Wow that funny !

Can a domestic rooftop ac be mounted vertically

Kyle, you’re my new favorite person.

So Kyle, we really don't know what would happen because no one has tried it....even in LAB configuration. I think it could be possible and would like your team to try it.

When replacing r22 ac and gas furnace install. To a modern freon ac condenser and coil do you need to change line set ?

We need to replace a very old Carrier Quietline Unit that is, by desigh, mounted vertically through the wall (15.5 inches wide, more than twice that height). Can we use a split system, mounted outside, and with the cool (or possibly also heated) air then vented through the vertical opening in the wall? Is there any way to do that?

That is why we ask questions, was thinking about a mini- split mounted vertically did not even think about the condensation factor. Thanks for the answer about where the condensation would go ?

Concerning the question "Can I Install a Ceiling Air Handler Vertically?", the answer is yes, and condensate will not run all over your walls and cause problems. Air handling units can be installed in the following configurations (1) up flow (2) down flow (3) horizontal left discharge, and (4) horizontal right discharge. As an example Rheem AHU's come as "Vertical Upflow & Horizontal Left Discharge is the factory configuration". For Rheem AHU's "The unit as shipped from the factory is not configured for vertical down or horizontal right discharge applications and must be converted in the field to work in those applications." This common language for all of the manufacturer AHU's that I have installed.

So.... if one were to install a drip pan and drain under the unit, installed vertically, that might resolve the water intrusion issue -- however -- what other issues might come up? Might the coil condensaion drip into the electronic parts of the unit? Can the unit be positioned in such a way that it could be used with a drip-pan at all? The obvious answer is that it's a ceiling unit and was designed with gravity in mind. The question probably needs to be asked of the individual manufacturer, but the most likely answer will be ceiling units go in celilings. That said -- can't hurt to ask. And ask that the manufacturers look into alternate configurations, like in-wall units. In two of my houses -- I could easily have a flush mount in a bedroom wall, and the guts of the unit on the other side in a closet. BTW: mounting these things other than how the manufacturer states will kill the warranty. Ungood...