What about installation of the compressor unit? Isn’t that outside, and, if so, does it need a concrete pad?
—”What about installation of the compressor unit?”
Just like my old unit, precast concrete patio squares from the big box store.
Not required, but to keep it out of the snow I made a short stand from leftover strut and added a patio block under the unit to dampen vibration.
My brother mounted his directly to the outside wall of his house and said when starting under load he can hear something, sometimes.
Being hearing impaired since RVN, I placed my hand on the condenser and sometimes can feel a slight vibration on the unit but nothing under the inertia base/patio squares.
Because it uses a frequency drive to modulate the compressor and fans, guessing the vibration is transient/load dependent.