Several years ago at factory service in Forest City I noticed a Vectra with three rooftop airs
, I thought this was a prototype or something like that. When I asked the owner, he simply replied that he "likes it cold." Okay then.
One rooftop air will not provide enough BTUs for cooling, two might, three for sure but that's a lot of weight up there if you have other stuff installed on the roof. Also, the roof airs would need to be heat pumps or have heat strips (not very efficient.)
For the DIY guy, I would
much prefer to pull a basement air unit than horse a rooftop air off and on the roof.