Window replacement / AC

How big is your co-op? Is a big job to start putting holes on the walls for ACs and can cause lots of dust which can be a big problem for people with allergies.

It woudl make sense but before exploring your options, I would advise you first consult with your managing agent. Coop boards have rules and regulations concerning AC units.

If the coop has money to spend on this, worthwhile approaching the board. Typically, there is an assessment to cover such expenses. What you are proposing may easily double or triple the expenses. And through the wall units are more expensive than the window units.

We have 1,000 units so this would be a pretty big job.

It also depends on whether the building is landmarked or not.

Would you be doing the mini-split at your own expense? If so, you should go for it if you can. I'm at the moment submitting for plans to do that in my reno. For a 4 zone I was quote roughly 26,000. So I imagine if you were putting in one it'd be a 1/4th of that? The thing is, where would you put your compressor? Mine is going out on my terrace.