Tent grow ventilation

[Brayo1978]

Hi guys.
I've got a tent which is 2.4x2x2m
I plan on running 2 600 watt
Lights in 6" air cooled hoods. And for extraction
A 6" rvk max air flow 796m3/h
Will this be enough to cool both lights
Also plan on using a 6" fan and filter
Fan Same max airflow 796m3/h
Will be using will be using 6" fan
For intake.
Plan on running a 12 pot flood and drain iws
System. Also have a a/c to keep room cool.
Cheers guys. Peace!! Brayo!!

 

[Brayo1978]

Any 1 guys all advice welcome.

 

[caljim]

Those fans will move the air, but what air you are replacing it with will be the deciding factor.

If your just moving air around in a bedroom, or other similar space, without conditioning the incoming air chances are you are not going to be happy. Where is the hot air going to?, and where is the replacement air coming from?

 

[Brayo1978]

Hi hot air from hoods going to be vented into
Attic. And I'm going to use 6" fan for in coming
Air.

 

[Brayo1978]

Any advice I would be more than greatfull

 

[TreehouseJ]

This is how I cool my ~1.7x1.7x2.2m tent. I have the squirrel cage set up to exhaust 30 seconds every hour, and the vortex set up to the light cycle timer (obviously). I also have a 5k btu window air conditioner stickin' through the side hooked up to the thermostat in my co2 controller. I would say cut the intake fan, and throw in a smaller fan to exhaust, with a passive intake. Negative pressure is more efficient at removing heat, for whatever reason.

 

[TreehouseJ]

oops, I'm also seeing now, that I didn't convert your cubic meters per hour to cubic feet per minute..

 

[Brayo1978]

I'm new to this I'm lost.

 

[caljim]

In the simplest of terms......Your fans are ok for the job, but your temps are going to be largely dependent on the temprature of air being drawn into your tent.

 

[Brayo1978]

Wot would u suggest to keep the air being
Drawn into tent to keep temps down. Outside
Air? Thank you for your help guys.

 

[Tynehead Tom]

I'm no expert here but i'll tell you what is working for me. It's also important to know, I had never grown in a tent before this past April so learned how to set it up by reading threads here and my own experience over a couple decades or so.

I have a 2M x 2M x 2.4M high tent as well. (6 x 6 x 7feet)
I set it up in a room that is twice the size. 12x 12 x 8 feet... this room is now acting as a "Lung Room" for the tent.
I have 2 passive intakes.... 4inches diameter (100cm) , passive means no intake fans.
the passive vents are at the floor.
My NH940 hortilux hangs vertical in the middle with 9 plants in 3 gallon pots circling the light.
I have a 6" (150cm) diameter , exhaust ducting from middle of tent above bulb out the side of the tent and attached to the center hole of a parabolic reflector which is fixed in place 1.5 feet from ceiling of the tent. Exhaust fan is an inline 450cfm though could maybe be better served with a 650 during the warmer months but the 450 keeps near perfect VPD. (more on this in a minute) My exhaust fan is outside the tent, 5 feet of ducting from parabol center hole to the fan , hanging from the ceiling joist by thick rubber bungee cords to kill the vibration. very quiet now and no risk of hanging it by the tent structure.
I run a small desk top 6" fan inside the tent at the intake end of one of the passive vents to circulate that cool air as it enters the tent.
I run a 14" circular fan pointing straight up at the bulb and shooting the air up into the parabol reflector . This allows some hot air to get evacuated by the exhaust ducting attached at the center hole of the parabol and also creates an even airflow thru the tent, circulating the air in a up and back down motion, moving all the plants with air current and no need for an oscillating fan. It works so perfect.

with 2 x 600w , you may need a bigger fan than 450 but you won't know till you run it.

before you do anything else tho..... I've come to change some of my methods once I learned about Vapor Pressure Deficit. Anyone growing in confined spaces needs to throw out their "big room" methods and rethink things according to VPD.
There is some awesome threads on this that guys have taken time to write out for us all and big props to them for doing so.
tents do better with negative pressure and the biggest thing I learned and was the hardest to accept was deleting a powered intake..... but it works with passive intake and it works very well.

I leave the lung room door open during lights on and vent into the house for the heat in winter but venting to the attic is not bad either
I leave the window open and run my lights at night. closing the window during lights off, closing the lung room door and using a baseboard heater to maintain lights out temps.
very happy with my tent grow now. And I owe it all to the many threads and grow diaries members have shared here.

 

[caljim]

Rereading your 1st post I see that you are cooling the room with an A/C. You should be good to go.

 

[Brayo1978]

Hi thank you. Passive meaning vents at bottom
Of tent.

 

[Brayo1978]

Yeah I was going to cool room using a portable ac.
But also leave window open during lights on. And close during
Lights off

 

[Tynehead Tom]

passive means unpowered. so just open to allow unrestricted airflow. The coolest air in the room will always be at the floor so this seems to typically be where they are located.
Your exhaust fan is actually doing both jobs, intake and exhaust..... and this allows for the negative pressure to develop in the tent (sucking the walls in slightly instead of inflating slightly if you get what I mean)

 

[Tynehead Tom]

Yeah I was going to cool room using a portable ac.
But also leave window open during lights on. And close during
Lights off

you may not need the ac with the outside air , depending on your climate. I try to only run my tent during the months when night time temps stay below 10Celcius. Above that I would need AC to maintain things for sure.

 

[Brayo1978]

Also in treehouse diagram is he running
2 carbon filters one inside tent one out side
Tent. Once again thank you guys for your
Advice.

 

[Brayo1978]

One more thing wot temps are you guys running

 

[TreehouseJ]

Also in treehouse diagram is he running
2 carbon filters one inside tent one out side
Tent. Once again thank you guys for your
Advice.

Yeah. The one inside is there for odor control (and light-proofing), the one on the outside is for protecting the bulbs and tubes from debris. Both lights are also 600w hps.

 

[Tynehead Tom]

I just have a carbon can filter on end of my exhaust run and I cut up a H.EPA filter into discs that I fit on the outside end of my passive intake tubes, with nylon stocking (thanx wifey) and elastic band so I can change them every few weeks. keeps bugs and pathogens from entering the intakes.

I like the idea of extra odour control by using a fan and carbon filter inside the tent as well and might add that to make things a lil easier on the wife's nose hahaha
neighbors aren't a concern for me.