Years ago I used the 3P index... pawn shops, porn stores, and payday loans. .. too many too close and it’s still too early.

The Freon system is made up of copper tubes that are soldered together into a sealed system when the A/C is installed - if the installer puts the right amount of Freon in at the beginning, it stays there for the life of the system. 

I am under contract on a fully occupied triplex in Independence, MO that the general inspector found some electrical issues with and some concerns regarding Knob and Tube wiring.   

Then they demanded a roof to cellar electric system, after the inspector noted porcelain knobs (knob and tube wiring from the 1800’s to ~1930 was dangerous) but there was NO wire.

Read read read and watch you tube on whatever niche you are interested in.

In fact, I knew that it should take less than 1 tube, but I just gave him a box with tubes.

If they see knob and tube, asbestos, water in basement, or mold they generally freak out.....even if it may be less than $2000 to fix. 

I found bigger pockets searching you tube for passive income. 

I thought that I would only be out of normalcy after 6 months but that has turned into 7 years and I still eat through a tube that should be replaced about every year and a half. 

(all new copper tubing)I suspect your carpet life might be a little long, I think you will replace it more often., IMO I would avoid carpet if at all possible.