Using one as a fermentation chamber right now.
Inside 23" wide, 15 1/4" front to back.
Non-humped floor 15 3/8" wide, 27 1/2" tall.
Humped floor 18" tall.
In my drawing program, looks like 3-9" diameter kegs and a 6" diameter tank fit, but not sure about regulators, hoses, etc.