Is A/C a reasonable investment?

[Corey Mohar]

TL;DR - is a/c alternatives to window units a strong selling point to potential tenants?

So in March I purchased my first property. I have a lot of student loans so I decided to house hack in a single family home in an area that allows you to rent out rooms to non-related persons. Currently I have one tenant (a friend I went to school with) and that covers about 2/3 of my expenses. I'd like to rent out another room, but one of the rooms in my house is a finished attic that will need a mini-split to handle the heat load. I've tried a portable unit but it can't keep up on hotter days and has to run 24/7 and is overall inefficient. I've gotten quotes for just that room, but I'm looking at getting the rest of the bedrooms done as well and it's really not that much more expensive. The house is semi-detached and duct work isn't an option for the upper floors. I've been running the numbers over and over again. If I were to get all of the rooms done, my expenses only really go up by 100 dollars a month, and I would be saving on electricity (due to Covid, many contractors are offering 0% financing so it's definitely a convenient time). The return from getting a new tenant would completely offset the cost, and even bring in profit. But in the long run, is this something that would typically improve interest in my home as a rental property? Very few houses in the are offer a form of air con that isn't "provide your own window units." I will definitely be getting the one room done, I'm just curious if investing in the rest of the house is worth it! I'll be living here for at least two years, and definitely wouldn't mind having it myself.