Trying to design my closet (still) and I was trying to figure out which would work best as far as stealth goes. For me, if I could have the filter be outside of the closet then that would allow me to maximize that space and keep the space as stealth as possible. I've read a LOT of posts arguing this little tidbit so I looked up my filter (Phat filter 12" x 6" ) to see if it had a preference. Nothing on the website where I bought it ( http://www.gianthydro.com/product_p/igspf126.htm ) but this statement: Given CFM rating is for scrubbing. Divide by 2 to get exhaust filter CFM I admittedly didn't understand the difference between scrubbing and exhausting so I sent an email to Phatfilter to ask. Just wanted to share their response in case it helps anyone. According to them, it doesn't matter. This was their response: "As with CAN filter, we decided to give minimum and maximum flow recommendations for clients because so many people were asking how slow and how fast their fan should be for a given filter. Generally, we scrubbing, meaning moving air in a circular pattern from a room through a filter and back into the room, the fan can be much faster because the air passes through the filter many times. When filtering, moving the air through a filter one time, the air should be a little slower to allow a longer overall contact time for the air with the charcoal. These are simply recommended flow rates. These recommendations have nothing to do with pushing or pulling through a filter, either is ok." So, according to their explanantion I can only run my fan at a max of 150cfm an hour (I think, lol). Closet will be 3'x4'x6' so that would be 72 cubic feet. Is 150 cfm going to give me enough air exchanges for a 400w HID? Neck/Tall Maximum Scrubbing CFM Maximum Scrubbing m3/hr Recommended Single Pass Filtering CFM Recommended Single Pass Filtering M3/hr 6x12 275cfm 470m3/hr 150cfm 235m3/hr
oops, I see the table didn't come out too well. Sorry about that. Neck/Tall \t\t\t 6x12 Max Scrubbing CFM\t\t275cfm Max Scrubbing m3/hr\t\t470m3/hr Rec. Single Pass Filtering CFM\t150cfm Rec. Single Pass Filtering M3/hr\t235m3/hr
Better to suck (pull air) so it pulls through any cracks, if you push, you push some of the air you are trying to exhaust out through any air leaks. I find pulling to be more efficient and easier also.
Thanks Bohbo! That would be my first choice if possible... Do you think 150cfm exhaust will be enough for a 3x4x6 closet?
If odor is a concern its better to push. That way your carbon filter filters all air in the tent and none escapes into the hood bypassing the filter.