extracting heat

Dylanfurlong

Dylanfurlong

Well-Known Member
hi , please could someone give me some advice on my new grow area which is 6meters by 6 meters and 7ft tall . I need to know what type of fan do I need to extract the heat from 6 open 600w hps lights (open reflectors) from this area . would I need a box fan ? would I need multiple fans ? and would my intake fan have to be the same power /size etc
 
Skankstarr

Skankstarr

Member
I just use 6x 425CFM fans for my 6x 1000w"s, my rooms stays between 70-75. I run my lights at night though. I have one fan pumping cold air in and the fans hooked up too the lights pull air out.
If I remember correctly 425CFM per 1000watt
 
Dylanfurlong

Dylanfurlong

Well-Known Member
Skankstarr said:
I just use 6x 425CFM fans for my 6x 1000w"s, my rooms stays between 70-75. I run my lights at night though. I have one fan pumping cold air in and the fans hooked up too the lights pull air out.
If I remember correctly 425CFM per 1000watt
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Do you hook them up to lights as you said? Because I have open reflectors no cool tubes or anything so how would I hook a fan up to them?
 
A

adower

Well-Known Member
Dylanfurlong said:
Do you hook them up to lights as you said? Because I have open reflectors no cool tubes or anything so how would I hook a fan up to them?
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Is your room sealed? If so your only choice is an ac. If open room then it's best to have the fan and filter up high since heat rises. Then route the ducting out of the room to exhaust the heat.

I'd run a passive intake which should be 1.5 times the size of your exhaust.

Unless your hoods are designed to have a duct ran to them you won't be able to hook a fan to them.

Search google on how to size your fan. There is a formula to break everything down
 
ipeeinpools

ipeeinpools

Well-Known Member
Dylanfurlong said:
hi , please could someone give me some advice on my new grow area which is 6meters by 6 meters and 7ft tall . I need to know what type of fan do I need to extract the heat from 6 open 600w hps lights (open reflectors) from this area . would I need a box fan ? would I need multiple fans ? and would my intake fan have to be the same power /size etc
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I have roughly the same size flowering area, running 2315 watts, my hoods are vented and i still use a portable AC and 2 box fans for circulation.

I use a single 8" duct fan for intake, my ac is my echaust. My room stays at about 23 celcius
 
Dylanfurlong

Dylanfurlong

Well-Known Member
Hi again I have 6 of these in the 6mx 6mx 7ft space the room is not airtight it does have little air leaks . I am planing on a big intake and a big outtake but I need to know roughly how big? Or will I need multiple intake and outakes. If I move the hot air quickly enough out will it keep the room at optimised temps
 

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ipeeinpools

ipeeinpools

Well-Known Member
Dylanfurlong said:
Hi again I have 6 of these in the 6mx 6mx 7ft space the room is not airtight it does have little air leaks . I am planing on a big intake and a big outtake but I need to know roughly how big? Or will I need multiple intake and outakes. If I move the hot air quickly enough out will it keep the room at optimised temps
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I would almost bet your going to need an AC....but it all depends I guess how you do your set up, where your getting your intake from, where your dumping your exhaust. with 6 of those reflectors, your creating approx 12K btu's of heat per hour. that's quite a bit to simply exchange. I won't say that it CANT be done but I'd say Id be impressed if you did
 
kratos015

kratos015

Well-Known Member
Dylanfurlong said:
Hi again I have 6 of these in the 6mx 6mx 7ft space the room is not airtight it does have little air leaks . I am planing on a big intake and a big outtake but I need to know roughly how big? Or will I need multiple intake and outakes. If I move the hot air quickly enough out will it keep the room at optimised temps
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Those tents usually have 8 inch ducting vents, for 6 600 watt lights you're going to need at least 2 8 inch inline fans just to remove the heat. If you're growing anywhere where it's over 80 degrees outside, the inline fans are only going to be able to bring your grow down to the ambient temps at best.

I'm running 4 of those same lights, with 2 hooded 1000 watt bulbs. I have 2 15k BTU window air conditioners running just to keep the room at 80-82.

