This is my 1830 half Cape. Mini-split is to the left and over the dining room window. One split cooled the kitchen, hallway, front den (not in photo) and the adjoining iiving room.

If you decide that someday you would stay into the fall, do both heating and cooling.

We had another installed for upstairs.

Mini-split heat pumps are a great way to add air conditioning to an older home. Installing mini-splits is less intrusive and less expensive than installing ductwork from a central system. Sizing mini-split heat pumps can be a challenge in older homes which have little or no insulation and higher air infiltration rates than more modern homes. Make sure your HVAC contractor knows their stuff.

We love our mini-splits in our 1932 house.

If you drive around the residential neighborhoods of New York city you will see many old houses with plaster walls with mini split condensers attached to their sides. All these house were built with no central AC systems.

On the other hand you can buy many window units for what it will cost to install two mini splits.

Minisplits are the most common source of air conditioning in the rest of the world. Not so in the US! They are still relatively uncommon here. The result is that many installers are unfamiliar with them and do poor installations at a premium price. Make sure to grill the installers on their experience and check references.

On a different note, minisplits serve a single space only. If you have an open plan home, that's great. If its an older home with multiple smaller rooms, not so great. Also, be aware that the interior cassettes can be mounted high on a wall or (less intrusively) in the ceiling.

A number of manufacturers offer mini-split heat pumps with multiple heads which allows for multiple zones of control. In addition to wall-mounted, and ceiling-mounted heads, some are available with floor-mounted heads.

Yes, I have a minisplit in my 200 yr old house, I think nowadays they all pretty much have both heating and cooling. Sales and installation is a total HVAC racket if you haven't already found that out yet.

We have mini splits on all three floors of our 1930 Dutch Colonial home: two are installed into plaster and the third into drywall. Love them and had no issues with installing into the plaster.
Highly recommend: we use them year-round. Obviously AC in summer but we also run them in winter so we don’t have to run our natural gas boiler so much in cold Connecticut. Have had them for 6 years and really worth every penny!

I don’t agree with the reasons for minisplits subsidies, but have some in my old house and it works good. It works really good for AC, much better than window shakers, but heat not so much.

Still worth doing though

Our AC wnt out at work over the weekend and the company i work for is having it upgraded to a mini split today.

I live in Maine so AC is not required, but nice.

The indoor units of Mini Split AC systems are visible within the living space, which may impact the aesthetic appeal of older houses with specific architectural styles or design preferences. However, manufacturers now offer a variety of sleek and stylish designs to suit different interior aesthetics.

If your home does not have a 200 amp service, it may need to be upgraded.

Not a big deal just an extra cost

To respond to two ’cons’ above, the mini split can be seen - so can a window air conditioner. And, old houses have poor insulation. - that is valid, but can easily be fixed with blow in insulation. or better insulation since you are opening the wall to install the mini split.

we installed three in our 1890 house. Huge improvement. I HATE window air conditioners!