Carbon Filter / Fan Combo, how much cfm do you lose?

Hello riu, this is my first grow and i just want to make sure i get these small details down. i'm sure this question has been asked a bunch, but i can't seem to find an exact answer on any forums. So i have a 4x8" CF attached to the S&P TD100 fan right now. The set up is CF -> Fan -> Exhaust. I have a 150w HPS set up (no cool tube and built in ballast) with 120mm case fan with 40~cfm as intake. Box dimensions are 36Hx18.8Wx21D". I put 1/2" styrofoam along the walls as panels to keep down noise, and since i couldn't find any mylar where i live, i used reflectix to line the cab, but recently ordered b/w 6m poly to put along the doors and floor to keep it light tight and clean. I've only tested the box once so far and by the looks of it with lights on it runs 85F~ with 39%H. I know that ideal temp is mid 70's and RH 40-50?. I've also ordered a 5" O2 fan for some air circulation. So basically my question is, are my temps too high b/c of all the insulation, or is it b/c my fan isnt pulling enough air b/c of the filter or my case fan sucks o.o idk really lol. And would installing the O2 fan bring temps down at all? Any help would be great thanks!

oh and for any other details, just germinated one NL auto from nirvana using the shot glass method. within 12 hrs it sank to the bottom and i put it in a jiffy pellet, covered the dome and put it inside my empty grill outside for now. (too cold in the basement where i live, ironically my box hit 85F). Gonna be using FFOF in either one or two gallon soft fabric pots with 70/30 perlite in the mix. Nutes im guessing the FFtrio but i havent quite got down the feeding schedule for autos, especially using FFOF i feel like i wont need nutes for the first 2-3 weeks, but people say autos need some veg nutes? idk =(

EDIT: oh yeah sorry i have one more question, im holding the fan/ filter through flex duct with electrical tape. pretty solid, but still i see some carbon seeping out. is this normal/safe? any way to deal with it? tyvm

nothing?? no one? =(

http://urbangardenmagazine.com/2010/07/planning-your-grow


Check this link.


It explains all the math.

Including things like 15-20% loss for a carbon filter.
15% increase required to room CFM for 600-1000w non air cooled lights
5% increase required to room CFM for air cooled hoods.
Ballast placements res placements etc etc.




J

jondamon said:

http://urbangardenmagazine.com/2010/07/planning-your-grow


Check this link.


It explains all the math.

Including things like 15-20% loss for a carbon filter.
15% increase required to room CFM for 600-1000w non air cooled lights
5% increase required to room CFM for air cooled hoods.
Ballast placements res placements etc etc.




J

Click to expand...

i'll give that a read. thanks a bunch. but the only problem for me is my ballast is attached to the light so its prob putting out an extra 10 degrees or so? and i dont have very much space or tools or cash to work with =/. And might you have any info on the leaking carbon?

Depending upon brand of filter it could just be some that has fallen out.

I generally have to empty the inside of my filters when they're new because of debris carbon.

Are you using a pre-filter on yours?

Is your issue with carbon falling into your grow area/plants?


J

i used phresh 4x8 filter and i notice some carbon falls out over my grow light. my plant is still germing in the backyard grill for now. and yes im using a prefilter

I use CAN myself and have never seen that problem.

Especially with a prefilter.


J

=T woulda gone with the can, but i got my phresh for pretty cheap on amazon and its extra light weight o.o, anywho thanks