Air circulation?

When I first hooked up my 600w light it was way too hot for my grow area(getting heats in excess of 100F) but my grow area only had a single oscillating fan. I now have a muffin fan(http://www.skycraftsurplus.com/productimages3/sk1986.jpg) and I'm going to hook that to some ducting and have it run out my window(basically just vacuum sucking the heat out of there and out my window).

My question is where would I be best off to put the fan in order to get the most heat out? Like, behind the light or in front of it, below it(not blocking the plants but so the air flow passes below the light)?

I assume you have an open hood? I do as well.

Anywhere above the light should be fine. the hot air naturally moves up. then focus abother fan at your canopy

During seedling, you can use your secondary fan to further cool the bulb, then hit the canopy when there is one Lol

You want to put your inline fan on the exhaust side of your hood so it draws air through. They are much more effective drawing air instead of blowing. She can suck better than she can blow. Just sayin...:

I do have an open hood(reflector).
For just having the one fan I want to pull heat from the source if I can and since heat rises I guess below the bulb is a no brainer as being a bad idea. Since it's an open hood there is no "exhaust side".
The red circles are where I was thinking of setting up the fan.

Xephier said:

I do have an open hood(reflector).
For just having the one fan I want to pull heat from the source if I can and since heat rises I guess below the bulb is a no brainer as being a bad idea. Since it's an open hood there is no "exhaust side".
The red circles are where I was thinking of setting up the fan.
View attachment 3397726

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Why don't you try to get a decent sealed hood from craigslist that has minimal use? If you have heat issues as bad as you are saying, it doesn't matter how many fans you get, or where you put them, they are not going to work. If your room is sealed, you could try putting a duct port in a top corner somewhere and use that to draw the heat out. If not, you are wasting your time and will never get your temps down.

Mad_Prophessor said:

Why don't you try to get a decent sealed hood from craigslist that has minimal use? If you have heat issues as bad as you are saying, it doesn't matter how many fans you get, or where you put them, they are not going to work. If your room is sealed, you could try putting a duct port in a top corner somewhere and use that to draw the heat out. If not, you are wasting your time and will never get your temps down.

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Actually the room isn't sealed but it is a closet with sliding doors and I'm going to have it all sealed for light leaks so it'll be relatively sealed though not completely sealed. I do plan to have the duct come from the top corner.

I have a piece of cardboard that I am going to put the ducting through and seal off that hole and there's about a 6X6 inch hole down below for the intake.

As for the sealed hood thing, 2 points on that, A: it reduces light to plants about 10%(so I've heard) and B: costs money. I'm not exactly going cheap on this but I've already spent between 600-900ish on this and won't get any back for 4-5 months or so, so I've gotta work on minimizing my costs for now.

Xephier said:

Actually the room isn't sealed but it is a closet with sliding doors and I'm going to have it all sealed for light leaks so it'll be relatively sealed though not completely sealed. I do plan to have the duct come from the top corner.View attachment 3397765

I have a piece of cardboard that I am going to put the ducting through and seal off that hole and there's about a 6X6 inch hole down below for the intake.

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That will help, but I would highly recommend you start checking craigslist (or ebay) for a sealed hood that is used. As long as the glass and the reflectors are not fucked up, any used hood will be fine. The most important part of the sealed hood is the ability to draw that warm (contained) air out of the room before it can go into it. I even take it a step further for my hoods and have jackets on them. The jackets lower the ambient temps on an extreme level. Virtually no heat leaves the hoods except through the ducting. Take a look how I have one of my tents setup. They are all identical to each other. BTW the clear ducting between hoods is key to eliminating the "dark" spot between them.

That fan doesn't look near big enough to cool a 600 watt light. You need to buy the right equipment. How many cfm is that fan? It's also fighting the fact that you probably don't have anything more than a passive intake. Your grow will not be successful with that little air exchange and temps in high 80s

Yea, Im thinking that the closet needs to be treated the same as a tent. This was my thoughts then I found this pic on google. Its got to inline fans sucking air out from top, one on side and one in back. And one inline blowing fresh air in from the bottom.

gardengardian7 said:

Yea, Im thinking that the closet needs to be treated the same as a tent. This was my thoughts then I found this pic on google. Its got to inline fans sucking air out from top, one on side and one in back. And one inline blowing fresh air in from the bottom.View attachment 3397794

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All fans on outside...

gardengardian7 said:

Yea, Im thinking that the closet needs to be treated the same as a tent. This was my thoughts then I found this pic on google. Its got to inline fans sucking air out from top, one on side and one in back. And one inline blowing fresh air in from the bottom.View attachment 3397794

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That is fucked! Keep it simple. One in and one out. Try not to have bends in the ducting as much as possible. That hanging fan in the pic is cutting down on the effectiveness of the fans airflow abilities.

