Passive/active intakes

BlueBerryMango

Active Member
Hello.

I'm currently running my tent with the 240CFM inline fan, matching filter I believe as it came as a combo.
Tent has the 2 side flaps open to allow the air from IN GROW ROOM to come in. The exhaust is also IN GROW ROOM. Same old air from inside recycles, AC Unit to cool the air around the tent. This is all shown in diagram # 1.

With winter coming in fast, I wouldn't really need the air conditioner anymore!
Should I just get another fan, use the AC ducting from the window to go to the fan, the fan starts pumping air into the tent. Maybe use a controller to stop the fan if the tent is getting "to cold" because winter weather would freeze the tent in minutes, the fan would need to run on the tempature/ humidity controllers just so the fan will turn off/on. Keep the vent flaps open due to the fact the fan will be on and OFF.

Will this push out the smell of budding plants in my growroom if the flaps are open and the fan is pushing air from (with filters and screens) outside into the tent, then the exhaust still running???

In diagram #2 is the few options I'm talking about doing, how could I set this up so I can keep the smell from pushing out of the tent if it will do that, eliminate the Ac unit, and keep tempatures under control.

There is also the idea of using an inline fan to pump air from outside to inside around the tent as the AC unit will do, and again using a temperature/ humidity controller, the fan will turn ON to cool the area around the tent when INSIDE the tent gets a certain temperature, turns OFF when it gets cold enough.

Also as I currently have 1 fan, if I had to get another what one should I get to do the job?

Can someone help me out on what to do or what idea to go with???
 

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n0thing

Well-Known Member
If you're exhausting your hot air into the same room as your passive intake then you will still need an AC. Instead of exhausting into the same room, exhaust outside and you shouldn't need the AC with ambient temps in winter.

For keeping smell from leaking out of your tent you want negative pressure from your exhaust. Hope this helps.
 
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BlueBerryMango

Active Member
If you're exhausting your hot air into the same room as your passive intake then you will still need an AC. Instead of exhausting into the same room, exhaust outside and you shouldn't need the AC with ambient temps in winter.
You didn't understand then.

So I wanna get rid of the AC, the temps inside the grow tent gets to hot (specially for flowering) if I don't run a AC unit beside it.
So with winter coming (not also going to exhaust outside sense I don't run HPS) and even then I can't really do it, maybe use the AC unit exhaust pipe to connect to but I'm trying to keep it alittle on the stealth side

Basically im trying to bring cold air INSIDE my room, or pump it into the tent and exhaust still into the room

also I'm not sure if in winter you'll see alittle steam or whatever from warm exhaust air coming from inside to outside
 

BlueBerryMango

Active Member
If you're exhausting your hot air into the same room as your passive intake then you will still need an AC. Instead of exhausting into the same room, exhaust outside and you shouldn't need the AC with ambient temps in winter.

For keeping smell from leaking out of your tent you want negative pressure from your exhaust. Hope this helps.
Oh and currently I got negative pressure so I'm good, but as I was wanting to pump air into the tent, will this cause a leak??

Along with I got a studio apartment and I don't really have a window, I use a glass sliding door, but I use the Ac window adapter and I made a custom door extension for the door. So I was thinking of bringing cold air in as it's cold enough it could cool the AREA quickly or inside the tent and return that negative pressure in seconds
 

n0thing

Well-Known Member
You didn't understand then.

So I wanna get rid of the AC, the temps inside the grow tent gets to hot (specially for flowering) if I don't run a AC unit beside it.
So with winter coming (not also going to exhaust outside sense I don't run HPS) and even then I can't really do it, maybe use the AC unit exhaust pipe to connect to but I'm trying to keep it alittle on the stealth side

Basically im trying to bring cold air INSIDE my room, or pump it into the tent and exhaust still into the room

also I'm not sure if in winter you'll see alittle steam or whatever from warm exhaust air coming from inside to outside
For a passive intake you need to control the rooms temp, that's your goal. Doing that will control your tents temp. Depending on you lighting, you want your room temp to stay around 65°-70°. For active intake your idea about setting a fan to intake from the outside hooked up to a temperature controller would work in winter only, but you'd need a way to close the intake while the fans not running or it would pull in cold air passively. In summer this idea will not work. You would need an AC in the summer regardless - you can't cool an area with hot air.

Oh and currently I got negative pressure so I'm good, but as I was wanting to pump air into the tent, will this cause a leak??

Along with I got a studio apartment and I don't really have a window, I use a glass sliding door, but I use the Ac window adapter and I made a custom door extension for the door. So I was thinking of bringing cold air in as it's cold enough it could cool the AREA quickly or inside the tent and return that negative pressure in seconds
As long as your intake has a lower cfm rating than your exhaust you'll have negative pressure.
 
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