Indoor Air Quality

What is Carbon dioxide (CO2)?

Posted by author-avatar
Comments Off on What is Carbon dioxide (CO2)?

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:

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

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

Extreme and Dangerous CO2 Levels
  • 30.000 ppm -- slightly intoxicating, breathing and pulse rate increase, nausea
  • 50.000 ppm -- above plus headaches and sight impairment
  • 100.000 ppm -- unconscious, further exposure death
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 Posts