My residential outside AC unit is making a lot of noise on the outside and also transferring noise and vibrations on the wall on the inside by where the unit's lines enter the house. It is a Lennox 13ACD-060-230-01 unit - approx. 5 years old (new with the house). I have had 2 HVAC guys look at it and they have changed out the fan motor, and tried mounts under the unit and it has not improved. The noise gets worse in the heat of the day - we are in North TX and it has been 100+ lately. It sounds to me like the compressor is making most of the noise on the outside - the HVAC guy that replaced the fan motor said it was the fan motor making the noise and it was going out, but that didn't help. The vibration noise on the inside is the bigger issue - it sounds much like the compressor noise. I was told that the lines are probably resting against either the dry wall or studs in the wall and that is the source of the noise on the inside. The best solution the HVAC guy has for that is to reroute the line on the outside of the house and up into the attic to the unit, by-passing the walls. Any better ideas out there?