As a Midwesterner, it is absolutely bonkers to me how common it appears to be for HVAC systems to get installed in attics.
Don't do that. Stop doing that! WTF?
That's bad enough, but then you go and run the ducts up there, too?
Y'all.
If you keep the system and the ducts within the space you're trying to heat and cool, you don't have to account for any losses, now, do ya?
Put the air handler in a utility closet. Run ducts /below/ the ceiling. Enclose with soffiting if you must.
The end.
@TechConnectify I know some condos in Texas have their HVAC unit mounted horizontally above the bathtub.
It was weird seeing that for the first time, considering I'm used to all HVAC units being upright/vertical.
@saiarcot895 ...above the bathtub? That's super weird.
Apartments/condos have always been more of a hodgepodge around here but if they've got central heating and cooling it's usually either a MagicPak (which is a packaged furnace/AC thing mounted to an exterior wall) or a conventional A/C and furnace. Same ductwork conventions apply, though MagicPaks are sometimes quasi-outdoors.
But, PTACs are common, too, and even some newer buildings have central heat via radiators but through-wall AC
@TechConnectify yeah, the condo I'm aware of that has this was built in the 80s, so I guess times (and ideas/planning) were different.