How big of a inline fan will I need to compleatly cool 2 1000w HID's

Hello RIU I had a couple of quick questions I run 2 1000w HID's and have been using a 6" 400 cfm fan to cool them. But that's just not cutting it. In the summer it gets into high 90s so how big of a fan should I use to compleatly cool the lights? cool enough that I can touch the glass and feel no heat. Also is there something I could use that would allow me to use a bigger fan with a smaller duct opening? My hoods have a 6" opening.

you can get a 8" fan then just buy a thing from home depot or menards that will make it smaller I can't think what they are called but they are in the fan section it will covert 8" to 6", where are you pushing the heat outside or into another room? You might need a a/c in the summer, where do you have the fan installed at, like <fan> ---duct tubing --- <hoods> --- <vented outside> is that how it's installed?

ryan1918 said:

you can get a 8" fan then just buy a thing from home depot or menards that will make it smaller I can't think what they are called but they are in the fan section it will covert 8" to 6", where are you pushing the heat outside or into another room? You might need a a/c in the summer, where do you have the fan installed at, like <fan> ---duct tubing --- <hoods> --- <vented outside> is that how it's installed?

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I want to vent it outside and the fan will be pulling the air from a separate room what I'm going for is to have a compleatly sealed room so I can enrich the air with plenty of co2. And also I'm growing in a 4x8 grow tent that sets inside of a 10x10 room. I would like to keep the tent closed but can open up the doors to vent excess heat if nessary.

co2 is a waste of money, don't even bother for what you put in you don't get it back.. the only upside to running co2 is you can run hot/high temps without affecting the plant.

dk how many cfm my fans are but this is how i personally run themi the summer. I pull air from a lung room that has fresh air access this only goes through the lights. i put a fan infront of the lights and after the lights and exhaust it outside. that way it isn't pulling smell through and the room stays sealed. I also have a 8 inch hooked to a filter that I hung on the ceiling and exhaust that outside but still keeps the room sealed for the most part. In the winter i pull fresh air into the room and have to set timers to keep it warm enough. in the summer i use air conditioners and keep the room sealed 90 percent of the time except when i exhaust. in the summer you will need ac anyway around it. the key is to make sure the hot air leaves the room and anywhere that pulls in air

ryan1918 said:

you can get a 8" fan then just buy a thing from home depot or menards that will make it smaller I can't think what they are called but they are in the fan section it will covert 8" to 6", where are you pushing the heat outside or into another room? You might need a a/c in the summer, where do you have the fan installed at, like <fan> ---duct tubing --- <hoods> --- <vented outside> is that how it's installed?

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Reducers is the word you're looking for I believe. And that is probably the best option for 2 1k lights with 6" hoods. I think an 8" is probably a good idea, if not necessary for 2k watts.


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If you can push the heat elsewhere like another room

kmog33 said:

Reducers is the word you're looking for I believe. And that is probably the best option for 2 1k lights with 6" hoods. I think an 8" is probably a good idea, if not necessary for 2k watts.


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Yeah that's what they are called, is it possible to lower your overall temps of the room itself like turn off the furnace? I don't ever run into heat problems because I have a michigan basement and even if I run a few 1000's I am still under 75

hey get this fan . it works very well . I use them for 2 years and throw them out working . some of them run 24/7 some 12/12

http://www.harborfreight.com/catalogsearch/result?q=ventulator+
it will be enough to cool 4 1000 . if you split it into two rows . it has a high and low . how noisy is it . with the door shut you hear it slightly with tv off . not the if you need it super stealth its not for you . but again you have to run other fans 24/7 so its going to be a bit loud no matter what .

A 6in is just barely enough for a single 1k for me

bryan oconner said:

hey get this fan . it works very well . I use them for 2 years and throw them out working . some of them run 24/7 some 12/12

http://www.harborfreight.com/catalogsearch/result?q=ventulator+
it will be enough to cool 4 1000 . if you split it into two rows . it has a high and low . how noisy is it . with the door shut you hear it slightly with tv off . not the if you need it super stealth its not for you . but again you have to run other fans 24/7 so its going to be a bit loud no matter what .

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Thanks for the tip Do you know what the cfm rating on the fan is?

ryan1918 said:

co2 is a waste of money, don't even bother for what you put in you don't get it back.. the only upside to running co2 is you can run hot/high temps without affecting the plant.

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Don't even bother explaining this to people. They forget there is this thing called an atmosphere an it is huge and vast all around us 24/7 and supplies all the CO2 you will ever need, but I guess they think there is some machine underground making CO2 for the plants int he world--woo woo conspiracy stuff. Silly crap! Then they forget that even if you were trying to enhance it with CO2 he is extracting all the air out of his room all the time so a complete waste as it will go bye bye into the atmosphere for a tree to use. The only way anyone could take advantage of CO2 enrichment would be to have a multi million dollar clean room with sensors everywhere to monitor it and release it by some computer program, which no one here has the money to do in the first place.

twistedwords said:

Don't even bother explaining this to people. They forget there is this thing called an atmosphere an it is huge and vast all around us 24/7 and supplies all the CO2 you will ever need, but I guess they think there is some machine underground making CO2 for the plants int he world--woo woo conspiracy stuff. Silly crap! Then they forget that even if you were trying to enhance it with CO2 he is extracting all the air out of his room all the time so a complete waste as it will go bye bye into the atmosphere for a tree to use. The only way anyone could take advantage of CO2 enrichment would be to have a multi million dollar clean room with sensors everywhere to monitor it and release it by some computer program, which no one here has the money to do in the first place.

