quick airflow question

i cant remember the rule of thumb for airflow, was it romve all air in room 2 times per minut?

so for a 100CF area u would need a 200CFM fan

or was it 2 times per hour?

lol i never remembered cuz i always use to use an AC unit in a close room setup, i am now gana attempt my 1st grow in a vented room with a carbon filter

any tips or heads up would be kewl, like i said i always used A/C and dehumd with no exhaust. im looking at doing a small room bout 10x10x10 maby a lil biger just a quess. i am going to build a filter box using carbon and furnace fiilters and plywood, then put it inside the room onn the ceiling in the corner. then outside the room (inside wall of house) put a vent in to let the scrubbed air out. what kinda CFM and how much carbon am i lokken at needing

I would reccomend replacing the air 3 to 5 times per minute. a room that is at that size would need a big one or multiple. 1000cfm minimum and multiply that by the air per min that you want to replace. That's my 2 cents.

i vent my 70 cubic fooot room with a 424 cfm fan which turns my room about 6 times a minute.
i think rule of thumb says 3 times a minute which you would be at 4X per min with a 424 cfm inline as shown here High Tech Garden Supply

you can probably find it cheaper elsewhere but i wanted you to have an idea of what i use

even though i only have 4x400w HPS
yea the room is 10x10x10 but im only growing in about 7x3x10

so should i wall off the area wit hthe plants or just vent 5x the space tha tthe plants and lightrs take up??

i dont see wy i would have to vent the entire 10x10x10 5 times a minut if the plants and lights only take up a small corner of the room??

so again should i wall off the section the plants are in and vent that, instead of the whole room???

putting up a wall might help by allowing you to put some mylar on it and reflect light to the plant.
otherwise there really isnt a reason to build a wall.
just keep a fan blowing in the room to circulate air and vent off as much as you can with what you have ... it will be fine since the whole room isnt full of plants eating up the CO2

im more concerned about heat than co2 , with 3x400w HPS and 1x 400w MH and the room door shut it could get toasty.

i just wana make shure it stays cool enough,and the air comen in will be between 65 and 85 depending on weather and season

those number were just estimates its more like :

room 12x12x8 and the 4 lights and plants will take up 5x5x7

i plant to cut a hole in the wall and put vent over it then use a fan from walmart, or home depot if i have to

realy i just wana get a good box fan like the kind u put in the window put a thin DIY carbon filter behind it and have it blow out the hole in the wall

i just droped 55 on seeds and 130 on nutes and medium, i kinda need to get sumthen cheap

i was thinke nmaby sumthe nliek this if a cheap 20$ box fan wont work

20" High Velocity Floor Fan

that 1 is only 52$ and i can easly add a filter behind it and put it up to the hole in thw wall and seal it in

4 x 400 hps could definatly get warm but you can combat that with cool tubes which i use and swear by
the lamp in a 400 hps is small enough you can make your own cool tubes with pyrex bake-a-round tubes which you can find on ebay for 5 bux each
the box fan will work if its sealed in to force air out thru a scrubber

i been looken all around i canr find the CFM ratings on cheap 20$ box fans

i would liek to just get mabay 2 box fans from walmart and use 1 to force air out (passive intake) and the other to blow air around the grow room

just wish i had an idea of how much air a cheap ass box fan moves

its gonna be over 250 cfm on high for sure