Ventilation assistance please

I've been preparing to setup my first grow room ever.

I've prepared by reading Jorge Cervantes, Ed Rosenthal, and most of Greg Green's books. I've been reading this forum and others for the better part of the last two months (have plenty of time as I'm disabled.) This included this Ventilation 101 thread elsewhere (Sorry if I shouldn't post links to other forums) https://www.icmag.com/ic/showthread.php?t=112862

The one major issue I've run into is ventilation, and I could use some assistance in answer some questions on how to best do it.

I own my own home
I'll be growing in a 5'x5x'7'11" tent.
The tent will be in a basement bedroom.
I have access to the window in the room.
The dryer is in the next room over, and I could drill through the wall and connect to the dryer vent, but it is 4 inches diameter, and hard to get to.
I'll have 1000w of light.
I'll be using an air-cooled hood.
I have no plans to use CO2 currently.

It seems from my reading that it would be best to have a separate intake and exhaust for the air-cooled lights, and a separate intake and exhaust for the tent itself.

My confusion is two part: Where does my intake/exhaust air come from/go (the window or the room?) Does this change if I'm using an AC during the summer?

The second involves selection of fans for both the lights and the tent. I know I'm should refresh the tent air once every 1-5 minutes, but is 3 minutes optimal? It seems that the calculations including a scrubber only require a simple 100CFM or so, but most 6" fans put out much more. Am I missing something. I'm also not been able to find anything useful along the lines of what CFM and kind of fan to use for cooling down and exhausting my single 1000w.


Thanks in advance for any responses.

Bump. Thanks for any help.

Yep bro im having same issues i got a 4x2x5 tent with a 400w HPS....got a 4' 109cfm ran to a carbon filter on top of tent...but temps run 90-95 about 6" above canopy. Im using passive intake now from the bottom vents on 1 side open and got my fan on other side at top to get hot air but i just need to get more AC to get my ambient room temp down...for a 1000w are you going to air cool it ?

I'm prepared to buy an A/C unit for the room if it is needed.

Thanks for any additional help.

Use a small well built 120+- cfm axial fan for the light( my cooltube is cool to the touch anywhere on it with 68-70*F intake temp) and get a small 4"x12" or 14" carbon filter with a nice 4" vortex fan and a speed controller for even better sound control to take care of scrubbing/exhausting tent air. Keeping the light on its own fan and ducting allows a smaller low wattage axial fan to do what it does best, move lots of air with minimal restriction and do it for 30,000 hrs. No need for a vortex fan on a single light fixture, just a small axial fan and minimal ducting will do the trick.

Peace and Great Grows

Asmallvoice

if heat is an issue, you want to change the air 3-5 times per minute. your tent is 5x5x8= 200cf so 200x3= a 600cfm fan. a filter will reduce the cfm. a 600 may be a little overkill but a fan speed controller would help.

better to have a little bigger fan than one too small.

i think to utilize the air cooled hood the best way would be to have an intake air coming from the basement through the hood and to the outside. then you have a passive intake getting air from the basement and an exhaust near the ceiling to the outside.

you shouldnt need to exchange the tent air 3 times per minute if your air cooled hood is doing its job. i dont use a filter so i will leave that up to someone else for their input.

what are your guys opinion on whether to place the cooling fan before or after the lights?

Im thinking that by putting it before the light, the air will run over the bulb and out of the room, essentially making the bulb cool to touch, allowing for the lights to be closer to the tops of the plants. But almost every ventilation system diagram I have seen has the fan after the light pulling air across instead of pushing it.