A former neighbor of mine rented a blower that would blow in insulation through a hole in the drywall. You just cut a hole (about 2" or 3" as I recall), fill up the area behind the drywall, and re-plug. In a garage, you probably wouldn't even need too elegant a patch job.

It's possible there may be a 2x4 block between studs, which would mean 2 holes per spacing.

This was maybe 12 years ago. I think he rented the equipment from the same place where he got the insulation.

Thanks for the info.
I will look into that idea.
I just want to be able to put a freezer out in the garage and I don't think I could do that without insulating it.
Thanks again!

You're welcome, Pekoecat!

The 'blower' is kind of like a reverse vacuum cleaner with a huge hopper on top of it. I've used these a time or two myself (for adding to attic, not through holes in the walls). You (or, preferably a helper) add insulation from bags as you progress. It definitely helps to have a helper because the hopper's feeder can get clogged & need attention.

---> One thing to remember about blowing in insulation inside the walls!--DON'T DO TOO MUCH OR GO TOO FAST! It can shove the drywall right off the walls! This happened to my ex-neighbor in a couple places.

---> Oh, and: buy some dustmasks! Messy work!

Good luck,
-k2 in CO.

We have had a outside chest freezer outside for (the same one) at least 20 years now in a garage that is not insulated,and right now it is -27 below zero in Northern MN.
I guess if that is the only reason why you are insulating,I personaly wouldn't go thru all the BS and messy work of doing it.(just my opinion)