I Started Growing with a 300w Micro-Grow Box 15 Years Ago

and I tell you what, Micro-Growing has come a looong way. :) The area where the most significant advancements have been made are in the lighting. I used twin 150w HPS lamps, scavenged from cooper security lights and I'll bet my box was drawing close to 400w through inefficient ballasts and lamps.

CFL and LED are Sooo Much Easier to Cool and Grow Great Cannabis

They require less ventilation, build up less heat and use less electricity. CFLs and white LED replacement lamps grow very potent cannabis. The only downside is a lower penetration, it's best to keep the budsites lower in the canopy clipped off, keeping all production in the upper reaches, near the best quality light.

LED Replacement Lamps (Image Source Shutterstock.com)

blynx Has Documented a Large Number of New Lights

All the data are on standard screw in replacement lamps, both CFLs and LEDs. I plan on building a few micro-boxes on the side here and went looking for good info on lights. This is definitely the thread with the skinny

PC Cases, Small Cabinets, Home-made Boxes

These lamps fit in an amazing number of small spaces. With the right ventilation and other conditions, you can grow cannabis in a variety of very unlikely places. :)

Light Coverage Estimates

I'm personally leaning toward the new led replacement lamps, they all provide enough light at 6-12" to grow decent cannabis in a 12" circle. A typical Mid-Tower, PC case works better with CFLs due to height restrictions. The new 14-17w LED replacement lamps have to be pointed, and are better suited for full-tower cases. The micro-grow section of the forum has a very, very large number of examples, dating back several years.

There are temperature and humidity requirements, air-exchange requirements, air-flow within the cabinet or box, odor control (if necessary) and more. I recommend reading as much as possible and then using a search engine to data mine the site for further information. Think site:icmag.com searchterms for best results.