What size fan for a 4x4 tent?

just setup my tent and i need an exhaust/intake fan still. im going to try and just run 1 fan and see how it turns out.

what size would be best for this situation? my temps are fairly high right now it is in the 80's humidity is also very high here since i live in Hawaii. i was thinking of drawing air from outside into my tent and just letting it exhaust into my room. the air outside is MUCH cooler then the air inside of my house.

also how the hell do i mount a fan to the top? the i got 6 11" holes but i mean how the hell would i set up the fan in general? the closet is inside my room with no space for it and it's up against the window so i can just hang it outside but really no where to put it outside.

Shame you need a tent as just a room with open window and vent fan would probably work wonders.

Fans buy bigger use a variac to reduce speed or try for a good brand with inbuilt speed control for flexibility but again more costly.

Some use el cheapo 4" bathroom extractorvinline fans some go 4" ruck or rhino. I have a six inch high powered ruck on variac and even the lowest speed it suucks plenty air.

These things dont cool only a cool source of air will - in time youll work out wether you can run in room or need to bring in outside air, play about a little just get what works for all.

Moving air isnt that quiet and a pita to sleep with.

Idk but a 4" ruck with speed control for short runs always works well for most.

Full power my ruck will almost implode my 1x1, talk about wind tunnel, once stuck my fingers in it - quite low power thank god as thought i might loose one

Kingrow1 said:

Shame you need a tent as just a room with open window and vent fan would probably work wonders.

Fans buy bigger use a variac to reduce speed or try for a good brand with inbuilt speed control for flexibility but again more costly.

Some use el cheapo 4" bathroom extractorvinline fans some go 4" ruck or rhino. I have a six inch high powered ruck on variac and even the lowest speed it suucks plenty air.

These things dont cool only a cool source of air will - in time youll work out wether you can run in room or need to bring in outside air, play about a little just get what works for all.

Moving air isnt that quiet and a pita to sleep with.

Idk but a 4" ruck with speed control for short runs always works well for most.

Full power my ruck will almost implode my 1x1, talk about wind tunnel, once stuck my fingers in it - quite low power thank god as thought i might loose one

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i was planning to buy this https://www.amazon.com/AC-Infinity-...=exhaust+fa,lawngarden,246&sr=1-1-spons&psc=1

the 4" would best suit me? i bought a tent for various reasons 2 main ones is 1. i can't vent the room otherwise no where to vent it without cutting a huge hole in the closet doors which would of needed to be replaced and 2. i get major light leak in my closet after a while it gets extremely annoying waking up to the light shining in my face.

Lethidox, dude....ac I xfinity is seriously the best fan setup out there! I got mine, it's a t6 with the digital controller. I love it! Thinking of buying a s6 to 0lug into the extra port in the controller and have both and I take and exhaust controlled digitally from the same box that comes with the t6. Totally worth the money.

My ambient room temp where I grow is 73°, and this thing keeps my temps within 5° of the room. I pull from the outside with ducting taped to the bottom of the window screen, and exhaust is scrubbed before exiting the top corner of the pat same window.

AlaskaRob said:

Lethidox, dude....ac I xfinity is seriously the best fan setup out there! I got mine, it's a t6 with the digital controller. I love it! Thinking of buying a s6 to 0lug into the extra port in the controller and have both and I take and exhaust controlled digitally from the same box that comes with the t6. Totally worth the money.

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idk much about fans i just searched "best exhaust fans" and saw a list i think it was from 2018. this was on that list and i liked the sleek look so i looked more into it. i bought the t4 after doing some small research and math pertaining to the cfm and how to calculate all the stuff like humidity and heat and all that. i think the t4 will be okay for my tent.

what size is your tent?

4 inch fan for a 4x4?! I love ac infinity but that just seems way too small. Glad you got the t4 versiin though. With that control box, you can hookup another 4 inch, but make sure to go with s-series so you dont end up with 2 controllers when you only need the one. Not sure but i thi k you could also hookup an s-series 6 inch to thst same box if you wanted to later. Then use the 4inch for intake and 6inch for exhaust?
Sorry, bit I'm way ahead of myself. What size is your grow room? Any idea what the ambient temp of the area around the room and outside is?

AlaskaRob said:

4 inch fan for a 4x4?! I love ac infinity but that just seems way too small. Glad you got the t4 versiin though. With that control box, you can hookup another 4 inch, but make sure to go with s-series so you dont end up with 2 controllers when you only need the one. Not sure but i thi k you could also hookup an s-series 6 inch to thst same box if you wanted to later. Then use the 4inch for intake and 6inch for exhaust?
Sorry, bit I'm way ahead of myself. What size is your grow room? Any idea what the ambient temp of the area around the room and outside is?

