I don't think that I mentioned that I do still have one lower paying W-2 job, and rental income from my 1st property (short term rental income thru Air BnB) that brings in on average $1300 per month.

Looking back, may have just kept the wall units but central air seems to be a big draw for the renters.Future: Am looking into getting a HELOC/HEL on property to fund the next multifamily investment.

One trick I found is that old rubber air hoses make for good tie down straps and that romex or extension cords can work well too in a pinch.Another is that getting into a house without a key is usually not that hard so I don't worry about keeping track of keys of properties I am not currently working on.

And central air has different considerations than window units with central air being more desirable as long as it is paid for by the tenants.  

50 percent of being a successful landlord is having an air tight lease.

@Todd PowellI might be able to air b n b one unit.

 - One interior unit will be 12,000 BTU for a large living room/kitchen space, and a smaller 9,000 BTU for the bedroom.the total system capacity has to be able to cool both inside units at the same time so 21,000 BTU or larger for the outside unit.The beauty of these is that they can be installed DIY (provided you get your 608 certification card), as long as the line sets don't need to be shortened or lengthened, as there is no brazing/welding involved, just connect the lines and purge air, etc.my dual zone costs comes in at around 2.6k to 2.8k for my 800sqft structure.

In July I completed a lot of updates to the house (new well, new 200 amp electrical service and panel, new windows, replaced forced air ductwork, added a bathroom. 

We have a small air force training base named Laughlein.

I would like to learn more but when I look up articles it mainly comparision of standard rentals vs air bnb.