400W Tent Grow - How much heat am I gonna be dealing with?

jonnynobody

Well-Known Member
I'm in the process of exploring my setup options for a future tent grow and my concern is the dissipation of the heat from my light due to my apartment situation and the obvious inability to dissipate the heat through an attic / crawl space / window.

My plan is to have a glass enclosed hood w/2 S&P TD125's which will handle the cooling of my light but I have no idea how much heat I'm going to be evacuating from my tent with a 400w bulb blazing for 12 hours a night. I have no option but to evacuate the heat w/ insulated ducting into the bedroom that will house the tent but my b/r door will remain open at night so air flow / room temp should be easily controlled as long as I don't over do it on the light wattage.

Ultimately, my question is: Is should I go with a 400w or a 600w? My intention is to run the lights at night when it's much cooler out and I can leave my bedroom door open to dissipate the heat and I do have good air conditioning in my apt. but I don't want so much heat coming out of those inline fans that my a/c is constantly running.

So what do ya think fellas; 400w or 600w? BTW, this is just a personal medical grow so I'm not looking for multiple LB's out of a harvest or anything crazy like that but I do want to maximize the potential of my tent as the 400 & 600w lights / ballasts are about the same price.
 

jonnynobody

Well-Known Member
well i can tell you my 400 watt tent will get to 110F with no ventilation
That's a given. Proper ventilation is a requirement when growing in an enclosed environment. Hell my apartment gets up to 85 in the dead of summer with the windows open and no a/c on.
 

bigjayb

Member
My very first grow had a 400w hps n that muda f**** burnt. I had it in a closet/wardrobe with sum big fan that sounded like a hovercraft another oscillating fan and a fan directly on the light
had to have the doors open otherwise temps would get in the high 90's temps still rises to the low 90's with the doors open on a summers day but i live in a warm house and the closet was made from solid oak so that made heart a bit worse never again without a real ventilation system let me tell you that walking into the room was like a Rain Forrest and 400w isn't that big but its decent :)

right enough of the story hmmmm as long as you can vent the air outside the tent and have a fresh air supply coming in i don't think i can see any problems m8 i am running a 250w in the same wardrobe/closet from my story <-------- with a 4" extractor fan + carbon filter and a clip on oscillating desk fan temps barely rise above 74 and your going to be using a tent so i can see you getting away with it my wardrobe holds heat more and i vent into the bedroom and doing a fine job :) just keep a window open or 2
 

dwc rebel

Member
I'm in the process of exploring my setup options for a future tent grow and my concern is the dissipation of the heat from my light due to my apartment situation and the obvious inability to dissipate the heat through an attic / crawl space / window.

My plan is to have a glass enclosed hood w/2 S&P TD125's which will handle the cooling of my light but I have no idea how much heat I'm going to be evacuating from my tent with a 400w bulb blazing for 12 hours a night. I have no option but to evacuate the heat w/ insulated ducting into the bedroom that will house the tent but my b/r door will remain open at night so air flow / room temp should be easily controlled as long as I don't over do it on the light wattage.

Ultimately, my question is: Is should I go with a 400w or a 600w? My intention is to run the lights at night when it's much cooler out and I can leave my bedroom door open to dissipate the heat and I do have good air conditioning in my apt. but I don't want so much heat coming out of those inline fans that my a/c is constantly running.

So what do ya think fellas; 400w or 600w? BTW, this is just a personal medical grow so I'm not looking for multiple LB's out of a harvest or anything crazy like that but I do want to maximize the potential of my tent as the 400 & 600w lights / ballasts are about the same price.
hey MI grower i have a 2x4x5 tent with a 400w cool tube 425cfm fan with fan speed controller. runs about 5 to 10 degrees higher than th room it is in. but it will run cooler if you can run the exhaust out of the room.
 

moneytalks420

Active Member
i use 400w and i have a 6 1/2 foot tall tent. it is in my spare room. with no a/c. i use 2 fans inside my tent and i leave the vent holes open and i take off the side patch. my temps dont get any higher than 85. if i wanted it to be cooler i would shut the door and put my a/c in the room. but it isnt a problem. im in flowering too so lets say you are on hour 8 of 12-12 it will be about 84 degrees.... by then the next 4 hours will go by and temps wont rise that much unless you tent is sealed up (which idk why it would be during the light cycle)
 

jonnynobody

Well-Known Member
I think I'm sold on a 250w-er as I think the 400 may become too much to cool as I am in an apt., I need everything very quiet. I'm really only interested in growing 2-4 plants to maturity as I weed out the undesirables in the veg stage so I think the 250 will be a-ok but gosh would I love to put a 400w-er in there but it would require too much ventilation power which would make my stealth grow not so stealth.
 

jimmy1life

Well-Known Member
I use a 400w with one 4in 200cfm fan with the tallboys 20x4 filter too. It it blows threw my cooltube and out my DIY zipper door. In my closet that's 3x4. Must have negitive air pressure that's key. I tried fans every which way till this setup. I just keep my room it self bout 75, and its been treating me good.
You have my vote on the 400
 

PixiDustr

Active Member
I run a 400w and pull air through a carbon filter through my light and out the top of the 4 x 4 tent with an outtake fan of 265 cfm. I also have a clip on oscillating fan that blows across the canopy and a little 65cfm fresh air intake fan. I have a negative pressure and the temps have not been a problem.
 

jimmy1life

Well-Known Member
Nice yes I also have fan a honey 3 speed one not sure what's called 20$ one from wallmart blowing over my canopy and a 4in cheap O under the canopy. Might look into intake but I got piece ducting in the bottom with nylons over it 4 intake. Passive intake there's what looking for. My favorite bulb is hilux might get that 3000k mh bulb in future.
 

Southtexasman87

Active Member
Im in south tex an I have a tent 1.5x1.5x4.5 and a 150w in it and it has a cool hood set up with a DIY fan pulling air thro a carbon filter and I can't get the dame thing to stay under 85 I'm trying it at nite for flower and I have like an 8" honey 3speed fan blowing on the 150w on high but idk going to b moving soon so hope I can run ac cooler think that's a prob the room temp runs about 78-82And my ladybud doesn't seem to like it

I have one fan on light and one fan pulling air out the tent 2 fans and I have the honey ant the bottom pulling air thro the window vent so 3 fans total the fan on the hood is about 150-200 cfm and the other fan pulling air out idk has a good suction to it
 
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