[Prekursor]

There is a buzzing noise when I turn the unit on and that sound can be heard in the adjacent room. The noise comes from the side of the AC condenser.
I recorded a video and attached it here: IMG_1630.MOV
Thanks for helping me identify the issue. Brand is Carrier and it was noisy from the beginning I just not realized how noisy it was until I replaced my other unit with American Standard unit

 

[channellxbob]

That buzzing in a scroll compressor and although it's a normal sound, it's annoying for sure. You would have to get a technician out to look at the side panels and top of the unit to stop some of the metal rattling, but that compressor, assuming all else is well, is just going to make that sound. Isolation is the key, set the unit on pads, make sure the panels are tight and not part of the problem.
We see this quite a bit and sometimes, the answer is hard to nail down, but it's definitely vibrations.

 

[channellxbob]

Definitely the scroll sound. It might help to put your hands on the unit at different places and put some pressure against the unit to see if it quiet the sound. I hate to say it but some units are noisy and some are whisper quiet. we install a lot of Coleman / evcon units and they have always amazed me how quiet they are, so much so you'd swear the compressor wasn't running. I feel for you and if I had installed that unit, I'd be looking for the vibration and talking to Carrier support for help.