In that case I would purchase four window style air conditioner/heaters to mount into two of the windows per unit.That means each apartment will have two units they can control and this will be more than enough to heat and cool 1000 sf or less providing you purchase them to accomadate the correct square footage.The pros and cons of going this route:Pros:Cost.

@David Mount I don't have any experiences with turn key, but I do see the offerings.I've seen 1.5% but they are all in "c- or D areas.I have not seen any turn key properties in B areas, you can get 1.5% if you do the rehab yourself.I feel like those type of deals are kept in house.

Today there are many indoor units: wall-mounted, ceiling-mounted, floor-mounted, and built-in in the suspended ceiling - cassette and channel units.

Mount them higher in the wall out of reach from kids and thieves.

Mount Airy, East Falls, University City, Powelton Village, Fishtown.

My family and I do creative real estate investing in Skagit County, and really try to know the zoning of Anacortes and Mount Vernon, that has really helped us with our endeavors.

Believe me, the insurance company has no desire to pay out anything on your behalf, so if there's nothing there and it can't be settled for pennies they are going to mount a vigorous defense.

I mounted these, one for each county under consideration, in the "map room" of my primary home. 

I own multi-family in Stockton, CA (total of 36 units), condo in Oakland and two duplexes in North Carolina (Wake Forest and Rocky Mount).  

We would be looking near mount airy as well so even more of a single family home place from what I’ve seen.