I am currently growing in a space 24 inches high using CFL lighting and the SCROG technique.

I kept the light within 1 to 2 inches of the plant during veg cycle and this helped to hold down the vertical hieght of the plant. The screen helped to hold down the hieght during the flowering stage (I am on day 40 of what I expect to be about a 60 to 70 day period of 12/12).

It is possible to grow in such a tight space but next time I will be using a cabinet about 36 to 42 inches tall. Also I will use an HPS light for the flowering 12/12 cycle because the CFLs seem to take a very long time for flowering production.

SCROG or at least SOG is necessary for production in small places. Otherwise you will not get enough buds for the time and effort/expense involved. I currently have 16 bud sites above the screen and will get a decent yield but I expect very much better results in my next grow using the CFLs for veg and the HPS for flowering.

regards, hope this helps a little,
Max Blast