How important is it for the fan to be on?...Is it just mostly for odor control?

Hey gang -

So I have my room set up and I have a computer fan/vent coming in from and several feet away another going back out to the crawl space. How important is it that these fans are consistently on? Are they mostly for temperature control (shouldn't be an issue...using CFLs) and odor control? With the vents, the room should naturally be getting some fresh air in there, but I'm not sure if I should turn the fans on and if so if they should always be on?...only on when the lights are too?...or only on when stuff starts to get smelly?

Side question...does it only really get smelly during flowering?...or does veg smell too?

Thanks!

as far as smell that depends on strain,the fans help grow stronger stems which means bigger buds usually

you want to bring fresh air in and suck heat out, however you do that is up to you. Oscilating fans on the plants build stronger stems (its like excersie for the plants) like dump said.

You have to have a fan...period!!!

u always want an exhaust and circulating fan on(intake is always nice too)....exhaust will do wonders for temps and circulating will both strengthen ur plants stalks and help prevent mold....

circulation in the room is the key ... if you run c02 you have no reason to run exust except for heat issues... if you dont the room can drop below 200ppm and the plants slow to a crawl...i ran out once and my room was sealed at a geat temp but 200 ppm~!!! YIKES JUST ME BREATHING it jumped 400ppm in five minutes... so sleep in your growroom with the lights on

shouldn't be an issue...using CFLs

Click to expand...

um ... enough CFLs ( having like enought to get a good yield ) will heat up your room lol . I have 6 CFLs in a 50cm X 60CM X 50 CM, that's 1.5 cubic metres for 150watts and it get to 38 celsius without fans. I reach 29 celsius with 2 pc fans

Its all about O2 and CO2 exchange. You need the fan so your plants can BREATH. Your plants don't have lungs so they rely on passive air exchange or wind. Another option is to pump the room full of CO2. The plants can handle higher levels of heat and they will grow huge.