A question?

How important is a intake fan. I just installed an exhaust fan. how important is an intake fan? I have three small plants in a cabinet running four 26w cfl 6500k 1600 lumen. (Im going to upgrade to 42w when i get the whole thing situated). I really only plan to keep two out of the three plants as long as they are good girls. this is all new to me so any advice or tips would be greatly appreciated!!

Intake is un-needed as long as your exhaust is strong enough to create its own natural sucking(intake) My grow tent has top 6" duct.. I have a 400 CFM inline fan sucking air out into my attic. My grow tent has 3 rectangle intake holes at the bottom which have cool fresh air contantly getting pulled in. Just think, if you have air blowing out, you will have air being sucked in, this intake air you want at the bottom for many reasons like plant needing fresh air below.

yeah i never thought of just putting holes in. thanks!