If you’re thinking about a mini split heat pump for a smaller space, 110V/115V...

https://beaussmartwords.rivetgarden.com/posts/is-9-000-btu-enough-for-a-home-office-around-300-sq-ft

If you’re thinking about a mini split heat pump for a smaller space, 110V/115V models with 9k-12k BTU are a solid fit. They run off a standard 15A dedicated circuit and often deliver efficient heating down to -13°F