Robert and Eric, I'm not sure where you would do a removable installation of a window unit on an Eco
. Like Bolers and vintage Scamps, it has jalousies on the side windows
and fixed plexiglass front and rear.
To me the options are a portable unit (still have to figure out how to rout the hoses), a permanent closet installation of a window unit (have to cut vent holes in the shell; tricky to get air circulation and drainage right), or one of the mini-split units
(which I know nothing about, but I've seen where others have used them).
I like the idea of a powered roof vent. It does better than a window or table fan, but it may or may not be enough.