Perhaps not relevant to the conversation, only as info. I have no whine in my new Penguin II Heat Pump Ducted High Capacity.
I installed a replacement Penguin II High Capacity for our failed 13,500 heat pump Penguin II last September.
After tweaking my front duct insulation separating the cooled air and return air, I measured the noise results for our new front unit vs our old bedroom 13,500 btu Penguin II (that still works after 21 years).
On the High Cool setting, both units had identical DB, 63 db average.
On the Low Cool setting the front unit was 1db louder than the rear unit at 62db.
As you can see, there was not much db difference between high and low cool on either unit. My rear unit has a medium setting, but the front does not.
The above readings are likely affected by the front mounted Generator running while powering the AC units.
With no AC running the generator produced a 51db reading in the salon vs 24db with nothing running.
The absolute numbers are probably suspect because I was using a calibrated phone app on my Galaxy S3.