Development and application of an indoor carbon dioxide metric
Open accessAbstract
Indoor carbon dioxide (CO2) concentrations have been considered for decades in evaluating indoor air quality (IAQ) and ventilation, and more recently in discussions of the risk of airborne infectious disease transmission. However, many of these applications reflect a lack of understanding of the connection between indoor CO2 levels, ventilation, and IAQ. For example, a single indoor concentration such as 1000 ppmv is often used as a metric of IAQ and ventilation without an understanding of the significance of this or any other value. CO2 concentrations are of limited value as IAQ metrics, and a single concentration will not serve as a ventilation indicator for spaces with different occupancies and ventilation requirements. An approach has been developed to estimate a space-specific CO2 level that can serve as a metric of outdoor ventilation rates. The concept is to estimate the CO2 concentration that would be expected in a specific space given its intended or expected ventilation rate, the number of occupants, the rate at which they generate CO2, and the time that has transpired since the space was occupied. This paper describes the approach and presents example calculations for several commercial, institutional, and residential occupancies.
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CO2 is considered among the most significant air constituents that impact occupant safety, work productivity, and well-being in the spatial environment.
“is considered among the most significant air constituents that impact occupant safety, work productivity, and well-being in the spatial environment [3].”
From A Microalgae Photobioreactor System for Indoor Air Remediation: Empirical Examination of the CO2 Absorption Performance of Spirulina maxima in a NaHCO3-Reduced Medium (2023) · cites this paper as [3]
The Introduction says that many other indoor contaminants have more significant health and comfort impacts than CO2. It also cautions that reported associations between indoor CO2 and symptoms or performance may reflect lower ventilation and other contaminants, rather than CO2 itself. This runs contrary to describing CO2 as among the most significant constituents affecting occupants. (LLM, conf=0.88)
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Experimental — accuracy not yet measuredCarbon dioxide represents 60~85% of greenhouse gas.
“carbon dioxide (CO2), which represents 60~85% of greenhouse gas (GHG)”
From A Microalgae Photobioreactor System for Indoor Air Remediation: Empirical Examination of the CO2 Absorption Performance of Spirulina maxima in a NaHCO3-Reduced Medium (2023) · cites this paper as [3]
The Introduction discusses indoor CO₂ concentrations in relation to ventilation and air quality, not CO₂’s share of greenhouse gases (page not provided). Searches for greenhouse gases and the 60–85% figure found no passage in our copy addressing that proportion. (LLM, conf=0.76)
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Percentages, sums and reported differences re-computed from the paper’s own numbers.
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Cited by
Sorted by citations
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- Authors
- Persily, A.
- Affiliations
- National Institute of Standards and Technology (US)
- Corresponding author
- Persily, Andrew
- ORCID
- Persily, Andrew
- Venue
- Indoor Air
- Publisher
- Wiley
- Published
- 2022-07
- Volume
- 32
- Issue
- 7
- Pages
- e13059-e13059
- ISSN
- 0905-6947 (ISSN-L)
- 1600-0668
- OpenAlex
- W4286252805
- Cited by
- 104
- References
- 30
- Citations by year
- 2026: 38 · 2025: 22 · 2024: 13 · 2023: 26 · 2022: 4 · 2021: 1
- FWCI
- 6.38
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Licence
- Locations
- Indoor Air (publishedVersion, cc-by-nc-nd)
- PubMed (publishedVersion)
- Topics
- Physical Sciences › Environmental Science › Health, Toxicology and Mutagenesis › Indoor Air Quality and Microbial Exposure
- Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Infection Control and Ventilation
- Physical Sciences › Engineering › Building and Construction › Building Energy and Comfort Optimization
- Keywords
- indoor carbon dioxide, CO2 concentration, indoor air quality, ventilation rate, airborne infectious disease transmission, occupancy, residential buildings, commercial buildings, institutional building
- MeSH terms
- Air Pollutants, Carbon Dioxide, Environmental Monitoring, Respiration, Ventilation, Air Pollution, Indoor
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