I went with a ductless mini split to heat & cool my shop space. I live in Wisconsin so I’ll see a wide range of weather!
Lots of HVAC guys didn’t recommend mini splits because their knowledge is about 20 years out of date. The ones who are familiar with modern mini splits all recommended two blower units to adequately cover my 900 square feet so that’s what I went with.
I got the 18k BTU Fujitsu Halcyon outdoor unit, model number AOU18RLXFZH plus two 9k BTU indoor units. The blowers are placed along the long wall (20×45 space) at about even thirds. This arrangement works pretty well as they are able to cover the majority of the room with full-speed air.
This is a two-zone system, meaning that each indoor unit is designed to be installed in a separate room. They work just fine alongside one another but it’s a bit dopey having to operate two remotes for one room. There’s no way to link them together.
Mini splits, even the super efficient ones, are not as cost-effective for heating as natural gas. Over the first winter with the system we had two quite cold months and I observed a roughly $100 increase on my utility bill for each month. Heating the space with natural gas would not have been free but I bet that the increased cost would have been less.