Hi I am upgrading my 400 watt hps system to have two 1000 watt air cooled hps lights. I want to mount these lights to a 6 foot light track. SO I will have to use 6" dryer vent hose to vent it hence the light moving. What size CFM fan should I use for each light. Yeah each light will have its own fan.
Depends on your ambient room temps i guess.. If your room is in the low to mid 70's year round ide go with a 6 inch for each. If your room tends to be a little higher than that go with the 8inch just to be safe
Yeah I am going to go with a 6 in, but what CFM, do I have to get a big inline fan, or can i buy a 6 in inline fan from home depot that has a CFM of 160????? ANyone????
This is how you can calculate how strong your fan should be. Length X width X high=CF (cubic feet) (((((M) -minute FOR CFM)))) So lets say that your room is 8Lx5Wx8H =320 CF (cubic feet) . So to totally change air in your room with in 1 min you need 320 CubicFeetMperminute Fan. If you would like to exchange the air in your room with in 5 min then you take 320(CFM):5(MIN)=64 CFM. So to change the air in your grow area with in 5 min you need not less than 64CFM fan. Now, in your situation you can probably do this. Count each reflector as 3CF(cubic feet) and each foot of ducting as 1CF and each turn as 1CF. So lets say you have 4 reflectors with 12 ft of ducting and 2 turns. 4x3+12+2= so you got approximately 26 cubic feet of air(probably 20 or so) in your hood/hood cooling system. So to exchange the air in your reflectors and ducts in 1 min you need less than 30CFM. M- is the key word MINUTE.... We can not afford such a slow speed(do not forget about HOT BULBS). So to exchange the air in that system with in 10 sec you need to: 26x6=156CFM fan... to exchange the air with in 1 sec 26X60=1.560 CFM fan.. But this is overkill... .So for one reflector and 6 ft of ducting with 2 turns we can use 3+6+2=11CF, so 150CFM fan will push 2.5CF of air per second ,11:2.5=4.4 seconds this is how much time 150CFM fan would need to totally exchange the air in that small (1 reflector )system.....Again, this is just my guess... P.S> Please feel free to correct me if I am wrong. P.P.S. Slightly higher calculations for the reflectors and ducting were taking to compensate the air pressure in the system and for force that inline fan need to push the air trough..
Don't cheap out on ventilation. Get the best fan you can, if you have to buy a used one off of Kijiji or Craigslist so be it. You can always buy a new one later on if you wanted. You can save yourself a ton of money buying used gear if you know where to look.
Everyone misunderstood. I have proper ventilation for the room. What I am asking is what size CFM fan do I need to pull the heat off of each 1000 watt HPS light, So dont worry about room size and that I have that covered. All I am concerned about is what size fan CFM should I use to vent each 1000 watt light. I plan on hooking up a fan for each light. ANYONE?????
use one 8 inch fan.. and do not use grow space air... use another six inch fan just for exhausting grow space... get two fan speed controllers do not worry about CFM ratings... just get a six and eight inch inline fan... the cfm rating on any inline fan you get will do the job
I think you did not finished reading my reply to your post... I did covered fan size for one(each) reflector.....Basically you need less than 150CFM fan per reflector... But I would go with 2 fans max(higher than 150CFMs), one as an intake (to suck the air in to the system from the outside) 2nd one as exhaust (to suck the air out of the system)