Mini Split vs. Hot Water Baseboard

[Charles Stein]

Hi BP, 

I recently bought a duplex in Massachusetts which has hot water baseboard already installed in the first floor's rental. We will be installing mini-splits for heat and AC in the second unit. 

We are wondering if we should keep the hot water baseboards and purchase window AC units for the first unit or replace them with mini splits. 

Thank you!

[Jill F.]

Do mini-splits have heat pump heaters? Will that work when it's really cold in MA? Do they also have back up electric heat?