They are made from 8 ft to 24 ft diameter. We have several at work in the parts/stores area. They actually had one running the other day when I was back there picking up a part. The Habitat for Humanity ReStore has one, apparently the HfH big boss saw them and decided that every store with a high enough ceiling was getting one. I was in there the other day, it was running full blast. Rather annoying, and quite surprisingly loud. Lots of gear/transmission noise. One of the volunteers saw me videoing it, asked why, I told him I wanted to record the noise. He said they ran it full blast because the people in charge think thats the thing to do. He said he told them they needed to turn it down so it would not bother people, but they don't listen.
.....on my soapbox now........I know he is telling the truth. The boss lady thinks she knows it all. Prices stuff at half of the HIGHEST retail price she can come up with, and claims it is worth it. They had real fancy spray cans of paint, were $8 to $10 in Home Depot, so she puts them up for $5. I tried to explain to her that they were OLD, out of date, possibly won't work, I was taking my chances, she insisted they were worth it. other HfH store sells any spray paint it gets for $2 max, no matter how good. They know the real world............. off my soapbox...........
Charles