6' or 8' hood for two 1k lights and why?
- Thread starter BluJayz
- Start date
lowrider2000
Well-Known Member
a 6' hood will give you a more focused light for a smaller aria dipends on the number of plants and sq fottage you have to grow
lowrider2000
Well-Known Member
it depends on your temps and how much air you need to move how big is your room what are the temps?
BuzzD2Kill
Well-Known Member
With only two lights id go with 6", cheaper, and the airflow doesn't need to be that great. If you pull through 4 or more id step up to 8". Remember to pull air don't push it. GL
BluJayz
Well-Known Member
I'm not getting my question across correctly.
You cannot "cool" a room by evacuating it. If you introduce air at 79 degrees and evacuate it; the room will never go cooler then the introduced air. (probably higher due to the ambient heat)
The evacuating i'm referring to would be strictly the heat put out by the bulbs.
I am used to seeing 6' for up to two 1kw hoods and 8' for 3 or more 1kw hoods; I am curious as to others.
Ah thanks for that! Wouldn't you push it to prevent the ducts from crimping up? Usually you're pushing especially when using a filter.
hunter21312
Well-Known Member
I have a 4x8 tent with 2k lights with 6in hoods my temps are always 75-80 and that's with the a/c unit off but because of the winter..I also have my carbon filter/6inch in the left back corner and it ducts right up to the lights so it has very little ducting from fan to lights..less ducting=more air flow...it such a perfect little setup..im gathering 30-40 clones to put in their soon and hoping for mhmmmm 2-3 lbs 
lowrider2000
Well-Known Member
the bigger you make the exhaust the cooler your bulbs will be and the cooler your bulbs are the cooler your grow is. i know its just a exhaust and not an ac so it wont cool more than the temp of the air your intake is sucking in but keep in mind light makes heat just like when your driving your car and your left arm gets hott as fuck but your ac is blasting 70 degrees. bigger tubing will aslo give you a chance to upgrade or add another light with out changing everything
CouchlockOR
Active Member
This is incorrect. I have two hoods one 6 and one 8 and they are both the same size and foot print.
I would determine if 6 or 8 is needed by how much heat needs to be removed. I was using 4 sunlight supply XXXL 6" hoods but switched to XXXL 8" to control temps easier.
lowrider2000
Well-Known Member
i think i saw a hood vent exhaust calculator online someware at one point
BluJayz
Well-Known Member
That would be cool to know the CFM needed to transfer 98% of the heat from HPS out the roof.
makisupa
Active Member
too much is always better than not enough. they make fan controllers if you need to lower the fan speed to raise temps a little. you cant speed a fan up past its max though.
i run 8" through a single 1kw hood, why not? price difference was nominal. its on a speed controller but usually its on max speed and my temps are ideal so its clearly not overkill. and this is in a garage that sits around 50 or 60 degrees not in a temperature controlled environment like a house.
i run 8" through a single 1kw hood, why not? price difference was nominal. its on a speed controller but usually its on max speed and my temps are ideal so its clearly not overkill. and this is in a garage that sits around 50 or 60 degrees not in a temperature controlled environment like a house.
BluJayz
Well-Known Member
I called the Can-filter company and was told you need 175 CFM to cool each 1000w light. So a Can-Fan 6'' would do 420 CFM making it enough to cool it. (evacuating the heat)
Thinking about that for a while I can't agree with it. Maybe in cold Canada it is enough but in ambient 90+ degree weather. It surely isn't feasible.
A 8'' Does closer to 720 CFM Giving 360 cfm to each bulb.
Thinking about that for a while I can't agree with it. Maybe in cold Canada it is enough but in ambient 90+ degree weather. It surely isn't feasible.
A 8'' Does closer to 720 CFM Giving 360 cfm to each bulb.
TheyCallMe2K
Active Member
If you could post a link to that dude that would be cool. Id be interested to see that