I've always installed them with wall mount brackets. The room I'm in has no wall space and just enough room to put up a small shelf and stack all 3 units. I know it says you can do it. But has anyone done this? Results? I know there is side air intake and they are slightly separated. I just don't want to cause issues for the system in a few years. Thanks

Two girls later and I'm back.....lol...been gone a while but see same faces still here. Lol