how many boxes into a L shaped room- please help!

The storage space measures 8.5ft x 4 ft. The storage room is 7ft high but half of the room the ceiling is only 3 ft in height.

Boxes are 24inch x 24 inch x 18.5 inch. how many boxes can fit into room

So i can picture the room draw it out, and then make all measurements in the same units. what should be next step. the awkward measurements mean there are different ways the boxes could be stacked?

What is the best method to solve this problem? http://www.mymathforum.com/images/smilies/icon_eek.gif

Thanks (Headbang)