Compressor noise, poor upstairs cooling w new zone system

[400E]

This spring I had my old heat pump replaced with a Lennox Elite variable-speed AC unit. (I have a Trane variable-speed furnace.) I also had a Honeywell 2-zone system put in to try to better cool my 2nd floor.

It was working OK until the last week when outdoor temps have been in the mid-90s. Now, it is only getting down to about 79 upstairs (set point 76). No trouble keeping 1st floor at its same set point of 76.

The odd thing is that i can hear when the AC kicks in that it sounds like an electric motor "spooling up" over about a minute or so as RPMs increase. Then this motor will run for a minute or two, then it will slowly reduce its RPMs over a minute or so. Within another minute or two, I'll hear the system fan kick in and cold air will start flowing.

I plan to have our HVAC company come out to check it out, but wondering in the meanwhile what this strange motor sound might be, and also wondering if the zone system can/should be tweaked to favor the 2nd floor?

I am in Omaha, Nebraska.

Thanks!

[pecmsg]

Sounds like they screwed up on the zoning to the second floor.

[vstech]

Where are the spooling sounds originating from? You could be hearing the condenser fan motor orienting itself, along with the compressor setting on a capacity.
Also, he variable speed ECM fan motors perform a startup loading sequence frequently. They oscillate forwards and back a few seconds while they determine loads, and rotational direction. That might be what you are hearing… it shouldn’t be for a few MINUTES though.

[400E]

Where are the spooling sounds originating from? You could be hearing the condenser fan motor orienting itself, along with the compressor setting on a capacity.
Also, he variable speed ECM fan motors perform a startup loading sequence frequently. They oscillate forwards and back a few seconds while they determine loads, and rotational direction. That might be what you are hearing… it shouldn’t be for a few MINUTES though.

The weird thing is that the sound seems to be coming from the basement, right inside where the lineset goes through the wall and into the basement ceiling. The outside unit sounds normal, and the air handler sounds normal.