speaking of warmth, gradient, heat, etc...

I just redid my garage, i.e., the back wall, both sides and the ceiling (I framed it, drywalled it and put insulation in the walls.

I also put in 3 vents along the bottom of the garage to control air flow, but the issue I am having is heating the garage to approx 80 degrees, which is what I want to achieve.

Does anyone else do the garage thing? Any pointers? I should also add the garage is detached and has a normal garage door, which further complicates issues.

Thanks,
Brandon