Active Air fan speed contoller?

I just ordered a active air speed controller for my exhaust fan. My fan is 347 CFM in a 4x4x8 grow tent. What should I set my active air speed controller to? I don't want to set it too low and it doesn't do the job of exhausting the air. But I do want to make it run quieter and use less electricity.

The balance between positive and negative pressure is key. I like to have slightly neg pressure. Each room is different, as there is no magical setting. Trial and error.

Close the tent completely you should see the sides suck in keep it balanced between not to sucked in and the bulb temp but your hand under the bulb cooler the bulb closer the light bigger the buds

Use it as a temperature thermostat

Let the temperature dictate what speed you set it to , too warm turn it up too cool turn it down.

For anyone wondering , might as well start it at 1/2 speed and adjust as necessary.

I use the same controller with a 8 inch fan , it has fine adjustments and only a little bit of motor hum.

Get a temp/RH controller and then plug the fan speed controller into that and set the fan around half speed. Temp stays just right all the time and the fan stays nice and quiet when it runs. Mine turns on and runs about 10 min out of every half hour and the temp stays withing 2 degrees C all day. A thermostat on a heater keeps it the same during the dark period.

I'm using a 6" inline fan while running a 1000W HPS in a 7x8x6.5'h room. Not sure how many CFM the fan is rated for as it has no identity plate but it sounds like a jet engine at full blast. I put a meter on it and it uses 120W wide open so I dialed it back to 60W and put a little mark on the cover for the speed controller so I I can reset it if I need to crank it up. Seems to work fine with the carbon filter connected too.

A 347 CFM fan in a 4x4x8 space gives you 22 ach.