or doors for ventilation—an important factor in areas with high outdoor pollution or allergens. 

Zoned air quality systems, such as Fellowes Array, take these basic elements of air purifiers but increase the value by allowing for localized control, ensuring high-traffic areas receive the attention they need. 

• Advanced Monitoring: Sensors in both air purification units as well as stand-alone monitors continuously track CO₂ levels, providing real-time data that helps identify areas needing better ventilation or air circulation. 

• Increasing Air Exchanges in Zones: By targeting specific zones identified as having high CO₂ rates, these systems enhance the rate of air exchanges to better support ventilation goals, ensuring optimal air turnover in high-occupancy areas like conference rooms or classrooms. 

• Proactive Adjustments: Advanced technology in zoned systems adapts to changing occupancy patterns, automatically adjusting to maintain air quality without overburdening energy systems or overloading an HVAC system. 

Air quality systems ensure that the air people rely on is consistently clean and safe. Whether it’s improving productivity, supporting occupant well-being, or aligning with sustainability goals, zoned air quality systems are an essential tool for creating healthier indoor spaces.  

The Fellowes Array system is a groundbreaking IAQ solution designed to work alongside HVAC systems, addressing indoor air quality challenges, including elevated CO₂ levels. Here’s how: 

• Advanced In-Unit Monitoring: All Array air purifiers include an advanced suite of sensors that continuously track CO₂ levels and other key pollutants in real-time. By providing data with its Viewpoint cloud-based dashboard, facility managers gain a comprehensive understanding of indoor air quality trends, enabling them to identify areas with ventilation challenges with increased CO₂ rates. Viewpoint provides facilities managers the access to take action immediately from their dashboard, without having to engage with any units directly in person. 

• Stand-alone IAQ Monitoring: A versatile solution for air quality management, stand-alone monitors provide another option into real-time insights of CO₂ levels. These devices, such as Array Signal, offer flexible installation options, including portable units that do not require permanent installation. They connect securely through LTE to the Viewpoint dashboard, eliminating the need for an ethernet connection or IT department support for Wi-Fi access. Additionally, they monitor a comprehensive suite of air quality metrics beyond CO₂, including particulates (PM10, PM2.5), temperature, humidity (RH), and TVOCs. 
• Increased Air Changes: By targeting specific zones identified with high CO₂ levels, Array’s powerful fan design enhances air exchanges without adding stress on the HVAC system, adding 3-5 equivalent air changes per hour (eACH). This ensures critical areas like conference rooms or classrooms are well-ventilated and maintain healthy CO₂ levels. 
• Occupancy Awareness: With EnviroSmart™ + technology, Array adapts to changing occupancy, automatically adjusting to maintain air quality and energy consumption. 
• Coordinated Response: Fellowes Array stands out as the only solution offering this capability. When an Array purification unit identifies high CO₂ levels and other increased contaminants, additional units in the assigned shared area are alerted to increase fan speeds. This unique, proactive networking enhances air exchanges and ensures optimal air quality across the entire space. 

With Array, you’re not just monitoring CO₂—you’re actively helping manage it for healthier, more productive indoor spaces. By ensuring consistently clean and safe air, Array helps to maintain optimal conditions for occupant health and well-being. 

Next Steps: Approaching CO₂ in Your Indoor Air Quality Strategy 

Beyond comfort, managing CO₂ levels aligns with broader performance and health goals. A well-ventilated, low-CO₂ environment supports productivity, reduces sick days, and enhances occupant confidence—key priorities in today’s commercial spaces. 

Take the first step toward creating healthier indoor environments. Start by assessing your air quality and understanding how CO₂ monitoring fits into your overall strategy. Work with IAQ experts who can create a customized plan tailored to your space and needs. A simple investment in monitoring and mitigation can lead to profound benefits for your space and the people in it.  Fellowes is ready to help! 

Suspect high CO₂ levels your space? Find out where your air stands with a free IAQ assessment.