Air Condition humming noise
A major part of the problem is the way the condenser is mounted. They are normally set on a concrete pad a few feet away from the house to facilitate air flow around the unit. Your condenser is mounted on steel brackets bolted into your foundation so the vibration, which every unit has, is transmitted right into your house. Check to see if there are any type of vibration mounts between the condenser and the brackets. Also check to make sure the foam or rubber pipe insulation completely covers the pipes.