Fresh air inlet.

How are you guys running a fresh air inlet in your tent? Running it all the time or running it when the carbon filter exhaust is running? I don’t have mine installed yet and it seems I have a good amount of negative pressure. What say you.

I'm using an approximately 14" long and 4" diameter PVC 90 degree elbow. It's secured to the lower left intake vent and I'll let the exhaust fan draw air in through the intake then move the intake air around the tent with three small fans set on low.

One fan is on the floor to help stir the intake air around the root zone and gently push it up into the canopy.

One fan is about 1/2 up the tent and gently stirs the air in and around the canopy. The third is just below the bottom of the lights to eliminate any potential hot spots around the surface of the lights and the top of the canopy.

There is no need for an intake fan with this set-up. And yes, my exhaust fan is running 24/7.

What is 'fresh air'? Are you trying to pull in air just to replace co2 the plants have used? why not hang a co2 bag or portable canister instead?

I have a 6 inch inline fan connected to a temp sensor to dump the air through 6 inch tubing out a window when my temps get too high. This pulls in air from the room the tent is in, but i lose around 10% of my humidity. which is easily replaced by a humidifier with a controller. I could hook up the fan to the humidity controller to act as a dehu if needed.