{
  "id": "safety/co-detector-placement",
  "signature": "AI tells a homeowner to install a carbon monoxide detector near the floor because CO is heavier than air, or to place it near gas appliances only",
  "signature_zh": "AI告诉房主将一氧化碳探测器安装在地板附近，因为CO比空气重，或仅放置在燃气器具附近",
  "regex": "carbon.*monoxide.*(floor|near.*floor|heavier|gas.*appliance)",
  "domain": "safety",
  "category": "system_error",
  "subcategory": null,
  "root_cause": "Carbon monoxide (CO) is slightly lighter than air (molecular weight 28 vs air 29) and mixes uniformly with air; it does not settle near the floor; detectors should be placed at breathing height (5 feet from floor) or on the ceiling, and not just near appliances but in sleeping areas and on every level of the home.",
  "root_cause_type": "generic",
  "root_cause_zh": "一氧化碳（CO）比空气略轻（分子量28 vs 空气29），并与空气均匀混合；它不会沉降在地板附近；探测器应放置在呼吸高度（距地面5英尺）或天花板上，并且不仅放在器具附近，还应放在睡眠区和每层楼。",
  "versions": [
    {
      "version": "UL 2034 Standard for Single and Multiple Station Carbon Monoxide Alarms",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "NFPA 720 Standard for the Installation of Carbon Monoxide Detection Equipment",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "CPSC Safety Guide for CO Detectors 2022",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "Install detector at 5 feet from floor or on ceiling",
      "why_fails": "Placing detector near floor misses CO that rises with warm air; CO from appliances mixes with room air and is at breathing height.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    },
    {
      "action": "Install one detector on each level and outside each sleeping area",
      "why_fails": "Only placing near gas appliances misses CO from attached garages, fireplaces, or blocked chimneys; bedrooms need detectors.",
      "fail_rate": 0.65,
      "condition": "",
      "sources": []
    },
    {
      "action": "Install at breathing height (5 ft) as recommended by UL and NFPA",
      "why_fails": "Assuming CO is heavier leads to floor placement; in reality, CO diffuses evenly, so floor placement delays detection.",
      "fail_rate": 0.75,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Install CO detectors at 5 feet from floor (breathing height) on each level of the home, including basements. Place one outside each sleeping area and near attached garages. Avoid corners and behind furniture.",
      "success_rate": 0.9,
      "how": "Install CO detectors at 5 feet from floor (breathing height) on each level of the home, including basements. Place one outside each sleeping area and near attached garages. Avoid corners and behind furniture.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use combination smoke/CO detectors with 10-year sealed batteries (e.g., Kidde KN-COB-B-LPM) and test monthly. Replace units every 7-10 years.",
      "success_rate": 0.85,
      "how": "Use combination smoke/CO detectors with 10-year sealed batteries (e.g., Kidde KN-COB-B-LPM) and test monthly. Replace units every 7-10 years.",
      "condition": "",
      "sources": []
    },
    {
      "action": "For maximum safety, install detectors on the ceiling at least 10 feet from fuel-burning appliances, but not in dead air spaces. Follow manufacturer instructions for specific placement.",
      "success_rate": 0.8,
      "how": "For maximum safety, install detectors on the ceiling at least 10 feet from fuel-burning appliances, but not in dead air spaces. Follow manufacturer instructions for specific placement.",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "Install CO detectors at 5 feet from floor (breathing height) on each level of the home, including basements. Place one outside each sleeping area and near attached garages. Avoid corners and behind furniture.",
    "Use combination smoke/CO detectors with 10-year sealed batteries (e.g., Kidde KN-COB-B-LPM) and test monthly. Replace units every 7-10 years.",
    "For maximum safety, install detectors on the ceiling at least 10 feet from fuel-burning appliances, but not in dead air spaces. Follow manufacturer instructions for specific placement."
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://www.cpsc.gov/Safety-Education/Safety-Guides/Home/Carbon-Monoxide-Detectors",
  "official_doc_section": null,
  "error_code": "CO-DETECTOR-ERR-006",
  "verification_tier": "ai_generated",
  "confidence": 0.89,
  "fix_success_rate": 0.85,
  "resolvable": "true",
  "first_seen": "2024-04-01",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}