It could be setup that one is for the hood(s) and one for a carbon. The booster fan is the funny part tho.

Yea, See im using cfl... in 4*6*2 and if i was to choose mh/hps 600 in this small unit, my choice would be like the pic I just posted. But I just put that up to show an example. I dont think neither of the pics are bad ideas though. Its whats working for both individual growers. Good ideas i think for both. But of course watts, space, and surroundings are important factors. Like my place all brick so aroma, scent, smell no issue or the need for a scrubber. You know what i mean....

markymark88 said:

That fan doesn't look near big enough to cool a 600 watt light. You need to buy the right equipment. How many cfm is that fan? It's also fighting the fact that you probably don't have anything more than a passive intake. Your grow will not be successful with that little air exchange and temps in high 80s

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By passive intake I guess you mean no fan on it and ya that's the case but as air is sucked out of the room then more air should be drawn in even with a passive intake. It needs to take in as much air as what's removed or it'd implode, lol.

For the record my next grow is going to be much more professional. I'm just trying to build a bit of a bank-roll with this one then I can "grow" my operation. Also side note, vinyl ducting fucking stinks.. I've been airing it by my window and it's like smelling paint.

I'm well aware of what would happen but you don't think that affects the cfms of that fan. Not only is it undersized but it's sucking against pressure. You only see people with small cfl cabinets using those fans. No one is running an open 600 watt hood with a glorified computer fan for their only air exchange... it won't work unless your growing in a very very cold basement.

markymark88 said:

I'm well aware of what would happen but you don't think that affects the cfms of that fan. Not only is it undersized but it's sucking against pressure. You only see people with small cfl cabinets using those fans. No one is running an open 600 watt hood with a glorified computer fan for their only air exchange... it won't work unless your growing in a very very cold basement.

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Honestly I'm hoping I can make it work for a few weeks or so, not a permanent solution. If this does not work well for keeping the room temps manageable then I will be getting a centrifugal fan when I get my carbon filter. If this does not even work to keep the temps below 90 then I will be getting that cent fan sooner than I'd like but I'm trying to spread the costs over time a bit so as to mitigate the dmg on my CC's.

I just looked up the specs on my fan and it's about 105 CFM. That's not bad for being a glorified computer fan. I see there's 4 inch centrifugal fans that are 171 CFM. the 6 inch one is about 435. Either way it's a good fan for 24$. I am debating on getting another one for the intake but that will depend on if this one is close to capable of keeping the temps in check.

Mad_Prophessor said:

That will help, but I would highly recommend you start checking craigslist (or ebay) for a sealed hood that is used. As long as the glass and the reflectors are not fucked up, any used hood will be fine. The most important part of the sealed hood is the ability to draw that warm (contained) air out of the room before it can go into it. I even take it a step further for my hoods and have jackets on them. The jackets lower the ambient temps on an extreme level. Virtually no heat leaves the hoods except through the ducting. Take a look how I have one of my tents setup. They are all identical to each other. BTW the clear ducting between hoods is key to eliminating the "dark" spot between them. View attachment 3397769

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Omg, where can I buy that?

mr sunshine said:

Omg, where can I buy that?

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Which are asking about? The jackets or the ducting?

Mad_Prophessor said:

Which are asking about? The jackets or the ducting?

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Jackets..I use insulated ducting.

mr sunshine said:

Jackets..I use insulated ducting.

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Insulated ducting is wasted between the hoods and is only good for the intake side to keep the condensation down. I bought my jackets off ebay, but the seller has fallen off. If you do a search for "Sun Shield Reflector Cover for Blockbuster 6" you should find a couple sources. Check them close though as some (like mine) have the IR blocker and some don't.

Mad_Prophessor said:

Insulated ducting is wasted between the hoods and is only good for the intake side to keep the condensation down. I bought my jackets off ebay, but the seller has fallen off. If you do a search for "Sun Shield Reflector Cover for Blockbuster 6" you should find a couple sources. Check them close though as some (like mine) have the IR blocker and some don't.

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Cool thank you bro...I only have one 1000 watt the ducting runs through the light straight out the tent ...I usually set mine up the way your's is but not till the summer.. I eliminate the extra fan when possible.


Edit:I never physically threw the light out of my tent. .