Ok when you say 4 square feet, are you talking about the volume of the box, or the square area of the floor.

Length X Width X Height will give you volume.

Another factor is the lighting, that is why CFM is important. Enough lights can oush your temps well above 90 degrees, which would not be good for the plants.

If you don't have a thermometer then get one, and the I would personally get a a Fan that moves a minimum of 85CFM. Tight now I use a 235 CFM, but have learned that those fans can be noisy, So I lowered my voltage to lower the speed and noise of the fan

Also tempature in your room is important, because you have to have cool air coming in to help keep the temps down and the plants need fresh air also.

I know it sounds like alot, but with a little trial and error you should be ok

K my bad I meant 4 cubic feet. And in there I have 8 26watt cfls and 2 13watt cfls. And I just got a thermometer/humidity meter(refer to pics) being my first grow it is coming together slowly. I think I killed my plants by adding a bottle for co2 and it screwed my water/nute uptake not sure if they'll survive. If not I can always try again. And should I add a fan control? Thanks alot man.

You definitely have very limited height in there. You will have to LST (Low stress training) to make up the difference for the height.

Watch your temps, if they start to climb above 85 the plants will suffer.

If you can try to get another box with more height (Thrift store. I got a portable closet for 15 bucks) Get higher CFM fans (Ebay)

Just my advice. Wouldn't want to see you start a grow then have to start over