I believe you are describing something like this: https://mrcool.com/u-shaped-window-a-c/ https://mrcool.com/u-shaped-window-a-c/ Never used one myself but they

I believe you are describing something like this: https://mrcool.com/u-shaped-window-a-c/ https://mrcool.com/u-shaped-window-a-c/ Never used one myself but they are meant to be much better than the ones with ducts - you don't lose so much efficiency from the ducts or from badly patched up window openings.