First Freezer Grow

I am setting up a stand up freezer grow.
Here's what I have in mind so far.

• 4 square feet of usable grow space. 22" x 24" x 48" (am planning for 4 plants)
• 8 - 45 watt (2- 2700k and 6 - 6500k) cfls sideways mounted on 20 x 20 hood. This gives me about 6000 lumens per sq ft. (Not bad at 360 watts.)
• Orca film throughout the cabinet and hood.
• using soil with perlite for this one.
• small pvc (2 inch id.) exhaust at top back of cab to a diy carbon scrubber
• 2 inch intake bottom center with intake filter.
• using this strain: http://www.cannabis-seeds-bank.co.u...h-ryder-autoflowering-feminized/prod_495.html
• natural co2 supplement (yeast, water, and sugar) NOTE: Does anyone know how long this lasts in the cabinet???

Here's what I haven't figured out yet.

• humidity source and control
• exhaust cfm

Any advise will be greatly appreciated.

I will post some pics this week of the design progress on the cabinet.