Ahh yes,
Now the pennie's dropped!.
I thought I'd seen them units used indoors.
Now- if you really want something else to smile about.....that dark yellow smear on the wall, under the disconnect, is the result of the nozzle breaking off a can of spray foam, as I was filling a hole in the wall!
I wondered what that mark was when I first saw these pics.
Them cans of foam can be nasty little buggers if they get out of control.
I try and avoid them and anyone using them at all costs.