Personally, I've seen cash flow yields ranging from 10-18%, with plenty of potential for even more.

4) LTR projections range from $1600, which is from bigger pockets rent estimator to about $2500 from looking at comps in the area.  5) Top properties do about 10 to 15 grand more potentially, in 50k+ range which we would be happy with.

I am covering utilities for the 1st floor and garden unit (for a 3-unit MFH rental)Any recommendations for a programmable thermostat where I can lock appropriate temperature ranges?

With a rate for a first mortgage today in the 6-7% range something like this probably is going to be close to or in the double digits. 

Quote from @Min Zhang: Hey Alan, I have seen areas like Cleveland and Dayton with COC ranging from 10-18% and Columbus is around 8-12% with strong growth. 

I've had success with 2 short-term rentals, and wanted one more in relative close range to work and life.

Google search gives me these super wide ranges and mostly talking about adding a bedroom in a SFH, which I'm not sure if applicable to this situation of "moving/subtracting a bedroom from one unit and add it to another unit in a duplex". 

As mentioned above your new rate should actually be 6-7 range not 8s so shop around.

Investing in multifamily properties in Philadelphia is popular due to the city's steady population growth, job opportunities, relatively affordable property values, and solid rental demandPhiladelphia’s multifamily market offers a range of opportunities, from high-end neighborhoods to up-and-coming areas with great cash flow potential.

The bigger the property, the different the agent on the commercial side.Multifamily in the 10-30 door range