Ventilation Question

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Twist1285

Member
I have a 4x4x7 mylar tent. I would like to use a 250w HPS with a cool tube.

My question is....can I leave one end of the cool tube open and have the duct just suck the air from my grow tent and use that to cool the light? Or should I have the intake for the cool tube come from outside of the tent?

I'm wondering if I used say a 6in inline fan to exhuast both the room AND the cool tube would my tent stay cool enough with just passive intake from holes in the tent?

I'd imagine if I used the grow space I would need some sort of dust filter so dust can't reach the bulb? There are about 100 post about this sort of thing, but I just can;t seem to find the exact answer im looking for, so my grow is on hold until I get this going haha
 
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SimplyM1tch

Member
yes u can, you can do it either way if your ueseing co2 though its recomended to cool the tube from the outside of the tent so your not sucking co2 out

but the way your asking is tottaly fine just remember your gonna need a carbon filter on the open end of your cool tube or your neighbors will catch on
 
rasputin71

rasputin71

Well-Known Member
4x4 you should get a 600w at least. I had a 400w in my 3x3 flower room and replaced it with 600w 2 weeks into flower. Need a 400w ballast? :p
 
S

SimplyM1tch

Member
rasputin71 said:
4x4 you should get a 600w at least. I had a 400w in my 3x3 flower room and replaced it with 600w 2 weeks into flower. Need a 400w ballast? :p
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yea thats another thing too i had a 250W my buds came out all fluffy.....so i upgraded to a 1000W and a 90W LED UFO all in the same 4x4x7 mylar tent mmm density
 
T

Twist1285

Member
SimplyM1tch said:
yes u can, you can do it either way if your ueseing co2 though its recomended to cool the tube from the outside of the tent so your not sucking co2 out

but the way your asking is tottaly fine just remember your gonna need a carbon filter on the open end of your cool tube or your neighbors will catch on
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I love this site haha. About the light, I was planning to suppliment with CFLs I have. I have enough reflectors and lights to put another 20k lumens or so to get underneath the foliage. If I were to upgrade to say a 400w would the same system work to control heat? As in just using the tent space as intake to both cool the light AND exhaust the room? or would I then need to add an additional intake? Thanks everyone, obviously new to indoor grows, but catching on quickly with all of your posts.

I'm not using any co2 as of yet, its a bit advanced for me right now.
 
S

SimplyM1tch

Member
I'm running a 1000w in that setup my temps stay 70-85 sucking from inside the tent through a carbon filter...then again I have a 8" vortex but I uese it at half speed most of the time

you should be good with a 250w or 400w as long as you have a good fan
 
N

NateDizity1420

Active Member
the ventilation your describing will work either way, but for a box that size I would have at least a 400w system preferably a 600w system would be your best bet
 
FootClan

FootClan

Well-Known Member
Twist1285 said:
I have a 4x4x7 mylar tent. I would like to use a 250w HPS with a cool tube.

My question is....can I leave one end of the cool tube open and have the duct just suck the air from my grow tent and use that to cool the light? Or should I have the intake for the cool tube come from outside of the tent?

I'm wondering if I used say a 6in inline fan to exhuast both the room AND the cool tube would my tent stay cool enough with just passive intake from holes in the tent?

I'd imagine if I used the grow space I would need some sort of dust filter so dust can't reach the bulb? There are about 100 post about this sort of thing, but I just can;t seem to find the exact answer im looking for, so my grow is on hold until I get this going haha
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everyones right you can do eather or....if you use one fan for exhausting and cooling then your limited to how much you can control the envierment because you now have to have that fan running all the time verse if you had a dedicated fan for the light and one for the exhuast you could control the amount of air you bring in and let out.....you also cant use Co2 if you only use one fan.....I have a 4x4 space with a 1000w and i do what your saying i use one fan to cool the light and at the same time exhaust the air out.....works great for me......I also have a 4x4 tent that i use a 600w in tandom with a 400w and i use a dedicated fan just for cooling and another fan just 4 exhausting.....the room with two fans is able to use c02 and i can control when and how long my exhaust fan comes on verse my other set up where the fan must be on 24/7....

