How do i control vpd

Grow Support
21

Thats what i need to get .the ac infinity humidifier t3 like you have. I cant control the one i have now with the pro 69 controller.

2 Likes
22

Does everybody run their exhaust fan at a minimum even when the temperature is satisfied. It seems that it sucks the humidity from my T3 humidifier right out and the humidifier is running constantly

2 Likes
23

I do. Exhaust at a minimum of 1, intake at a minimum of 0. So that there is always air exchange.

2 Likes
24

Nope, just those calibration adjustments I mentioned for each controller.

1 Like
25

Intake at 0 doesn’t move air @Newt ?

2 Likes
26

Yeah thats it… i thought there was more but no, your good.

27

Is a 6-in intake fan really necessary. I have a 6 inch exhaust fan and on the opposite side and bottom of 10 I have 6 in flexible duct going to a filter box. I figured the exhaust fan would draw the air that it needs instead of opening the vents on the 10th. This way I don’t have to worry about light coming in as well

28

Needed, probably not. Very helpful with forced airflow, 100%.

I use a 4" intake on my tent.

29

I have the T8 for my exhaust. Anything higher than six and it sounds like a jet engine taking off…

1 Like
31

And almost as powerful. I set a plastic bowl on the exhaust port, not thinking, and it vanished. Freaked me out! Had to shut it off, reach down the hose and pull it out

Haven’t done it since.

1 Like
32

It does not.

33

I use 6" exhaust, and 4" intake.

1 Like
34

I’m running an automation mode on VPD. At a minumum, you need humidifier and exhaust devices set on triggers. It wouldn’t hurt to have a heat pad and dehumidifier further dial it in. I’m using a ACI 69 PRO + and set the exhaust with a low trigger and the humidifier with the high trigger. I have seedlings/early veg in the tent so I set my exhaust with a low trigger of .8 and the humidifier with a high trigger of 1.0. That will change in a few weeks to a low of 1.0 and a high trigger of 1.3 kPa. I have the light running a 18/6 cycle. I open the bottom vent during the lights off cycle to pull in some fresh air since the low trigger will be hit most in this six hours. I also measure the temperature of the leaves with an infrared laser thermometer and compare that temp to the ambient temp in the grow room/tent. I use the calculator in the link below to target the recommended LVPD.

The results are not in but the plants seem to like it.