# Ventilation question (temps too high!)



## webwalker420 (Apr 17, 2008)

Well I got my 400 HPS in today and hooked it up. I have 5 little seedlings poking through the soil now but my temps are too high for my liking. My current grow space is pictured below. I currently have a 110 CFM in ceiling and a 4" ducting coming in from ceiling that is tapped into my AC ducting directly but its too hot still.

Right now I have to keep my door half open to keep temps to around 80, if I close em they shoot up to 85-86 and who knows how much higher as summer hits!!

So here is what I am going to do. I ordered a 290 CFM fan that is only .5 sones louder then my current one and I am going to cut intake holes in my wall between the closet and the room. (bottom, to the right of the door in first pic) 

My grow space is 96 cubic feet, (6x2x8). If I run a 290 CFM fan on the ceiling venting into attic, how large of intake do I need on bottom? I want to make sure I cut the holes big enough but not overkill because I am worried about smell getting out through them and also, I need to figure out a way to light proof em.

Lets here some ideas!!


http://www.marijuanapassion.com/forum/attachment.php?attachmentid=54943&d=1207684518 


http://www.marijuanapassion.com/forum/attachment.php?attachmentid=54944&d=1207684518


----------



## The Hemp Goddess (Apr 17, 2008)

Is the light air cooled?  That makes a huge amount of difference.  I run a 1000W in a 3 x 6.5 x 7.5 closet and I couldn't keep it cool enough without air cooling the light.


----------



## NorCalHal (Apr 17, 2008)

Aircooling your light will bring the temp down big time.

But with the exhaust fan exhausting to the attic, I would put a 4" passive intake from under the house.


----------



## webwalker420 (Apr 18, 2008)

Ok I can't vent from under house, no basement...built right on slab lol.


I have a cool tube sun reflector, I think I am going to try and vent it somehow...


----------



## headband (Apr 18, 2008)

webwalker420 said:
			
		

> I have a cool tube sun reflector, I think I am going to try and vent it somehow...


thats a good idea, or than it would be a hot tube sun reflector, without venting. hahaahaha jusst playing mang:hubba:


----------



## webwalker420 (Apr 18, 2008)

How are you supposed to vent these when you move the light up and down!


----------



## The Hemp Goddess (Apr 18, 2008)

webwalker420 said:
			
		

> How are you supposed to vent these when you move the light up and down!



I have a large air cooled reflector.  I come out of the inlet and outlet with a 90 degree bend pointing up.  There is a short section of dryer duct attached to that, and then I go to hard piping again to get to my inlet and outlet vents.


----------



## Anchral (Apr 19, 2008)

I built my garden in my garage, it looks like a tall work bench with a door, because with my kids all over the house, there really is nowhere else to grow. So, heres my thing, my tall work bench is about 4' tall x 3 1/2' wide x 3'. No ventilation (i read you need to only open the door about once per day for 2 plants to get adequate air) besides, I cant vent the air beacuse the garage will smell like weed and garage temps are way too hot in summer and too cold in winter. I got this air pump with 6 adapters, 35 watt, I think, but the thing is too loud and its generating too much heat. My room is at around 90. I have a fan going all the time but its just not enough. My 1 girl i have in there is almost done and with outside temps getting warmer, I dont know how much more of this she can take. I was wondering about a "space air conditioner" any ideas would be greatly appreciated.


----------



## md.apothecary (Apr 19, 2008)

Well... your intake needs to be about the size of the exhaust. You don't want to have too much negative pressure or else there is not going to be proper ventilation, which seems to be your problem now. If you create a vacuum, you will NOT get proper ventilation. If you have an intake fan that can replace the airflow quick enough, you will get great cross flow, cooler air, and better temps.

Buy a new reflector that uses a glass sheild, if yours does not already, this reduces temps. Or simply reduce the wattage of your light.

I've posted once before in the lights section that 400w is NOT necessarily the best light for just any grow. I started with 400w and it was way too hot even with ventilation. Yield was bad, went to a reduced wattage and yield is higher and temps are MUCH cooler!


----------



## 4u2sm0ke (Apr 19, 2008)

webwalker420 said:
			
		

> How are you supposed to vent these when you move the light up and down!


 
vent out the top of grow box where heat rises...have intake bring in fresh air from outside of house/grow room..and have fan moveing air around inside...post some pics when you can my friend


----------



## webwalker420 (Apr 19, 2008)

check my newest post...."pimp my growroom" for pics


----------



## stunzeed (Apr 27, 2008)

The Hemp Goddess said:
			
		

> Is the light air cooled? That makes a huge amount of difference. I run a 1000W in a 3 x 6.5 x 7.5 closet and I couldn't keep it cool enough without air cooling the light.


 

True air cooling helps when the air you are pulling in is semi cool. When outside temps rise to 90-100 you are gonna have issues again. Especially if it is a totally sealed grow area. Air conditiong is the best solution. Try a small portable unit. They are pretty cheap online. 

Good luck,

Stunzeed..


----------



## md.apothecary (Apr 27, 2008)

stunzeed said:
			
		

> True air cooling helps when the air you are pulling in is semi cool. When outside temps rise to 90-100 you are gonna have issues again. Especially if it is a totally sealed grow area. Air conditiong is the best solution. Try a small portable unit. They are pretty cheap online.
> 
> Good luck,
> 
> Stunzeed..



BUT with a portable AC unit, you MUST vent the exhaust outside the grow box so it is not recylced into the grow room. The AC exhaust vent hose releases hot air as well, so you'd be struggling to cool the heated air in the room also. I've been down this road, and ultimately, the only option I had, after spending 100's of $$ on ventilation, was simply reducing my power and wattage usage to reduce temps.


----------

