[beenthere]

Do your tenats also complain that a room or 2 doesn't get as cool as the other rooms.
If so, you have some air flow problems also. So putting a 2 ton unit in on a 1.5 ton duct system will be nothing but headaches.

Your between a rock and a hard place.

A new chiller.
Or.
Or pay for line sets, electrical, 16 new OD units, drywall refinnishing, etc.
This is not a side job project.

 

[beenthere]

Get 2 or 3 contractors to come out and give proposals. And then come back here to ask questions.

Its going to cost about the same to replace your current chiler, as to do 16 individual units.

The difference is, that with individual units, they can pay for their own cooling, and heating.

 

[beenthere]

Yea. Your not going to get high SEER from them.
Probably better efficiency then your old chiller, but may not be a whole lot.