{
  "schema": "vedokrok.public-item.v1",
  "release_id": "MHC-RPUB-20260920-75ad787a",
  "url": "/knowledge/use-co2-as-a-ventilation-clue-not-a-complete-indoor-air-quality-score",
  "id": "MHC-D-RESEARCH-0889",
  "version": "0.1.0",
  "title": "Use CO2 as a ventilation clue, not a complete indoor-air-quality score",
  "summary": "CO2 can tell you something about ventilation without telling you everything about the air.",
  "kind": "question",
  "body": "ASHRAE's 2025 position document says indoor CO2 can be useful for understanding ventilation and occupancy, but acceptable IAQ depends on multiple pollutants and conditions. Use the trend as a clue—especially when people enter, windows close or ventilation changes—without declaring a room safe or unsafe from CO2 alone.",
  "limits": [
    "Building, combustion and infection-control concerns can require professional assessment beyond a consumer CO2 monitor."
  ],
  "topics": [
    "union-digital-home-office-environment"
  ],
  "intents": [],
  "source_ids": [
    "RS-864E546A7D0D437F"
  ],
  "evidence": [
    {
      "claim": "ASHRAE's 2025 position document treats indoor CO2 as a useful ventilation/IAQ indicator while emphasizing that IAQ depends on multiple factors.",
      "source_id": "RS-864E546A7D0D437F",
      "role": "supports",
      "note": "Building, combustion and infection-control concerns can require professional assessment beyond a consumer CO2 monitor.",
      "locator": "See source record"
    }
  ],
  "use_when": [
    "A CO2 monitor shows one number and you treat it as the health grade of the whole room."
  ],
  "avoid_when": [
    "Building, combustion and infection-control concerns can require professional assessment beyond a consumer CO2 monitor."
  ],
  "example": "A falling CO2 level after airing the room shows ventilation changed; it does not prove every pollutant is now low.",
  "check": "CO2 informs a ventilation decision without becoming a universal air-quality verdict.",
  "question": "Is the reading changing with occupancy or ventilation? · What is the outdoor/background context? · Could particles, VOCs, humidity or other pollutants matter independently? · What ventilation change can be tested safely?",
  "sources": [
    {
      "id": "RS-864E546A7D0D437F",
      "title": "ASHRAE Position Document on Indoor Carbon Dioxide",
      "url": "https://www.ashrae.org/file%20library/about/position%20documents/pd-on-indoor-carbon-dioxide-english.pdf"
    }
  ],
  "relations": [
    {
      "from": "MHC-D-RESEARCH-0889",
      "to": "MHC-D-RESEARCH-0891",
      "type": "use_before",
      "url": "/knowledge/use-co2-trends-to-test-ventilation-changes-in-the-room-you-actually-work-in"
    }
  ],
  "collections": [
    {
      "id": "RC-112961CC8EF10888",
      "title": "Make the environment carry more of the focus load",
      "url": "/collections/make-the-environment-carry-more-of-the-focus-load"
    }
  ]
}