why is my grow tent so hot?

[PLUG420]

im currently growing 5 plants under a 4ft 8 lamp 450 watt t5 fixture and its making my tent super hot. i originally had everything in the corner of a spare room with a inline fan sucking air by the lamp and i had 3 oscillating fans aimed at the light as well and temps were at 93f. i put the plants in the tent hooked up the ducting under the light and and put the 3 fans in the tent and temps were even worse 100f and up.when i first picked t5 lighting for my grow one of the deciding factors was the low temp output but it doesn't seem low at all. would getting another inline fan to properly vent the tent drop the temps in the 80's. ive rigged an old ac to cool the tent but it has to stay on as long as the lights on and i get temps in the low 80's witch is good but with the ac running the light and the fans its too much wattage for my situation for me plus the ac is loud when in a room with all the doors shut. any help would be greatly appreciated

 

[habeeb]

because your plants are .. FIRE

some suggestions, but I need answers. thing you need to understand is 450 is alot of heat, no matter what your running. I would pull some of the bulbs, 1 or 2. also could run the lights at night, if your not


whats ambient temp

inline fan size

ducting length

how many vents do you have open in the tent ( for air to pull in )

inline is running out the room correct, or out the "house" , not recirculating ..

 

[PLUG420]

well the ambient temp is around 80f the fan is a 4 inch 165 cfm and the ducting is running into the bottom of the tent by the light and its going outside to fan and then up to the exaust hole in the room so about a foot or so to the fan and then about 7-8 feet up to the exaust hole

 

[PLUG420]

the inline is running out of the house completly and i had a mesh part with a flap i had that open with a fan infront

 

[macamus33]

The first thing I see is you need to lower your ambient temp. to 75-76*F. You can do this by lowering your A/C temp. or installing some kind of A/C system in the room with your grow. I run a 430W HPS aircooled hood in my 3x3 tent. I use a 6" fan and you want your exhaust for the fan to be at the top of the tent. Hot air rises so you want to pull that air out and fresh air from the room should come from the bottom of the tent. Either the air comes in passively through the vents, or you can install a fan to push air into the tent. If you install a fan make sure it is a less CFM rating than your exhaust fan. Also I am not sure what size tent you are running but on my 3x3 I have a 255 CFM fan. My tent stays around 80-82*F max in hottest part of the summer and 78-79*F in winter. These are just some suggestions and you may have already tried them. LOL.

 

[dickcorn]

Like Mac said exhaust fan needs to be on top pulling hot air out. You have to many fans stirring the hot air around in tent to let it rise and vent properly. One below light on low/med should be fine. Ambient temp needs to be lowered as well, it can be difficult to have less then 5-8 degree difference between ambient and tent.

 

[PLUG420]

i have a 35 1/2" x 54" x 84" tent and i have an ac in the room now running right into the tent witch has me at 83 witch is not bad but the ac is loud and there our other people living on the wall of the room im growing in and has to run aslong as the light is on to maintain that temp plus the temps are getting lower here and the ambient is around 76-78 but with the light and no ac the temp goes up too 100 plus. i think maybe if i draw cool air from outside (my lights are on in the dark so it will be cool air) and exaust in the room or i have a vent coming from the furnace in the basememnt i feel a cool draft from it i could pull air from there and exaust outside. i just really dont wanna run the ac because its too loud too much power draw and its a widow unit that i have modified to exaust out the window but it still generates some heat in the ? will adding another inline fan to the bottom then exausting through the top and removing the 2 oscillating fans givie me the same results im currently getting with ac

 

[dickcorn]

Instead of trying to force cool air in you need to find ways to exhaust hot air out. If you have another inline use it to exhaust more air from tent. If ambient is what you say it is constantly you should have no prob keeping it 5-8 degrees above that. With plenty of hot air exhausted out. If its getting hotter because your raising ambient room temp, then you need to find a way to cool or exhaust the room.

 

[PLUG420]

so this is what i have to work with can you please tell me the best configuration or what i need for the best reuslt

1 165 cfm 4" inline fan
25ft 4' ducting
3 oscilating fans
1 exaust vent in the room of the tent
1 return air vent from basement
the tent has 3 spots for ducting in the bottom 2 towards the top 1 on either side and 2 in the ceiling of the tent
i have an ac but i would rather not use it
the ambient right now is 78
how would you set this up and what do i need to add to it to make it work for temps in the low 80s

 

[dickcorn]

Place as much out of tent as possible to help with heat buildup in tent. Suck hot air out of hole in top. If you have a exhaust vent in room exhaust through it. Use one oscillating fan to gently stir air in tent. Open and filter holes on bottom for more airflow/ less work on fan. Should be fine or you need a larger fan extracting the air.

 

[PLUG420]

okay im gonna take your advice and let you know how it goes thanks for the input

 

[PLUG420]

i switched up everything like you said i have the inline sucking air at the top of the tent exhausting straight outside the house i have 3 intake vents open on the bottom of the tent i have some ducting hooked up to the ac blowing air (fan only) from the room into the bottom of the tent and ive got the oscilating fan in there but im still at 88 degrees i dont understand why its 12- 14 degrees over ambient

 

[bombadil.360]

did you say what size is your tent? maybe your tent is too small for so much light?

is your tent next to a wall that gets hit by direct sun-light during the day?

if so, the sun-light will heat the walls and then transfer heat into the tent; and at night it will still do it as it dissipates the accumulated heat.

if your tent is next to such walls, place the tent at least a foot away from any such walls.

good luck!

 

[green_thumb...]

Put your highest cfm fan for exhaust at the very top of your tent amd run it straight outside so all the heat doesnt get recycled in the main room. It will create a negative pressure. If smell is a factor get a carbon filter and a stronger fan.

I run a 600w hps digi ballast and open hood. Ambient temps are 77-82ish ac sometimes and a 6" valuline centrifugal fan and it ducting strait out at about 3/4 throttle on the fan controller and the 4x4x6.5 tent stays maybe 5° over ambiant.

Gotta have sufficient cfm for your heat exhaust, a little more doesnt hurt either.