I actually have a window unit sitting on my fireplace right now.
I have a window unit that I use for power outages, we used it for several days during an outage in June. The fireplace was an out of the way place to keep it in the house, in case we had more storms.
It probably won’t rain again until October, so it’s probably safe to go store it back in the shop.
I keep a 110 window unit in the barn in case the power goes off in the summer for an extended period of time.