How often is air exchanged in YOUR setup

I've read numbers from it should be once a minute to 5x a minute, curious of some peoples actual air exhange rate in their grow setup, how often is air exchanged in your grow?

rather WHEN you exchange your air, the exhaust fan should be able to cycle it in 3-5 minutes
take the volume of room and divide this by 3-5
this should be the minimum rating of exhaust fan you should have.
You want this to happen when room temps get to hot.
However, many people will run their fans on low constantly also to help manage scents (assuming they are using a carbon filter etc..)
Another common practice is to cycle the room once an hour.

For my space I'm setting it up to always run on low. And then cycle it once per hour, and also to kick in when temps get above 83

my tent is 5'x5'x6'6'' my exhaust is 170 CFM. i use 400w mh for veg. 600w hps w/ super lumens feature on the lumitek ballast for flower. nothing but excellent results!

Do u run Co2?

No c02 and a 6.5x6.5x6.5 tent with 1000wmh for veg and 1000hps for flower

If you aren't running CO2 the more air you can exchange the better. Your plants are only working with ambient amounts of CO2 which is around 100-400ppm at the very most, and plants can soak this up very quickly. The more air you exchange the more CO2 is brought in and the faster and stronger your plants will grow!

my tent is 4' x 4' x 6' and i run 2 fans that are rated at 500 cfm, i buff the intake fan a little to create a negative pressure effect, i dont use co2

4x4x6 tent=96m3 fan is a 350cfm so 3.64 times a minute air gets changed, no CO2