The air conditioner has not worked in about 3-4 days.

If you're gutting the entire place: then I would put in furnaces with air conditioner and dedicated ducts/systems for each unit.

A couple of weeks ago, I passed by the smaller unit and heard the air conditioner was running, so I asked another tenant about it.

They'll probably use a window air conditioner.

Repairs were estimated at $37K but we ended up with $50K due to unexpected air conditioner issues plus a few misc things. 

It is in a good location, close to shopping and an easy commute for multiple large businesses but located on a busier street.I did an extensive walk through today and the rehab includes the need for a new air conditioner, stove, siding, 5 windows and one sliding patio door along with replacing the majority of the flooring as the carpet is beyond it’s usable life.

You’ve got to turn the air conditioner on if you don’t want it to be hot! 

I had one contact me last summer about the air conditioner not working.

Property condition: if all 3 properties have original water heaters and air conditioners from 1980 there is a strong chance those are coming due shortlyI have seen many recommendations for $5-10k per property for a safety net and follow that guideline.  

The buyers contacted us directly and asked for the "date of the air conditioner".