# Big problem with heat - Can anybody help?



## Deeyou (Mar 17, 2008)

My grow area is 4.5 x 4.5 x 6 ft ... I am running 1600 watts under a growzilla dual bulb hood. which can be air coolable as it has a 4" flange.

However, im going to run into huge heat issues and I wanted to run a sealed room with co2.

However, a portable AC is not an option because it will exhaust the co2 levels significantly. . And I can't realy install a mini-split. 

My question is... Can I just run seal the room and cool the hood without installing a room exahust?? pretty much just have a carbon scrubber and exhaust the room air thru the hood and out the room without an intake??

Sorry if im not clear


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## Timmyjg6 (Mar 17, 2008)

I am no pro, but it dose not sound like that would work. The heat would still build up. You should have at least an exhaust vent threw a wall or out the roof into the attic or somewhere. Do you have pics of the room?


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## Deeyou (Mar 17, 2008)

Timmyjg6 said:
			
		

> I am no pro, but it dose not sound like that would work. The heat would still build up. You should have at least an exhaust vent threw a wall or out the roof into the attic or somewhere. Do you have pics of the room?



no not right now... id have to construct vents anyway... but as long as I can keep the ambient temp around 90 with just cooling the hood... the build up will be fine as long as the co2 levels are maintained... not sure how well I can pull that off though with 1600w in such a small space.. I do have the ballasts outside the room to note


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## Growdude (Mar 17, 2008)

2 things, 1600 watts of light is way more than needed for that size space.
Also dont worry about CO2 just get some good exhaust going.

Exhaust the heat from the top of the room to an outside or attic area, if you exhaust into the adjacent room its going to overheat.

Bring cool air in from the bottom of the grow area.


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## Deeyou (Mar 17, 2008)

Growdude said:
			
		

> 2 things, 1600 watts of light is way more than needed for that size space.
> Also dont worry about CO2 just get some good exhaust going.
> 
> Exhaust the heat from the top of the room to an outside or attic area, if you exhaust into the adjacent room its going to overheat.
> ...



Yea I wanted the maximum amount of light recommended.. From my understanding 80w per sq. ft is the max and I went right for that... I have already invested in the co2 tank and solenoid/regulator.. Maybe I'll save it for the next grow. Thanks


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## Timmyjg6 (Mar 17, 2008)

All you need is 5000 lumen's per SF and trust me it would be so much easier if you just got a 600-1000 watt HPS, and 600-1000 watt Metal Halide conversion bulb. Also grab a reflector where you can vent threw it. place a carbon filter at the top of your room and work the duck to go threw your reflector and vent the air right up into the attic. Also have a fan blowing into the room with fresh air, or some how re root your AC to that room. Feed the cool air to the bottom of the plants. Hope i could help....


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## The Hemp Goddess (Mar 25, 2008)

The extra wattage will do nothing for you if you cannot control the heat, which you are not going to be able to do without ventilation.  If the reflectors are air coolable, you need to do this.  You do need a sealed reflector and an adequate fan for this to be effective.  However, if your reflector is glassed, you should not need a carbon filter on your exhaust.  I would also question whether a 4" duct is large enough to handle the heat from 1600w of light.

I am also of the opinion that CO2 in a space this small is a waste of time, effort and money.  A small fan can bring in sufficient fresh air (you NEED this anyway) as to make the addition of CO2 unnecessary.


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## thestandard (Mar 25, 2008)

you need to cycle the air in the room. Seems like over kill with 1600w when u're in such a small space. drop to 6-800 watts and save the $ on an intake and an exhaust! 

miracle cure if u have nowhere to vent .. thru wall fan


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## Cyclops (May 3, 2008)

The Hemp Goddess said:
			
		

> I am also of the opinion that CO2 in a space this small is a waste of time, effort and money. A small fan can bring in sufficient fresh air (you NEED this anyway) as to make the addition of CO2 unnecessary.


Couldn't agree more .... in my opinion CO2 is way over rated.


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## liermam (May 3, 2008)

Triple the size of your growroom. Problem fixed.



Otherwise, drop 1000 watts of light, bring in the conversion bulbs, find an extremely small CO2 resevoir, build an extensive ventilation system, circulate the CO2 at the back of the room, etc.

400w is enough for a 4' x 4' space. Theres no reason 600w wouldn't be more than enough.


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## smokybear (May 3, 2008)

I would say do away with the co2 and just vent. That will solve your heat problems. Just my thoughts. Take care and be safe.


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## jraddude (May 4, 2008)

Hey man, I agree with everybody here. BUT, if you do want to keep it your way, if the temps inside the grow room dont go higher than the 90's AND you keep a GOOD supply of CO2 in there, you wont need to ventilate.  High heat is bad because the plant's enzymes start attaching to O2 instead of CO2.  But if you keep the CO2 concentration high enough, it'll be fine.  Much more dificult than it should be, but fine.


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## Hick (May 4, 2008)

> 400w is enough for a 4' x 4' space.



.......Actually, a 400 is "enough" for about half that space..
  "Recommended"/ideal 5,000 L/P/Sq/ft.. or 50 HID watts P/sq/ft
even at the "minimum" recommendation of 30 W/P/Sq/ft a 400 lacks sufficient lumens in a 16 sq ft area.
 a 400 gives off "about" 45k lumens. Sufficient for "about" 9 sq ft.


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## The Hemp Goddess (May 4, 2008)

jraddude said:
			
		

> Hey man, I agree with everybody here. BUT, if you do want to keep it your way, if the temps inside the grow room dont go higher than the 90's AND you keep a GOOD supply of CO2 in there, you wont need to ventilate.  High heat is bad because the plant's enzymes start attaching to O2 instead of CO2.  But if you keep the CO2 concentration high enough, it'll be fine.  Much more dificult than it should be, but fine.



That's a lot of ifs...I don't think that there is any way to keep a room that size in the low 90s without ventilation, especially if running 1600W.  Many people go into this growing thing without realizing the necessity of good ventilation.


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## Cyclops (May 4, 2008)

The Hemp Goddess said:
			
		

> That's a lot of ifs...I don't think that there is any way to keep a room that size in the low 90s without ventilation, especially if running 1600W. Many people go into this growing thing without realizing the necessity of good ventilation.


The two most important things to address to achieve a good result and are the most commonly neglected .... ventilation and  _temperature around the roots_. 
I find most people check the temperature around the top of their plants, they don't keep in mind that hot air rises so the temperature is hotter the higher in the room you take the reading .... it's around the roots that is most important.  Keep the roots around 24 degree Celsius / 75.2 degree Fahrenheit and you won't go wrong, the temperature above the roots can be as high as 35C / 95F which is actually good, it's more natural and won't hurt the plants.

Of course Nutrients and Bugs also need to be addressed to get a good result but I repeat, ventilation and temperature must be given a high pyroity.


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