Convection cooled closed av tower

[dano]

Hi all. I'm building a closed "reduced dust" tower for my av equipment and I'd like to know up front if my design will allow the heat generated by my components to be sufficiently dissipated using passive convection.

Basic design:
- tower dimensions are 66" h x 25" w x 25" d
- has legs that are 6" h
- inner cabinet dimensions are 59" h 24" w x 24" d
- shelves are 22" w x 22" d; they are "suspended" in the 24" w x 24" d space; they slide into corner columns that run the height of the unit, leaving 2" x 18" gaps on all sides of each shelf for air flow
- on the top and bottom of the unit, along the front, sides, and back, there are four 2" x 18" strips that are cut out of the wood and covered in screen
- will house a receiver, PS3, cable modem, wireless router, and phone charger (no set top box)
- distant future *may* hold a dvd jukebox, harmony charger, and / or PVR

I've tried researching the science of convection, but I'm not finding any simple formula that I can apply to my design... any advice or info would be appreciated.

PS: If at all possible, I would prefer not to use fans, as is discussed in this thread:
http://www.digitalhome.ca/forum/show...ght=convection