Also 250w in a 4x4 tent?? na that sounds like a waste of time and energy.....if your going to do it then just do it right......get yourself a 600w that will just barely be enough really... heres the facts 1000w= 4x4 600w= 3.5x3.5
400w= 3x3 and last 250w= 2x2 so you can see that a 250w will not be ideal for a 4x4 space.... lil advice here a 400w is about the same price as a 600w so knowing all this you sure you still want a 250w light??

Are you wondering if your tent will get to hot with a 600w or 1000w? good you should be but if your fan is exhausting the hot air OUTside you should be able to keep your temps in check....IF your fan is going to exhaust your hot air anywhere in the visintly of your tent then you will be screwed period...

I use 1000w in a 4x4 and exhausted all air OUTSIDE and my temps are around 78 degrees( about 5 degrees hotter the ambient temps)
 
ataxia

ataxia

Well-Known Member
for sure man a 6 inch inline is plenty of exchange .... i would suggest a bigger light though. a six inch can be used without the cooltube if your only using the air cooled reflector for heat issues on the 250. and if you have to use the open end cooltube. I've heard womens nylons work fine as a dust fiter on the open end. without taking away cfms
 
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Twist1285

Member
Alright.....so here is what I'm gathering. Just go ahead and don't try skimping, which makes sense to me, why buy something that I'l just upgrade in 2 months. So, I'll get a 600w system run the cool tube with a 6in inline fan....intake straight form the grow space and exhaust it OUTSIDE. Passive intake will be fine with this from what you are telling me. I wanted to get this right, I've always been fearful of HPS heat. Sounds like these fans really do the trick though...last poster said I wouldn't even need a cool tube?, but if I'm gonna exhaust the room with the 6in fan I figure why not just use the tube anyhow, then I could put it closer to the plants, I'd imagine.

Thanks again everyone
 
FootClan

FootClan

Well-Known Member
Twist1285 said:
Alright.....so here is what I'm gathering. Just go ahead and don't try skimping, which makes sense to me, why buy something that I'l just upgrade in 2 months. So, I'll get a 600w system run the cool tube with a 6in inline fan....intake straight form the grow space and exhaust it OUTSIDE. Passive intake will be fine with this from what you are telling me. I wanted to get this right, I've always been fearful of HPS heat. Sounds like these fans really do the trick though...last poster said I wouldn't even need a cool tube?, but if I'm gonna exhaust the room with the 6in fan I figure why not just use the tube anyhow, then I could put it closer to the plants, I'd imagine.

Thanks again everyone
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Now your starting to make sense buddy i like what i hear.....u may or may not need the cooltube.....Yes the cooltube keeps things cooler but its not really ideal for the best reflections i think the "daystar" aircooled hood reflectors alot better ....i have cool tubes, daystars..hydra farm hood flectors and wing reflectors. out of everyting i LOVE my daystar the most its got a cylinder like concave inside more like a cooltube but it reflects very well more like a reflector hood....i use the daystar for my 1000w light and i use the cooltube for my 600w light... Now the daystar dosent cool as well as the cooltube but the reflection is WAY better and since my temps are in the 70's with the daystar i dont see the need to switch the cooltube and loose reflection........ I know that you want to make sure your light isnt too hot but dont over do it eather. cool tubes are cool but not always the best way.....if your room is so hot where you HAVE to use a cooltube then do it but if you can use a aircooled hood then do that it will most likely reflect better...plus if you use a 600w you wont have the high temps of a 1000w like i do...also if your exhausting OUTSIDE then even more reason that you wont have heat issues ....so keep that in mind.....in the winter i dont even aircool my 600w because i want that heat to keep the room at proper temps.... make sense?
 