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i was asking what size is your grow room XD. mine is 4x4x6.7' gorilla grow tent lite line no extension. temp in the room last i checked without an exhaust is about 83-84F. fairly high i didn't read the RH. in my old grow room ( bedroom closet ) temps were not far off around 80-82F.

i was afraid the 4" fan would be too small but i didn't want to opt for the 6" which i think is 350cfm. the t4 is 205cfm. when i did the math 4x4x6.7 = 107.2 cubic feet /3minutes= 35.73 cfm needed for the room alone then it stated 40% for hot and humid conditions = 14.3cfm+35.73cfm= 50cfm then it stated for hot lights which i also took into consideration even though i run LED's was another 5% so i figured maybe it comes to around 60cfm's so initially it should be more then enough to drop my temps.

i have NO idea though i looked around the forumlas are all the same. idk how accurate these forumla's are but hopefully the 205cfm will be enough. i do have HLG QB's coming in i think they will run cooler then my current King Plus 2000W lights which although has fans on it they do run kind of hot as well. i am not running a carbon filter so no energy wasted there. if anything yea i will run a s6. idk if i can hook up a s6 with a t4 i looked up at the diagrams and it only stated you can run 2 of the same models to the same controls. so i'd have to buy an s4 and hook it up.

i do need to drop my temps more heavily though during flowering otherwise during veg it is more on the good side.

If you can swing it get the bigger fan and turn it down. It’ll be quieter and you can always turn it up on hot days

4x4x6.7=107.2? And then you lose something like 25% with a carbon filter, so add another 26.8 added to the 107.2 is 134cubic ft every minute if you size the fan according to that. Then just to account for variables like heat and humidity, I just figure add another 50% or so. That makes it around 200cfm.
But remember that that is also at max speed, right?
I know, I know. I do odd math. Lol
My tent is 5x5xjust over 6.5ft, so I went with 5x5x6.7=162.5
Instead of all thst adding different percentages, I just doubled it and figured I'd be running at 75% of max. Lol
I went with the t6, but with ambient temps outside my tent at 73 regularly, and summer coming.....i may have to add another fan, but with a t6 I can easily add a s6 to the mix. Still a damn good testament to the brand tho that it keeps my inside tent temps only a few degrees higher than the ambient temp when using my 630w cmh.

Yep. In short, what he said

AND yes, I thi k you are correct in that you can only add another of the same diameter fan with your t4

Sorry, I'm alternating between peach crown and Jamison tonight. Lol

AlaskaRob said:

4x4x6.7=107.2? And then you lose something like 25% with a carbon filter, so add another 26.8 added to the 107.2 is 134cubic ft every minute if you size the fan according to that. Then just to account for variables like heat and humidity, I just figure add another 50% or so. That makes it around 200cfm.
But remember that that is also at max speed, right?
I know, I know. I do odd math. Lol
My tent is 5x5xjust over 6.5ft, so I went with 5x5x6.7=162.5
Instead of all thst adding different percentages, I just doubled it and figured I'd be running at 75% of max. Lol
I went with the t6, but with ambient temps outside my tent at 73 regularly, and summer coming.....i may have to add another fan, but with a t6 I can easily add a s6 to the mix. Still a damn good testament to the brand tho that it keeps my inside tent temps only a few degrees higher than the ambient temp when using my 630w cmh.

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the percentages it said to add was for the CFM not the CF. the 107.2 is CF at least that is what i got from the guide i was following. i'll try and dig up the site in a minute

https://www.htgsupply.com/informationcenter/resources/understanding-ventilation

of fuck yea i did it wrong XD well fuck me.. let me try and recalculate my math now

NVM i did the math correctly so yea it will only hit 50cfm total if i took into consideration the 40% for heat and humidity it claims add around maybe 10cfm or so for the light heat 205cfm should be more then enough to drop temps. this is all just my theory basing on these calculations though i have no idea how it will turn out in the end but as you stated my biggest guess is that the 4" fan is going to be too weak.

i had something like this with aquariums but instead of a fan it's a pump and measure GPH. pumps measure GPH like the fans measure CFM. same rules apply you want to push out more GPH per tank for better filtration but in our case it is air circulation. GPH doesn't drop your temps or nothing it's purely just for filtration needs. however like with fans the stronger your GPH and smaller your tank is the more pressure is built thus more suction in which case can be detrimental for live stock.

on my 55 gal aquarium i run a i think it is 306gph flow is actually steady. there are slight dead spots due to the tank being long but also like the growing hobby we have fans as well to push around air to remove dead spots

Haha you measured how to move the air of the floor of your tent up to a foot off the floor? Ok, yep I'm drunk. Have to sleep.

If you have a 4x4 that wouldnt be filled with plans then get a 4". If you plan on growing a lot of plants then get a 6" because you'll want the extra pull and surface area on the carbon filter.