Air purifiers are a great solution to keep indoor air quality high. They filter out many pollutants, toxic gasses, such as PM 2.5, allergens and reduce asthma triggers, dust and unpleasant odors.

air purifier a living room, air cleaner removing fine dust in house

Can Air Purifiers Remove CO2

However, as concerns about global warming and elevated carbon dioxide (CO2) levels in indoor spaces grow, making sure we know how to go about good air quality in homes, offices and other indoor spaces is fundamental.

In this article, we will discuss CO2 and its implications and discuss how a good air purifier can improve indoor air quality.

What Are The Implications of CO2?

CO2 is a naturally occurring gas that’s essential for life. Plants consume it during photosynthesis, and animals exhale it as a byproduct of respiration.

However, elevated levels of CO2 can have adverse effects on health and the environment. In terms of the broader environment, increasing CO2 levels contribute to global warming. Inside our homes and other indoor environments, high concentrations can lead to reduced cognitive function, headaches, and fatigue.

As the implications of CO2 are far-reaching and encompass more than just the atmospheric or indoor air quality concerns, it’s vital to keep them in mind. We have categorized them in three main groups.

Global Climate Change

The Greenhouse Effect

CO2 is a primary greenhouse gas, meaning it can trap heat in the Earth’s atmosphere. While the greenhouse effect is natural and essential for life on Earth, elevated levels of CO2 intensify this effect. This leads to an overall increase in global temperatures, a phenomenon commonly referred to as global warming.

Melting Polar Ice and Rising Sea Levels

As global temperatures rise, polar ice caps and glaciers melt at an accelerated rate. This contributes to rising sea levels, which can result in the loss of coastal habitats and increased flooding.

Shifts in Weather Patterns

Elevated CO2 levels can lead to more frequent and severe weather events, such as hurricanes, droughts, and heavy rainfall. These unpredictable patterns disrupt ecosystems, agricultural activities, and can cause significant infrastructural damage.

Human Health Implications

Cognitive Impairment

Studies have indicated that high concentrations of CO2 in indoor environments can impair cognitive functions. This can lead to reduced focus and productivity, difficulty in decision-making, and a general decline in mental acuity.

Respiratory Issues

Although CO2 is not directly toxic, high indoor concentrations can indicate poor ventilation, which means other pollutants and pathogens might be present. This can exacerbate respiratory conditions like asthma and can lead to the spread of airborne diseases.

Discomfort and Other Symptoms

Elevated levels of CO2 can lead to symptoms like headaches, dizziness, shortness of breath, and fatigue. Over time, persistent exposure to high CO2 levels indoors can also contribute to a feeling of malaise or general discomfort.

Ecological and Biological Impact

Ocean Acidification

CO2 is absorbed by the world’s oceans, where it reacts with seawater to form carbonic acid. This acidification affects marine life, especially coral reefs and shellfish, by reducing the availability of minerals needed to form shells and skeletons.

Altered Plant Physiology

While plants require CO2 for photosynthesis, excessively high levels can alter plant growth, nutrient content, and water usage. This can have cascading effects on ecosystems and the animals that depend on these plants for food.

What are the optimal levels of CO2?

Although a natural component of the air we breathe, the concentration of CO2 in the air matters for both environmental and health reasons.

Historically, the atmospheric CO2 levels hovered around 280 parts per million (ppm) for thousands of years. With the onset of the industrial revolution and increased deforestation, these levels began to rise significantly. By 2021, the global average exceeded 410 ppm, a level many scientists deem as concerning for climate change.

From an indoor air quality perspective, maintaining optimal CO2 levels is vital for health and well-being. The Occupational Safety and Health Administration (OSHA) sets the permissible exposure limit for CO2 at 5,000 ppm over an 8-hour workday. However, even at levels as low as 1,000 ppm, some people might experience drowsiness or reduced cognitive function.

For optimal indoor air quality, it’s recommended to maintain CO2 levels between 400 ppm and 600 ppm. This range ensures comfort, maximizes cognitive function, and indicates good ventilation. In spaces where many people gather, like conference rooms or classrooms, having effective ventilation is crucial to prevent CO2 levels from rising and adversely affecting occupants.

Direct CO2 Removal: Challenges and Innovations

The easiest way to reduce CO2 indoors is ventilation. Just open windows and doors to keep the air fresh at all times if you have a chance.

However, if the space lacks ventilation, you need to consider alternatives.While traditional air purifiers might not be effective at removing CO2, the growing concern over indoor air quality has spurred innovation. There are emerging technologies and systems specifically designed to remove or convert CO2 from the atmosphere, both on large and small scales.

Direct air capture (DAC) is one such technology that captures CO2 directly from the ambient air. These systems use chemicals that bind to CO2 and then release it once heated. Once captured, the CO2 can be stored or even converted into other products. However, DAC is primarily being developed for large-scale environmental applications and isn’t yet a feasible solution for household air purifiers.

Another potential solution is the integration of plants or algae systems with indoor environments. As natural CO2 absorbers, certain plants can enhance indoor air quality by consuming CO2 during photosynthesis. Some modern architectural designs and indoor setups integrate green walls or algae systems, effectively combining nature and technology to enhance indoor air quality.

The Mechanism Behind Air Purifiers

Air purifiers typically employ several mechanisms to clean the air. The most common one is the use of High Efficiency Particulate Air (HEPA) filters. These filters are designed to capture particles as small as 0.3 microns in diameter, including dust, pollen, and some microbes. Another typical component is activated carbon or charcoal filters, which are adept at removing gasses and odors by adsorbing them onto their surfaces. Then there are other technologies like UV light or ionizers which target microorganisms.

However, when it comes to CO2, things get a bit more complicated. CO2 is a very small and stable molecule. Traditional air purifier technologies, like HEPA and activated carbon, aren’t designed to capture or convert CO2 molecules. While activated carbon can absorb some gasses, CO2 isn’t easily adsorbed unless under specific conditions, like extremely high pressure or when used in conjunction with other technologies.

Maintaining Indoor Air Quality

Given the challenges associated with directly removing CO2 with household air purifiers, it might be more pragmatic to approach the issue by addressing the sources of CO2 and ensuring proper ventilation.

Ventilation plays a pivotal role in maintaining indoor air quality. Regularly allowing fresh air to circulate in indoor spaces can dilute the concentration of indoor pollutants, including CO2. This can be achieved through natural means, like opening windows, or mechanically via ventilation systems.

Furthermore, being mindful of activities that can lead to high CO2 levels can also help. For instance, limiting the number of people in a confined space, ensuring combustion appliances are well-maintained and vented, and integrating plants into the living space can all contribute to maintaining healthy CO2 levels.


In conclusion, while traditional air purifiers may not effectively remove CO2, there are measures we can adopt to ensure our indoor environments remain healthy. Innovation in this area is ongoing, and we might soon see advancements that can directly address CO2 levels in indoor spaces.

Until then, understanding the sources of indoor CO2 and adopting strategies to mitigate its accumulation will be key.

Proper ventilation, coupled with mindful living habits, can go a long way in ensuring the air we breathe indoors remains fresh and healthy.

Air Purifiers Remove CO2, Can Air Purifiers Remove CO2?, Days of a Domestic Dad