1mx1mx2m tent, 250w HPS, cooling help!!!!!

Hi, I just bought a 1x1x2m gro cell tent and have a 250watt HPS/MH light (MH bulb blew like straight away) :sad::sad::sad: was a cheap light tho..... So anyway, I'm just gonna try full HPS grow (hopefully that doesn't blow)

My question here is what size exhaust fan should I need to cool it, I have tried putting my lowryder from outside under it at over a foot away from the light and it basically cooked her and stopped it flowering :wall: tried with week old seedling and cooked them:wall: this wasn't in said tent tho, was in a smallish wardrobe, so wanted to know people's thoughts on fan sizes for the tent before I F my next two seedlings up (berryryder and critical mass)
I also want minimal light leakage thru said fan as it is stealth grow and don't want the wall flickering orange light thru fan lol
Any help is appreciated, I thought the tent would be big enough to not need vent, but it's rather warm in there when the lights been on for a few hrs (tested it without plants inside)

Thanks in adavance
 

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Xiphos

Well-Known Member
Use a fan that can recycle the air every 5 mins. Your tent is approx 54 cu feet so a fan than clears 300CFM should work.

Cool tubes are also effective.

You can add a piece of ducting at 90° to the fan so you can't see the light.
 
Use a fan that can recycle the air every 5 mins. Your tent is approx 54 cu feet so a fan than clears 300CFM should work.

Cool tubes are also effective.

You can add a piece of ducting at 90° to the fan so you can't see the light.
Thanks xiphos that duct idea sounds promising!
 
For one you can't have your top exhaust ports sealed up like that.....where do think all the hot air is going to go?
Where do you think the light would go if they were open..... I said I want no light leakage so having any ports wide open is a pretty stupid idea really.....
 

GreenLogician

Well-Known Member
I have a 80cm x 80 x 180cm tent, with a 400w hps cool tube, 300w led, and 150w cfl all inside - running 12/12, light period during the day to make use of my rooftop solar panels.
I use a 'Phresh Hyperfan' 6 inch model, which is 315cfm on max - but comes with a built-in speed controller.
My air con keeps my bedroom at about 23 degrees C.
With my Hyperfan on max, using my cool tube in my exhaust line, that puts my plant canopy temperature at about 25.5 :)
 
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I have a 80cm x 80 x 180cm tent, with a 400w hps cool tube, 300w led, and 150w cfl all inside.
I use a 'Phresh Hyperfan' 6 inch model, which is 315cfm on max - but comes with a built-in speed controller.
My air con keeps my room at about 23 degrees C.
With my Hyperfan on max, using my cool tube in my exhaust line, that puts my plant canopy temperature at about 25.5 :)
Cheers man, might have to save a lil more $$ to get the proper things I need :) thanks for the help
 

provisionseeds

Well-Known Member
For the correct exhaust and intake fan:

L x W x H = Cubic Feet

Cubic Feet x 25% (resistance) = What CFM you need.

For intake I would always go for the next size down in fan size.


If you have some money, always go bigger then what you really need so you have some room to expand or change later on.
 

itBUDtime

Member
Get any 6in inline fan and a good temp controler set it inside the tent just a few inches below the canopy and suck the air out the tent
 

mtnman2016

Well-Known Member
I have a similar setup 2x2x5.5' and put a 600 Watt dimmable set to 50% so 300 Watt MH and really struggled to get temps under 85 degrees. Installed a 6" exhaust ducted to the top with speed adjusted to 50% and just have 2 4" bottom holes opened. I am still vegging so the light that might come in doesn't matter right now. Temps are now at 75-79. I'll duct a 4" under the house before flowering though to bring in cooler air and cut out light. Will definitely buy an air cooled hood before my next grow.
 
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