My building is 30' X 60' with a 16' ceiling. It also has a 13' deep 60' long second floor over the one bay. It's really more like a mezzanine. I was using a Craftsman shop vac to pick up saw dust, dirt, leaves etc. It got
real old real fast dragging that thing around behind me, not to mention the cord wanting to get caught on stuff. That's when I decided I needed a central vac unit in my building. I did a lot of looking around on the Internet and ended up buying 2 units from Central Vacuum Stores out of Florida. Here's the link (hope it works),
https://www.centralvacuumstores.com/
I sent them an email on a Saturday morning about "closeouts" they mention on their website, describing the size of the building and what I would be picking up with it, then went on about my business around the house never expecting a call until the following week. Within an hour they called me back and left a message on my cell phone. When I returned the call they said they had some units that would work great for what I was after. The units were taken out of new homes that never sold and still had the manufacturer's warranty. They recommended the garage kit for attachments and 50' of hose to make it to each end of the building and upstairs. I ordered 2 of them, each with the 50' of hose and attachments, the other one went into my wife's shop. Each unit was $175 shipped to my door. I don't have the invoice in front of me for a price on the hose and attachments. My vac unit is mounted in the bathroom that's about in the middle of a wall. I mounted it and hung the hose and attachments inside the bathroom and plugged it in. I did not vent it outside or put a muffler on it. I did add a muffler on my wife's and it is just fine (not vented). It has been one of the best things I have spent money on for either one of our buildings. The noise for me isn't really an issue in my building. It's not any louder than my shop vac. If it gets to be annoying then I will get a $13 muffler from them like I did for my wife.
I personally don't think there is any comparison using a shop vac after going with a central vac unit. I pull the hose off the hook and go to town. It doesn't get much easier than that. I don't see any "dirt or dust" in the bathroom because of not venting to the outside. They said this unit does not need to be vented. My Vacuflo in the house has to be vented outside.
YMMV
Steve