Grow Tent Heat Issues

[Mercilus]

Hey everyone,

Im working with a 4.5 x 9.3 grow tent.
Currently I have 2 1000 watt HPS bulbs air cooled by 6" ducting being vented out of the room by a 6" Vortex Fan.

I then have a 4" valueline fan blowing air via scrubber out of the tent creating a vaccuum and pulling fresh ambient air from the room.

I was only recently using 1x1000 watter and my temps stayed okay around 78. I kicked on the other one and its getting a little toasty..(Low 90's).

I also have a fan blowing cold air from the outside into the room to lower ambient room temps.

So I need to rework this to lower the temps even more because its cold outside and im having issues.... so when it warms up i can only imagine.

Anyone have any recomendations on the best way to cool this tent? I also have a 6" valuline fan not in use that I may have to find a use for.

So my one thought was this;

Pull air directly from outside and blow it over the lights and into the room. Then scrub the air and blow it out of the room.

Anyone ever experimented and know the most effective way to cool a tent in a sealed room? There really seems to be so many different options I could do.

I am also planning on buying some CO2 in the coming days so I would like to keep that in mind. (THats why I was considering pulling cold air through the lights from outside instead of just ambient room air) in an attempt to keep them cooler and heat up the tent less frequently and need an exhaust to get temps to realistic levels. )

Any advice would be appreciated.

Thanks in advance.

 

[Shcrews]

(THats why I was considering pulling cold air through the lights from outside instead of just ambient room air) in an attempt to keep them cooler

do that^^

u should run the duct from out one side of the tent to the other... use one of your 6" fans to push air in on one end, and the other fan to pull it out on the other end. This will be much more airflow and keep your lights cooler i think..

how do you run co2 in a tent? tank/reg/digi-controller? if so, then just zip it up and close the vents, as long as your temps are below 90.

if no co2, then just bring in outside air like you are already doing...

sorry i have very little experience with grow tents.. I am setting up a 4x4 footer today and hopefully i will learn quick, but definitely you need to close your ducting

 

[Mercilus]

The co2 will be via a tank and controller.

I'll kick both 6" fans on both end an see what happens.

My only concern w pulling air from outside is it won't be cold come summertime but I guess I'll have an ac going then

 

[Norrath]

i have a 4x4 tent with 2 vertical 400w's stacked in cooltubes. i found the same thing, one is turned on, and it runs 78F in a room that's around 70-73. second one turns on, and im now at 94F

im personally using a 6" fan as well, on its low setting, which is still pretty strong/loud. i think it needs to go up to high speed to move more air, so that your heat isnt exponentially cooking what's inside, because you simply cant get the heat out - which is my vote, because i think that's my own problem, and sounds eerily similar, albeit bigger version of my own.

 

[Mercilus]

Yeah, i didnt think I would have this much of an issue though.

When I get the chance I am going to try and using the 6" fan to vent the tent instead of the 4" but I cant imagine it would make that huge of a difference.

 

[Norrath]

4" fans are horrible. i highly dislike because theyre just too darn restricted.

6" is lowest i would use for exhausting, and i thought mine would suffice, i was so wrong, and very wrong in my guesstimates.

94F with 2x lights on, vs 78ish with 1 light on; i didnt think there woul dbe much difference, but apparently the air moving out and passive intake is just not enough movement and it's heating up very radically. must move more air, youll see a big difference. and stationary fans to mix up the air.

 

[2fast4u2]

Notice how many 6" fans im running.

If you want your environment to be dialed, you gotta fork out for fans to do the job. A 4" exhaust fan and I assume passive intake will not work for your setup. I use two Vortex fans to cool the 1000w and another 6" fan to exhaust with another 6" fan pushing.

I can lower my temps to 75F with a plug in thermostat, so all in all, if you wanna keep those temps down, spend some money.

 

[good drown]

2 fans for one air cooled reflector, never seen that before

 

[Tirs]

Running two fans inline won't increase your cfm beyond the rating of highest rated fan it will only help you over come static pressure better.

Considering centrifugals are so good at overcoming static pressure it seems like a waste unless you have an unnecessarily long complicated duct run. If you want to move more volume introduce another duct run.

 

[guest 77721]

Your best bet is to use cool tubes or sealed vented hoods with 160 CFM of airflow for a 20*F rise in exhaust temps per 1000 W light. Duct the intake and exhaust air from outside the room with a single high volume fan. This will remove the majority of the heat from the tent and not allowing it to build up in the room.

With bare bulbs you will need 320 CFM per 1000 watt light for 10*f above ambient and over 640 CFM when the second light is turned on.

I use this chart to determine the real airflow by taking temperature measurements of the growbox and exhaust air temps. This is the only way to tell if the box is working properly.

 

[Mercilus]

Is it ok to pull air from outside thru lights?

Should I filter it so no condensation gets through?

 

[burnedout]

Any update on the Mercilus?