With 3600 watts in open hoods, you're going to be generating 12,600 BTU of heat every hour. This doesn't account for the heat that the rest of your equipment is generating, nor does it account for the room itself, that figure is just for your lights. A quick google search showed that with a 6mx6m room (1m=3ft I believe?) you're at 324sqft which requires a 9k BTU unit alone, again this doesn't include your lights and equipment. A 15k BTU window unit would barely be able to keep up with your tent, seeing as the tent you have isn't perfectly sealed that's going to be another issue.

So, since you'll be needing a 9k unit just for the room alone and your room generates 12,600 in heat from the lights, you'll be needing 22k BTUs of cooling power at a bare minimum.

So we've determined you're going to need around 24k BTUs of cooling power and you have a handful of options as to how to go about this. You can either go with 2 12k units, one on the left and right hand sides of your tent. Or, you can go with 3 9k units strategically placed around the tent to provide even cooling throughout the room. With air conditioning, it's better to have too many than too little. If you have too many you can simply shut one off so things run more efficiently. If you have too little, you're SOL and your yields will suffer greatly.

I made the same mistake with my first indoor grow, barely pulled 2lbs from 2000 watts which is pathetic. I had a single 12k unit at the time and it couldn't ever keep up, and this was before dimmable ballasts so I was fucked.

Not trying to be an ass, but unless you can spring for the air conditioning you may as well shut things down or at the very least shut down half of your lights. Your quality and yields will suffer immensely if you don't get the temps figured out. Don't be like me and lose money because you don't want to spend the money on cooling, I still regret that indoor grow to this day and would hate to see anyone else in the position I was in because of it.
 
Dylanfurlong

Dylanfurlong

Well-Known Member
kratos015 said:
Those tents usually have 8 inch ducting vents, for 6 600 watt lights you're going to need at least 2 8 inch inline fans just to remove the heat. If you're growing anywhere where it's over 80 degrees outside, the inline fans are only going to be able to bring your grow down to the ambient temps at best.

I'm running 4 of those same lights, with 2 hooded 1000 watt bulbs. I have 2 15k BTU window air conditioners running just to keep the room at 80-82.

With 3600 watts in open hoods, you're going to be generating 12,600 BTU of heat every hour. This doesn't account for the heat that the rest of your equipment is generating, nor does it account for the room itself, that figure is just for your lights. A quick google search showed that with a 6mx6m room (1m=3ft I believe?) you're at 324sqft which requires a 9k BTU unit alone, again this doesn't include your lights and equipment. A 15k BTU window unit would barely be able to keep up with your tent, seeing as the tent you have isn't perfectly sealed that's going to be another issue.

So, since you'll be needing a 9k unit just for the room alone and your room generates 12,600 in heat from the lights, you'll be needing 22k BTUs of cooling power at a bare minimum.

So we've determined you're going to need around 24k BTUs of cooling power and you have a handful of options as to how to go about this. You can either go with 2 12k units, one on the left and right hand sides of your tent. Or, you can go with 3 9k units strategically placed around the tent to provide even cooling throughout the room. With air conditioning, it's better to have too many than too little. If you have too many you can simply shut one off so things run more efficiently. If you have too little, you're SOL and your yields will suffer greatly.

I made the same mistake with my first indoor grow, barely pulled 2lbs from 2000 watts which is pathetic. I had a single 12k unit at the time and it couldn't ever keep up, and this was before dimmable ballasts so I was fucked.

Not trying to be an ass, but unless you can spring for the air conditioning you may as well shut things down or at the very least shut down half of your lights. Your quality and yields will suffer immensely if you don't get the temps figured out. Don't be like me and lose money because you don't want to spend the money on cooling, I still regret that indoor grow to this day and would hate to see anyone else in the position I was in because of it.
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thank you very much for that advice , I do not understand air conditioning a lot but by the sounds of it , instead of trying to remove the hot air with fans the air conditioners will bring the temps down automatically? if I have enough them . ?
 
Dylanfurlong

Dylanfurlong

Well-Known Member
I think I am better off buying 6x cool tubes and converting my 6 lights into air cooled ones , but will the cooltube lessen the light or is there any negative comparison barring heat .
 
Carolina Dream'n

Carolina Dream'n

Well-Known Member
18ft by 18ft for 6 600s?
We always did 10x10s for 3600 and it felt too big. That room is gonna be hard to cool without ac because of the ceiling height. With taller ceilings you give the heat somewhere to collect above the lights and plants then be pulled out.
 
