A DIY garage mini split can warm your shop, but fit, leaks, and power count....
https://research-wiki.win/index.php/Should_I_Extend_Central_Ductwork_Into_My_Garage_or_Install_a_Mini_Split%3F
A DIY garage mini split can warm your shop, but fit, leaks, and power count. Learn to size it, check a 15A breaker, seal gaps, and price the job