They are gas. Both are far away from the shop area, not even in the same room and are at least 12 inches higher than the shop floor area.
We got the house and I have started working on the back area that is already 7 feet tall. Turns out there was a slab under the carpet that has a few holes in it. I filled those and scrapped off all the old tiles.
Before I bought the house.
After I bought the house
Ramps down to the lower floor