At what point ,

Techman

,percentage,does CO2 % in the air affect the body/mind/etc,. I had worked for an exercise place that had 35 adults doing heavy exercise in a 25'x35'x 8' room for 45min. with AC only and 0% O.A..?????????????????

Larry (from OSHA)

Well

The OSHA permissible exposure for an 8 hour period is 5000 parts per million.  That's 1/2%.  The short term exposure limit is 30,000 parts per million (3%).



http://www.osha.gov/dts/chemicalsampling/data/CH_225400.html



Hope that helps.



Larry

BillW

CO2

Thank you, Larry, for posting the info.  Nice to work with you again.

 Techman... CO2 is the "usual suspect" in any IAQ investigation where people compalin of feeling tired or sleepy, usually in the afternoon.  The culprit is often no or not enough fresh air ventilation, and the cure is a minimum position outside air damper, and a CO2 sensor that either speeds up the fan and/or or allows the O/A damper to modulate.  The OSHA figures are for the factory floor, and not for comfort in a home or "office" occupied space.  There are commercial CO2 sensors available, and they are part of a commercial building control system.  I don't know of any residential type units, and unless a home has an ER/HR ventilation system, there is no way of introducing fresh air into the typical system without increasing the heating/cooling load.

Techman

CO2

O.K. so would there be not enough CO2 in the air in the exercise room after 20-30-45min to worry about?Thank You!

BillW

Excercise room

You could hire an environmental engineer to come in and measure the level, buy a direct-reading co2 monitor or use a length-of-stain chemical detection tube to give you a reading.  There are hand pumps and tubes available from Draeger and Bendix, and they are useful in getting "ballpark" numbers in IAQ investigations.  It would seem to me that ventilation would be needed for not only co2, but the "aroma" of many hard-working bodies as well.  It sounds like a good application for an ER/HR ventilation system.  I doubt that you would exceed the TLV levels just from excercise.