burglar-proofing thru the wall unit?

How do you do that? I had older units i replaced in the past few years but someone made me realize that all you have to do is push them in and you are in.

My one i actually had to make the hole bigger by 2 inches and chipped out concrete block to do so but the other one i used my old AC sleeve and just slid this new one in. That sleeve was in there so tight i couldnt get it out if i wanted to so i figured hey it's in there why not let it be?

I'm assuming i should brace/bracket into the wall somehow but that seems really intrusive and ugly looking

 

What happens is they push the chassis in and crawl thru the hole in the sleeve. The unit where you had to enlargen the opening, that sleeve should be attached to the wall. New units usually come with a small bracket that attaches the chassis to the sleeve. Have you checked for that?

 

hmmm i dont remember if i did that with the new hole or not. Probably not. attaching a sleeve to a wall seems pretty ez relatively, even after the fact (heck i just bought concrete screws for another project). But i worry about how to attach an AC unit to the sleeve but until i pull it out i guess i cant tell how they intended it or where to do it

i could always dig out the instruction book now that i think about it

also the one i had to make a bigger hole, i had to do that in 101 degree heat, direct afternoon sun in july, so it was more like , make this hole bigger and get it working!!!! vs make this secure

 

Here they often have a security bar company make a cage to go around the outside.