need help with venting...

Hello there and thank you for reading. I have a Perfection Schwank 1988 model radiant space heater. 70k btu, model number WVRC270CTN-0. I obtained the unit for free, and was told that it works. The unit had a 6'' 90 coming off the back, appears to be galvanized. My question is this: what kind of chimney should this unit vent with, and is it worth hooking up? I'm wanting to put it in my unfinished basement/garage. I've had no luck fishing around on the internet for any information as to how this unit is supposed to be vented, and have never seen anything vented in single wall. Just trying to get heat down here as cheaply as possible lol :) Any advice is appreciated!