I'm wondering how loud the actual (no amplifiers) sound of a semi-hollowing electric guitar is compared to an acoustic.
Not as loud as an acoustic.

Not as quiet as a solid body.

Kind of like ...

a semi-hollow guitar.
I see... so the primary purpose of buying such a guitar, really, would be to capture its warmth rather than have a versatile performer. Thanks guys.
A larger semi-hollow is quite a bit louder than many solidbodies, in my experience, but it's not much good without an amp. You probably won't be able to play with any other instrument and certainly not to a crowd.

There are acoustic archtops that were designed to be played without an amp. Doubt many, if any, are still made though.
This space foreclosed, due to the ailing economy.
If you want volume without the amp, get an acoustic, and get a pair of acoustic pickups.

This coming from a guy who knows nothing about acoustic guitars (other than that the strings are too high on my dad's guitar from College) or acoustic pickups.
"Dude, you gotta pull an "Axl Rose" on them.
Tell them it's your band, if they don't like it, they can get in line and kiss your ass." ~pablo_arg