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I read the only reason to use CO2 is in a sealed room and you shouldn't have had any neut issues, plants must have been under razer sharp conditions without any issues and then in the last few weeks of flower, you crank the CO2 up.

I think using co2 is a matter of personal preference don't knock it till you've tried it. It can be especially useful in hot and humid grow rooms check out this guys room here he uses co2 and runs his temps at 84f and 75% humidity through the whole grow when the lights are on and he's killin it. https://www.icmag.com/ic/showthread.php?t=300255&do=filter&fid=430341

And after all co2 enrichment has been used in commercial greenhouses for more than 30 years. Some study's have shown plants in co2 enriched environments do grow faster.

AZgreenthumb said:

I think using co2 is a matter of personal preference don't knock it till you've tried it. It can be especially useful in hot and humid grow rooms check out this guys room here he uses co2 and runs his temps at 84f and 75% humidity through the whole grow when the lights are on and he's killin it. https://www.icmag.com/ic/showthread.php?t=300255&do=filter&fid=430341

And after all co2 enrichment has been used in commercial greenhouses for more than 30 years. Some study's have shown plants in co2 enriched environments do grow faster.

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If anything it sounds better than a cold room with AC.

twistedwords said:

Don't even bother explaining this to people. They forget there is this thing called an atmosphere an it is huge and vast all around us 24/7 and supplies all the CO2 you will ever need, but I guess they think there is some machine underground making CO2 for the plants int he world--woo woo conspiracy stuff. Silly crap! Then they forget that even if you were trying to enhance it with CO2 he is extracting all the air out of his room all the time so a complete waste as it will go bye bye into the atmosphere for a tree to use. The only way anyone could take advantage of CO2 enrichment would be to have a multi million dollar clean room with sensors everywhere to monitor it and release it by some computer program, which no one here has the money to do in the first place.

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Lots of growers with sealed rooms use CO2. It's pretty much needed if running a sealed room due to higher than normal oxygen levels from plants. Million dollar controls and clean room is not required to get the benefit of higher CO2 content. You should actually read a few journals where it's used, you'll be impressed maybe.

Budley Doright said:

Lots of growers with sealed rooms use CO2. It's pretty much needed if running a sealed room due to higher than normal oxygen levels from plants. Million dollar controls and clean room is not required to get the benefit of higher CO2 content. You should actually read a few journals where it's used, you'll be impressed maybe.

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Been at this for 35 years kid. You don't need sealed rooms and you sure as hell don't need CO2 enrichment in your room. Ever hear of ducting from the outside of your grow room, you know from the air and before that you have pollen filters so no pollen or dust come in. Oh and here is something else for you sparky, you get that nice cold winter air to keep your temps down, oh and one more thing dummy in the winter time there is 3 times more CO2 in the air because all your surrounding trees and plant are either dead or hibernating, you didn't know that so keep smoking more pot and reading forums, it is also why you get colds in the winter do to the increase of CO2. Now go learn about botany and environments, you don't have a clue. You were in your diapers when people like me were doing all this stuff long ago. You people are funny to watch as you think you are going to control the plant when the plant is in control, not you!

^^^^37 years of growing...... youngster lol. And did I say it's needed? Nope didn't lol. Just said lots do it quite successfully with a sealed room and yup without spending a million dollars lol. Actually I don't run CO2 but know that it works and works well. Dummy ...... Well that's nice lol. It's not about needing it, it's about raising the game up a notch and getting the most out of your room because yes if done properly it does increase yields substantially.... That's botany!!! Have you recently had a stroke? You seem to have a hard time comprehending things. You really should read some of the newer stuff, the original grow bible is kind of outdated lol. I have yet to see you offer any useful information other than ranting about how everyone is doing it wrong. I would love to see some of your work ..... Oh right can't see any cause you've locked your posts......hmmmm. Million dollar clean room you say .... Wow you again humour me with your wisdom. Stop telling people your old, your giving us old guys a bad rep .

Oh and thank you for the science lesson. You've been googling haven't you .

Beauty argument but maybe some one can tell me about something if I'm useing a ac unit in my room isn't it going to vent stinky flower smell out side and referring my carbon filer on my intake useless ?

AZgreenthumb said:

Hello RIU I had a couple of quick questions I run 2 1000w HID's and have been using a 6" 400 cfm fan to cool them. But that's just not cutting it. In the summer it gets into high 90s so how big of a fan should I use to compleatly cool the lights? cool enough that I can touch the glass and feel no heat. Also is there something I could use that would allow me to use a bigger fan with a smaller duct opening? My hoods have a 6" opening.

Click to expand...

In the hot summer months your inline fan will only cool temps to a certain point. I would even use the word cool, more like less hot. I have a 6" fan with carbon filter blowing through 4 hoods all on 750w. Ive managed to keep temps in the low to mid 80s because I'm in a basement...but its getting really hot up here in new england and I have hit 90° in the grow room. So I went out and bought a window unit a/c and built up a box in the back of the a/c to enclose the back of a/c. Cut a 6" hole in box thats connected to ducting and booster fan sucking the hot air out ac box to and out of basement window. I might actually grab a 8 or 10" inline fan and reduce down to 6". I'm sure someone already said this but yes, what you want is called a reducer so you could run a 8" fan to your 6" ducting and hoods. Good luck dude, summer is tough for growing. A/C is a must, I feel. I've gotten away with no a/c for a while but realized it must be done to get optimum results . I'm actually going down to finish up the box and get my a/c cranking in grow room as we speak . Also add a booster fan blowing into your grow room to get some more air flowing in there, also add a few oscillating fans. Best things to do when temps are high is to have humidity in check and have proper air flow. Good luck and stay cool!