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Twist1285

Member
Awesome, makes alot more sense now. I appreciate everything! The next step I think is to jsut hook this all up and start testing the temps and such. Should give me a better idea of what I'm need to run. I live in FL so its pretty warm here all of the time. My house I keep around 78 or so all the time. Floridians arn't very comfy in less than 70 haha, I may have to block that room off and let the AC cool it down to keep the ambeint temp closer to 74 or so, id imagine that would help with jsut a passive intake.
 
FootClan

FootClan

Well-Known Member
Twist1285 said:
Awesome, makes alot more sense now. I appreciate everything! The next step I think is to jsut hook this all up and start testing the temps and such. Should give me a better idea of what I'm need to run. I live in FL so its pretty warm here all of the time. My house I keep around 78 or so all the time. Floridians arn't very comfy in less than 70 haha, I may have to block that room off and let the AC cool it down to keep the ambeint temp closer to 74 or so, id imagine that would help with jsut a passive intake.
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Even though your temps will be to hot the fact that you say its usually consistant means the problem will be easyer to fix... I live where it gets really hot then really cold so i have to deal with two things...

All you need is a way to bring down the ambient temps in your living area wether that means using your home airconditioner(too expesives and cools to many areas that you dont need cooled).. Or get a portable air conditioner and direct it into your grow area. Those are you best options....Rember though if your exhaust isnt exiting the entire apartment then it will never work....You have to find a way to get that Old hot air OUTSIDE before you do anything....In my aprtment i can acutally get into my attic and acces the ducting that contects to my bathroom fan....I dont use this method because i found a different method utilizing my window frame and a wooden box but going through my attic was next on my list of ways to get that hot air out....

How ever you do it make sure you get that hot air Outside so you can passivly bring in fresh air and create a neagtive pressure for your one your grow space and two your entire aparment not allowing any smell to escape before going through the scrubber..
 
T

Twist1285

Member
FootClan said:
everyones right you can do eather or....if you use one fan for exhausting and cooling then your limited to how much you can control the envierment because you now have to have that fan running all the time verse if you had a dedicated fan for the light and one for the exhuast you could control the amount of air you bring in and let out.....you also cant use Co2 if you only use one fan.....I have a 4x4 space with a 1000w and i do what your saying i use one fan to cool the light and at the same time exhaust the air out.....works great for me......I also have a 4x4 tent that i use a 600w in tandom with a 400w and i use a dedicated fan just for cooling and another fan just 4 exhausting.....the room with two fans is able to use c02 and i can control when and how long my exhaust fan comes on verse my other set up where the fan must be on 24/7....

Also 250w in a 4x4 tent?? na that sounds like a waste of time and energy.....if your going to do it then just do it right......get yourself a 600w that will just barely be enough really... heres the facts 1000w= 4x4 600w= 3.5x3.5
400w= 3x3 and last 250w= 2x2 so you can see that a 250w will not be ideal for a 4x4 space.... lil advice here a 400w is about the same price as a 600w so knowing all this you sure you still want a 250w light??

Are you wondering if your tent will get to hot with a 600w or 1000w? good you should be but if your fan is exhausting the hot air OUTside you should be able to keep your temps in check....IF your fan is going to exhaust your hot air anywhere in the visintly of your tent then you will be screwed period...

I use 1000w in a 4x4 and exhausted all air OUTSIDE and my temps are around 78 degrees( about 5 degrees hotter the ambient temps)
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you should be a lighting sales rep. I started out thinking about TRYING a 150 HPS.....after your pitch I got a 600w HPS hahahaha
 
TheDude0007

TheDude0007

Active Member
All the comments are good.

I have a 400w hps and man do I strugle to keep the temps down. I have been doing beutifully all year and now that it is summer I have one plant die after the other :-( I have 2 fan's on the plants and a big ass extractor that vents out and still I am having major damage.
 
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