Dylanfurlong

Dylanfurlong

Well-Known Member
Carolina Dream'n said:
18ft by 18ft for 6 600s?
We always did 10x10s for 3600 and it felt too big. That room is gonna be hard to cool without ac because of the ceiling height. With taller ceilings you give the heat somewhere to collect above the lights and plants then be pulled out.
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yeah the room is 6 meters long 6 meters wide and 7/8ft tall . do you think there is any fans you can recommend or system to get the hot air out and stay in range of temps without a ac using fan/s
 
Dylanfurlong

Dylanfurlong

Well-Known Member
my intake will be from outside and outtake will be going outside too I just don't want the room going over 30 oc
 
kratos015

kratos015

Well-Known Member
Dylanfurlong said:
thank you very much for that advice , I do not understand air conditioning a lot but by the sounds of it , instead of trying to remove the hot air with fans the air conditioners will bring the temps down automatically? if I have enough them . ?
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Exactly. Any sort of wattage will produce 3.41 BTU of heat for every 1 watt. So each 600 watt light will produce 2100 BTU of heat if it's an open hood, even with a vented hood those lights will still produce around 1000-1100 BTU of heat.

There are two ways to get rid of heat (BTUs), one method is to remove the heat faster than it can generate by using fans. However this is only a viable option if your ambient temps aren't higher than 80 degrees at a time, otherwise you'll still be battling the ambient heat even if you can remove the heat from the lights.

The second method is to cool the room faster than the sources of heat can heat it up.

In your case, your lights give off 12,600 BTU of heat. So in order to eliminate the heat you'll need to produce 12,600 BTU of cooling.. but that is just to eliminate the heat, not cool the room itself. The room itself also requires 9,000 BTU of cooling power. So with the 9k needed for the room, plus the 12,600 of heat, you'll need 21,600 BTU of cooling to keep your room cool. Window units typically come in 6k, 9k, 12k, and 15k and beyond. Since you need roughly 22k BTU, and because your room is so large, you would get more efficient cooling using multiple air conditioners as opposed to a single powerful one. I feel that your best bet would be 3 9k BTU air conditioners. This would provide you with 27,000 BTU of total cooling power and you can place on AC on the left and right sides of the tent and another one in the back of it. You could also get yourself 2 12,000 BTU ACs and place one on the left and right hand sides of the tent. It's much better to have 3 air conditioners spread out through the entire room instead of 2, this way the air conditioners don't have to cool are large of a space. If you went with 2 12ks, then you'd have one for each half of the room. However if you go with 3 9ks then you have 3 air conditioners working 3 different parts of the room, resulting in a more even and efficient cooling.
 
Dylanfurlong

Dylanfurlong

Well-Known Member
this is the most powerfull fan I can find it says 4250 m3 and is 12'' , would this pull hot air out fast enough or do you know any better powerfull ones ? I calculated my area at 10500m3 . it is roughly 5m x5m x 7ft then I multiplied that by 60 , is that correct ?
 

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kratos015

kratos015

Well-Known Member
Dylanfurlong said:
this is the most powerfull fan I can find it says 4250 m3 and is 12'' , would this pull hot air out fast enough or do you know any better powerfull ones ? I calculated my area at 10500m3 . it is roughly 5m x5m x 7ft then I multiplied that by 60 , is that correct ?
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I believe so, but unless you're living somewhere where it's constantly nice out and never above 80 degrees then there's no amount of ventilation that is going to help you cool that room. If you live in a climate where your temps won't be going over 80 degrees for the next few months, then you can get a good ventilation set up going to help you out.

But if you're in a location where summers get hot like I am, there is no amount of ventilation that is going to help you out.

As everyone else has been saying, you pretty much have to get air conditioning if you want this to be remotely possible. The only way you'd be able to get an inline fan to work for you is if you only had one, maybe two lights. If you have to have all 6 lights running then air conditioning is pretty much your only option. Trying to run 6 lights without proper cooling will only bring disaster, trust me I've done it before. The only way ventilation will work is if you're only running 1 or 2 lights, and 1-2 lights with proper ventilation will yield more than 6 lights without cooling. Trust me, without cooling this will pretty much be a no go.
 
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