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

https://annamaid.com/how-do-i-pick-between-9k-and-12k-btu-for-a-500-sq-ft-garage/

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