One fan, two tents?

hello everyone!

I have a 3x3x6 tent with an inline fan rated at 440cfm. Using the carbon filter as a scrubber with negative pressure, the air flows up from ... carbon filter , through air cooled hood , the inline fan is next, then exits tent.

I just added a small veg/clone tent next to that tent, it's small 3x2x3h, now my plan is to put a "y" duct split at the fan inside the big tent, let one side of the "y" duct be air flow for the air cooled hood etc, then the other 'y' duct side would go from the fan to the smaller tent and withdraw that air out and exit the same as the other air.

I'm sure I have enough cfm for this area, and everything sounds fine to me, just would like other opinions or ideas on this, or if you think this is a solid plan already and what you would tweek.

Also there will be a small 4 inch carbon filter in the small tent that the air will be pulled from, to create negative pressure in the tent.

Thanks!
 

justugh

Well-Known Member
hello everyone!

I have a 3x3x6 tent with an inline fan rated at 440cfm. Using the carbon filter as a scrubber with negative pressure, the air flows up from ... carbon filter , through air cooled hood , the inline fan is next, then exits tent.

I just added a small veg/clone tent next to that tent, it's small 3x2x3h, now my plan is to put a "y" duct split at the fan inside the big tent, let one side of the "y" duct be air flow for the air cooled hood etc, then the other 'y' duct side would go from the fan to the smaller tent and withdraw that air out and exit the same as the other air.

I'm sure I have enough cfm for this area, and everything sounds fine to me, just would like other opinions or ideas on this, or if you think this is a solid plan already and what you would tweek.

Also there will be a small 4 inch carbon filter in the small tent that the air will be pulled from, to create negative pressure in the tent.

Thanks!
your taking spliting the drawl ...........it can be done but u need a Wye with a dampner and the ducting lenght plus the place ment of the fan
(but all this is done with out carbon filters .....adding those changes how the air is drawl ....to use a carbon filter effectivly u need to have it on 1 line with a matched fan CFM rating)

so u can spilt it but run it open or u need to put in 2 ducting paths and match the filters to the fans

(if u put it on a spilt ducting the air is going to travel path of least energy so the carbon will only get sucked over in a section wearing the life of the filter down since the same area is always being drawlen over at some point the carbon can no longer aborb the smell ) it is why u always match the filter to the fan so the suck is even and u get your full 12/15 months
 

justugh

Well-Known Member
a Wye on the ejection point will work
but the power of the air needs to be close .....if u try to dump a 170 cfm and a 400 cfm the 400 cfm will dump out and back flow little down the 170 cfm line stalling the 170 air path u would lose power on the 170 cfm line
 
Thanks for the reply justugh, I was just thinking the same thing from the time I posted, that the air would only take one path or I would have to have a damper to control which way the air would flow.

I think what I will do is put the carbon filter in the small tent, and just get its own fan to scrub the tent, or even run a duct to the bottom of my bigger tent, the temp is always cool in the small tent anyway, this way filter air is going into the flower room then scrubbed out into the room again, kind of double filtration through the the two tents, no y needed
 
In addition if I take this route I would have to still leave the vents open on the bottom for the passive air to flow, if I just rely on the fresh air coming from the small tent, I would think the bigger fan may over power the duct to the small tent and draw on the life and quality of the carbon filter , both filters in that case.
 

justugh

Well-Known Member
Thanks for the reply justugh, I was just thinking the same thing from the time I posted, that the air would only take one path or I would have to have a damper to control which way the air would flow.

I think what I will do is put the carbon filter in the small tent, and just get its own fan to scrub the tent, or even run a duct to the bottom of my bigger tent, the temp is always cool in the small tent anyway, this way filter air is going into the flower room then scrubbed out into the room again, kind of double filtration through the the two tents, no y needed
why would u want to dump used air into the flowering tent it is only going to lower the natural C02 lvls
 

WeedFreak78

Well-Known Member
If you just ran a length of duct from the small tent to the large tent, the neg. pressure in the large tent will draw through the ducting. The scrubber in the large tent will scrub all the air. pretty simple..so small tent intake>small tent exhaust>duct>large tent intake>carbon filter>hood>fan>large tent exhaust.
If the small tent is for veg there really isn't need for a carbon filter, and as long as you keep neg. pressure in both the one filter will handle it.
 
If you just ran a length of duct from the small tent to the large tent, the neg. pressure in the large tent will draw through the ducting. The scrubber in the large tent will scrub all the air. pretty simple..so small tent intake>small tent exhaust>duct>large tent intake>carbon filter>hood>fan>large tent exhaust.
If the small tent is for veg there really isn't need for a carbon filter, and as long as you keep neg. pressure in both the one filter will handle it.
That is very simple that should work just fine, I have some extra flexible duct lying around to try anyway, thank you!
 
It worked out great, the negative pressure works very well, only issue I have is the light that leaks into the flower room through the ducting at the bottom, do you suggest anything to block the light but not air flow?
 

justugh

Well-Known Member
It worked out great, the negative pressure works very well, only issue I have is the light that leaks into the flower room through the ducting at the bottom, do you suggest anything to block the light but not air flow?
back flow dampner

a little light will leak
 
Thanks a lot man, I just bent them in elbow positions, put a s bend in the duct, and cut some panty hose up and stretched it over each end....now to get someone to zip me up in the tent
 

WeedFreak78

Well-Known Member
Is it the typical silver ducting? Can you get a piece of black ducting? If it's silver, one option is to take the duct section, stretch it out and spray flat black paint inside. Other options include putting nylons or landscape fabric over the intake end of the duct..also stops bugs,etc..but will reduce airflow..you'll have to determine if it's too much in your situation. Or just put more S-J-U bends in the ducting. I've seen where people put fiberfil - the material used to stuff pillows/stuffed animals - in their ducts..again it will reduce airflow, but I think if you fluffed it/thinned it and did a light pack it wouldn't be TOO bad.. again..trial and error..You could build a lightproof box around your intake side of the ducting..could be just a cardboard box with some baffles.
 

thelionsden

Well-Known Member
Hi I'm having difficult decisions on a similar situation and was wondering if I you could help I have to vent the duct of hood an tent with one fan is it doible
 
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