Kefiw

Archived noindex page. Kefiw's public focus is Property decision help.

Archived page

This older Kefiw page is kept for reference, marked noindex, and removed from the primary sitemap. The current Kefiw experience is focused on property decisions: cost, quotes, damage, buying, selling, owning, and packets.

Go to Property

CO₂ Cognitive Tax

Indoor CO₂ ppm mapped to cognitive decline — vent or vacate above 1500.

Satish 2012 and Allen 2016 established an exposure-response: at 1000 ppm, strategic thinking drops ~15%; at 1400 ppm, 50%; at 2500, 75%. ASHRAE indoor target: ≤ 1000 ppm. Most offices and bedrooms hit 1200–2500 without mechanical ventilation.

Part of: Environmental Stressors

Start below
Fields marked optional can be skipped; results update as you type
CO₂ Cognitive Tax · Indoor Air
Atmospheric Load
0100020005000 OSHA
Status
Elevated
Subclinical decision-making impairment
Cognitive decline
−15%
vs 600 ppm baseline
Satish 2012 / Allen 2016: CO₂ at 1400 ppm halves strategic decision-making performance. ASHRAE indoor target: ≤ 1000 ppm. Standard office/bedroom builds at occupancy: 1200–2500 ppm without mechanical ventilation.

How to use

  1. Read CO₂ from a monitor (outdoor baseline ~420 ppm).
  2. Read cognitive decline, status band, and action.
  3. Open a window or vacate above 1500 ppm for sustained cognitive work.

Examples

1000 ppm (typical bedroom at dawn)
Cognitive decline ~15% · Elevated band · ventilate.

Before you act on the result

Health-related tools are educational planning aids. They can make a number or assumption visible, but they do not diagnose, treat, prescribe, or replace clinician guidance.

If the result points to risk, symptoms, medication questions, or urgent changes, use it as a note for a qualified professional rather than a final decision.

Next up

Room stale? Deep-work capacity collapses with CO2.Deep Work Capacity · Focus Horizon → Ventilation poor? Check thermal limits too.Thermal Failure · WBGT →

Frequently asked questions

› Why does CO₂ affect cognition? Troubleshooting

Mechanism still debated — likely cerebral vasoconstriction and acid-base shift, not hypoxia. Effect reverses within minutes of ventilation.

› What about outdoor CO₂?

420 ppm globally, rising ~2 ppm/year. Indoor ppm = outdoor + occupancy load ÷ ventilation rate.

Tips & related reading

See the Environmental Stressors hub →

Tips & how-tos

Relevant links

Related tools

Thermal Failure · WBGT

Wet-bulb globe temperature — the heat-stress index used by OSHA, ACGIH, and military for work/rest cycle decisions.

REM-Sync · Sleep Cycles

Find the optimal bedtime or wake time based on 90-minute sleep cycles. Wake at the end of a cycle, not the middle.