@Evan Polaski from my experience the "conversion rate" is depending on your target market and list.when i say conversion i don't mean closed deals, I mean a respond and ongoing conversation..with cold calling the key is to first get a Cellphone that is actually belonging to the owner, more often then not they are disconnected. when I started targeting my list I had about 12-15 respond rate, then it went down because we took people off the list and follow them up periodicity directly 

Disconnect everything.

Did anyone check the time delay fuses on the disconnect?

Appraisal costs generally run around $500 so I'm not sure where the disconnect is.

-One of the exhaust fans from one of the unit's bathrooms is disconnected in the attic, so the fan essentially blows air from the bathroom into the attic... 

The number is disconnected and the address provided is to the property I know is vacant (I see it every day out my window, trust me, it is vacant).

How do I locate a contact for this vacant property if the property owners appear as deceased, phone numbers are no good/disconnected, what's next on my research?

I agree central a/c is the way to go.But you will need the a/c condenser, a pad (or suspend it on brackets), evap coil, line set, electrical circuit & disconnect so you're probably looking at closer to $2500-$3000  using compatible Goodman parts & depending on what they charge to install it, (usually around $800-$1000).

I think there's a disconnect between some degrees and the real world.

Yes, you can disconnect.