through the wall AC

I replaced two old Freidrich A/C only units with new 10-13K BTU ones from PC Richard for $600-700 each. Picked them up and installed myself in around 20 minutes. The hardest part is getting the correct size for the sleeves. You need to slide the old ones out to see the model numbers and get the updated chassis to fit. If you have real PTAC units that heat and cool you may need to special order to get the right heat supply wattage .

What about installing where there were none before? Replacing window with through-the-wall?

Falco - does it have the terrace you have so long desired?

And you are sure the building allows this and you are not in a landmarked district?

falco:
For a good job it's probably ballpark $4,000-$5,000 per unit. That includes the unit itself, all the safety equipment, insurance, protecting the surrounding areas of apartment, installation, labor, and clean-up, etc. Cost may depend on what floor you're on and what type of building. Contractor can also A/C enclosures like cabinets, collars, ducts, for a bit more, if desired.

This would not include landmarks permits/approvals, architect fees, or anything of that sort.

Some could maybe do it for less. We used Stanley Ruth and have been happy.

http://www.stanleyruth.com/

If there's any possibility of going (multi-)split ductless instead of through-wall, do that instead. Better in every way.

I recently paid $2,000, plus and additional $900 or so for the AC unit itself and about $100 for the sleeve.

I agree with Avm. It is around 5k per unit and Stanley Ruth is very good

2000 is not even close, for a prewar building in the city. I paid that 30 years ago, and I dont give money away easily. 5000 sounds more in line.

and alan is right re what he says. (here)

Alan - what is approx cost of the split ductless, and is this typically permitted in buildings that allow through the wall? Turns out effective AC may be driving factor in any purchase we might make.

Interesting you ask about split ductless. I found that it was a bit of a learning curve for my building at first simply because they were not familiar with them. After a bunch of wrangling about, they finally let me install one.

I think that the total cost for a single Daikin unit all in with wired thermostat, channeling, indoor and outdoor unit, etc. was like 9,000. bucks.

Alan,
(multi-)split ductless system is more cost effective but you end up with those semi unattractive units near the ceiling in every room. Astatically it's a loser compared to through the wall unless there is a way you can hide them.

They do make them with concealed units that usually are installed in closets as well

If you have drywall ceilings with some space above, or don't mind a little dropped ceiling in a corner, I believe they have ceiling cassettes or something like that. You can also build something clever at the useless top area of a closet to hide the ugly part. And ugly it is.

Also ugly is the exterior unit, placed indiscriminately, as is the case all over Asia. But the non-facade side of a prewar building ... perfect. I'm sororities cooperatives don't encourage that, to keep the facades unmarred.