to insulate or enclose?

The people who tell you to enclose the door are correct. It will hold heat and cool better

>>1095040
that settles it

>>1095039
It's a small space. So just throw some blanket type insulation on it like in your pic and crank up the AC.

Proper insulation would vastly decrease the amount of time the AC has to run. For that you would have to build a proper insulating wall over the door, but also over all your other walls (which are almost certainly single walls with lousy insulation value).

>>1095039
What do you mean by enclose? Fill in the space with wall? It will definitely be better to turn it into wall.

If you aren't going to be opening it for a while, take some foil take and seal it all up. I have a garage I work in all of the time and I leave the door to my house opened and it has a cheap plastic and foam door that seals well so it stays very nice in the room. I think all you really need it to keep the room sealed up well.

Detached garages are poorly insulated. You would not achieve much by just insulating over the doors. You would need to retrofit the entire building from top to bottom which will be a very major job. It's not worth it. Just deal with the temperature with fans and cold water or layer up with hot coffee/tea.

>>1095187

Correct. But if the walls exposed 2x4 or 2x6, batt insulation on them will make huge difference. If the walls are drywalled, just drill small 4in holes in every stud bay then dense pack in cellulose, patching the holes is easy. Of course if the roof has no insulation and is a truss design, either batts or more blown in insulation.

Look at it this way, insulation is a one time purchase. R30 will stop 30x more thermal energy than R1 or R0. Energy bills are reoccurring, especially those used to heat/cool a poorly insulated R1 structure.

Insulate first or don't even try to heat/cool the space.