Intake fan question - recommendation please

I am looking to add an intake fan to my 3x3x7 tent primarily to balance negative pressure and also improve temperature / humidity. I have a 6" Can-Fan Max fan and carbon filter (334cfm / 600cfm respectively) for exhaust. The fan has 3 manual speed setting. I usually have it at the lowest speed and will occasionally increase to 2 depending on temperature. The intake fan needs to fit inside a 22" tall x 15" x 15" box to which my Horti-control shroom filter is attached. I looked at the AC infinity cloudline fans but they are almost 13" leaving very little room for ducting and necessary 90d bend. Another EC controllable fan is TerraBloom

. It is only 7.25" so will fit better.
It is rated at 350 CFM which is much more than I will need.
Any one familiar with this fan. Recommend yes / no.
Other options for compact quiet / reliable intake fan?
Much appreciated… :sunglasses:

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You do have option of opening Pass through hole at bottom of tent. Increase exhaust fan speed a little and pull in lots of fresh air through the bottom an exhaust hot stale air out the top. Control negative pressure inside tent by speed of exhaust fan. Just my thoughts good luck

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The screened opening is on the back of the tent which is up against a wall so access is tough

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I had the same problem bud. I’m not an experienced grower, but I do have 18 years experience as an energy efficient home builder. The rule of thumb with makeup air, wether it be passive or active, is diameter in should equal diameter out.

This rule of thumb didn’t work in my tent with a passive intake, but when I opened up two other vents in the tent the problem was solved.

As far as using an intake fan, you would be perfectly fine using a 6” booster fan like you showed in your post.

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Where do you vent your tent? Into the room, attic, exterior of the house, an adjacent room?

I have an 8" AC Infinity at half speed pushing air into my 5x5 and the same exhaust fan turned up 1 tick more than the input.

Fans can help recirculate heat rather than exhausting the most warm air. If you are in a humid environment you can run a dehumidifier, and a dehumidifier will also put out plenty of warm air.


Using two inline fans would work well, however, booster fans are cheaper and will still accomplish the job of bringing air into your tent. We as growers use inline fans for exhaust because they can accommodate charcoal filters. Booster fans don’t allow for accessories, but they will move air into an environment just as well as an inline fan.

That is other item I need to address. It currently exhaust into the same room where the tent is. The room is conditioned with a dehumidifier. Exhausting into the room is great during winter / dry months. During summer it increases AC and dehumidification needs. The room has an ceiling exhaust fan above the tent which I manually control.

Yup same here. Ideally I would vent to the exterior of the building and draw air in through the room which houses my tent. There is a lot of hot air being exhausted from the tent that is being drawn back in, therefore increasing the amount of heat. As you said I have fixed this problem with an air conditioner (a large dehumidifier is on stand by for humidity issues). This is not the most efficient/cost effective method however.

I’m remodeling and getting ready to sell my house, so I don’t want to add random exhaust ducts up through the roof or through the exterior walls. I’m sure most folks in an apartment would ha e the same issue.

Depending on your setup it would always be an option to vent out a window

Do you have to put the fan in your tent? Why not outside the tent?

Inside, outside, doesn’t make a difference. One would just have to make sure that their ducting originates inside the tent. I found it much easier to install inside my tent as the tent came with straps and load barring poles. I could see installing a fan outside the tent as being ideal if the height was restricted.

My tent is 7’ tall so I don’t have that problem.

no window, tent also 7’

intake of conditioned room air. intake fan will be outside of tent.

Is it your tent we are doing this for? Im confused? Maybe I smoke too much pot? I thought @beardless had the issue? Anyway, height always seems to be an issue when you grow big plants! So the issue is a room inside a room? That compounds the issue a tad. Makes things awkward and expensive to control come summer time.

Just a thought, but would you be able to sinch the intake fan into one of the corded openings at the bottom of the tent. No ducting, no hassle.

Personally, I just keep the “doors” open on my tent all day when the light is on. I use preventative measures for pests, so that’s not a concern.

I’ve hardly had to run my AC at all so far this spring. I’m in VT so when the temps outside reach 80 or above, I run the AC on low speed and turn it off at night.

I’m just trying to help and not looking for advise. My advise is based on my experience. If you are reading his posts it sounds like we have a similar setup. No need to be snarky bud!

@Cannabian all is good. My tent is in my former workshop that is 8x14 in the back of an attached garage. It is connected to one of the home’s AC units.

oh sorry, Im not being snarky. That idea you had about cinching the fan in the hole was my point. Dont put it in the tent. You could put the fan anywhere you want and run ducting to the cinch hole. That was my point. Seriously my snarky is super obvious! No drama here!

No problem. I have a picture of the intake filter and the box it sits on. The problem is unable to upload. Any way thanks for the thoughts and suggestions.

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Yeah lets keep this light and happy shall we? We are all in this together. Solutions is what we need. And anyway its Friday! This was my day

People and their crappy decks in trailer parks! Niw that makes me snarky!
How to fell 120 foot trees over crappy decks! Thats my job every day! Woo hoo!