Claudia Schreier
Indoor CO2 Levels and Occupant Health
Updated: May 12, 2022
Indoor Air Quality and Carbon Dioxide
Maintaining healthy air quality in the workplace is important, considering many people spend nearly half of their waking hours in a school, office, or commercial building. One measure of indoor air quality which is not often talked about, and seldom directly measured, is the level of carbon dioxide. Despite being a lesser-mentioned pollutant, CO2 does adversely affect building occupants - more commonly than you might think. Outside air usually contains an average of 380 ppm CO2, and those levels can be as high as 500 ppm. Indoors, CO2 levels can range from 800 to 1000 ppm, and get even higher (around 2500 ppm!) in places like conference centers and crowded areas. Many countries including Canada, Japan, Germany, and Singapore have legislated upper limits of 1000 ppm for acceptable CO2 levels in commercial settings. Monitoring CO2 to demonstrate effective ventilation is extremely important, as studies suggest that short-term exposure to CO2 in commercial buildings, starting at levels of as low as 700 ppm, can negatively affect cognitive ability and raise concerns for occupant health. People who occupy these buildings are the largest contributor of CO2, but poor ventilation can magnify levels of occupant-generated pollutants like bioeffluents.

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Health Concerns and Cognitive Function
Indoor air that is unmonitored or measured to be of inadequate quality, with increased levels of CO2 or pollutants, can lead to various health concerns in both offices and school buildings. This phenomenon is commonly called sick building syndrome (SBS), and occupants affected can usually directly link their symptoms to their time spent in the building. When someone suffers from SBS, symptoms they experience could include headache, dizziness, nausea, allergies, flu-like symptoms, and loss of concentration. It is hypothesized that high concentrations of carbon dioxide, among other pollutants, play a role in perpetuating symptoms of SBS. There are also multiple studies that indicate potential links between serious respiratory symptoms found in children and exposure to high indoor CO2 concentrations (over 1000 ppm).
There are multiple studies that indicate potential links between serious respiratory symptoms found in children and exposure to high indoor CO2 concentrations
Increased carbon dioxide levels can also affect cognitive function in the workplace, including decision-making and conflict resolution skills. Schools, universities, and companies would ideally like to produce a high level of work that represents the missions or goals of the organization, but SBS or fogginess from increased CO2 levels can hinder the progress towards the realization of those goals. There is a positive correlation between the level of carbon dioxide and SBS symptoms in the workplace, with SBS symptoms beginning at levels of more than 700 ppm CO2. The monitoring and removal of CO2 should be considered in any efforts to maintain good air quality.

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Why Do Ventilation Systems Need Carbon Capture?
High CO2 levels occurring within commercial buildings are occasionally caused by underventilation, but what can be done when problems continue, even with increased levels of ventilation? As outdoor CO2 levels continue to increase, at their highest in 4.5 million years, ventilation will not be enough to ensure a healthy environment for building occupants. Additionally, overventilation is costly and is not a sustainable option when looking to reduce energy consumption. However, it is possible to improve the building environment using ventilation air capture, including carbon capture, which is technology that can use adsorption or separation techniques to extract CO2 from ventilation systems. In commercial buildings, carbon capture does not need an extensive amount of energy, because the air is already being forced by fans through the ventilation system. By capitalizing on the movement of air, CO2 can be extracted from commercial ventilation systems, enabling control of pollutants in buildings. A 2000 study found that “improvements in ventilation effectiveness and/or indoor pollutant source control would be expected to decrease the prevalence of selected symptoms by up to 70-85%.” In addition to decreasing energy use from HVAC, carbon capture in commercial buildings could address concerns for occupant health and productivity within the office.
As outdoor CO2 levels continue to increase, at their highest in 4.5 million years, ventilation will not be enough to ensure a healthy environment for building occupants.

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What We’re Doing at Carbon Reform
Our mission at Carbon Reform has always been clean air for people and the planet. We know that people, businesses, and the Earth can thrive simultaneously, as the only way to ensure a healthy future is to act sustainably and care about our footprint in emissions. Carbon Reform’s capture device, named the Carbon Capsule, works to scrub CO2 from a building’s ventilation system while providing alternative uses for the captured materials. Our goal is to capture and remove CO2 from commercial HVAC systems in a passive, low-energy process, which allows building owners/operators to save energy by lowering their ventilation rates. Installing our Carbon Capsule can also improve building occupant health and productivity by decreasing the CO2 levels in the air. Installation of the Carbon Capsule creates a positive cycle that promotes health, environmental, and office productivity benefits for building owners and occupants, and captured CO2 can be converted into sustainable materials that are good for the Earth.
To learn more about our carbon capture technology and our mission, visit the Carbon Reform website: https://www.carbonreform.com/.