Carbon Dioxide Comfort Levels

CO2 acceptance and comfort levels

Indoor air quality includes

  • temperature
  • odor
  • high or low levels of gases

Since CO2 is exhaled by people at predictable levels the content of Carbon Dioxide - CO2 - in air may be a significant indication of air quality.

A measure of CO2 indicates the amount of fresh air supply:

  • 15 cfm ventilation rate per occupant corresponds to 1000 ppm CO2
  • 20 cfm ventilation rate per occupant corresponds to 800 ppm CO2

Normal CO2 Levels

The effects of increased CO2 levels on adults at good health can be summarized:

  •  normal outdoor level: 350 - 450 ppm
  • acceptable levels: < 600 ppm
  • complaints of stiffness and odors: 600 - 1000 ppm
  • ASHRAE and OSHA standards: 1000 ppm
  • general drowsiness: 1000 - 2500 ppm
  • adverse health effects expected: 2500 - 5000 ppm
  • maximum allowed concentration within a 8 hour working period: 5000 ppm  

The levels above are quite normal and maximum levels may occasionally happen from time to time.

Extreme and Dangerous CO2 Levels

  • slightly intoxicating, breathing and pulse rate increase, nausea: 30,000 ppm
  • above plus headaches and sight impairment: 50,000 ppm
  • unconscious, further exposure death: 100,000 ppm

Carbon Dioxide Standard Levels

The recommendation in ASHRAE standard 62-1989 are

  • classrooms and conference rooms 15 cfm per occupant
  • office space and restaurants 20 cfm per occupant
  • hospitals 25 cfm per occupant

Related Topics

  • Physiology - Human physiology, air quality and comfort temperatures, activity and metabolic rates, health effects of carbon monoxide and more

Related Documents

Tag Search

  • en: CO2 comfort levels parts per million ppm
  • es: Niveles de confort CO2 partes por mill√≥n ppm
  • de: CO2 Komfortstufen ppm ppm

Search the Engineering ToolBox

- "Search is the most efficient way to navigate the Engineering ToolBox!"

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your SketchUp model with the Engineering ToolBox - SketchUp Extension/Plugin - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro. Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

Translate the Engineering ToolBox!
About the Engineering ToolBox!