I have a small unit that will bring the garage from 22% to 55% in about 15min.
It's about 22 x22 and insoulated, Runs on elec which is cheap hear.
This is good only when working in the building, as it has no thermostat.
Brought my spare to paint shop, they matched the color in spray can and
a bottle. Did pinstriping with bottle and will use can to touch up wheels.
Not too expensive.