This has been a long process of getting bids and information and now have a system installed and don't know if I need tuning or a replacement system. My fear is that this system is oversized for the property.

Denver Area
Home that was converted into 3 apartments
1892 two story 4 bricks thick - 1800 Sq Ft
The old porch was added on and ducts were added at some point 500 SQ ft
Once common heating forced air system in the cellar.

Displaced thermopride 162K input furnace probably 40% efficient (only saw it work briefly)
Property used to have a coal furnace years ago.
Installed RGRM-10EZAJS and RARL-049JEZ and NEST thermostat (1st floor)
Heat load document from the installer was 60K in a pie chart
APRILAIRE media filter, and bypass humidifier

1st floor two double sided heat vents 1 larger return
2nd floor, 4 heat vents (12 in round return added to this floor up high with this installation)
Rear porch apartment 500 sq ft, had two supples and not returns (added 1 return and 1 supply)

Issues:

Not sure how the selection of my unit size was determined

2nd floor is 66-67 degrees when 1st floor is 70 degrees
Addition is 66-67 degrees when 1st floor is 70 degrees
2nd floor 12" round return is LOUD (wind noise)

After installation furnace wind noise was LOUD especially the added return. I thought the benefits would be quiet operation. I asked if the blower could be slowed down. With the dip switches they changed it from 1400 CFM to 1150 CFM with of course increase in TEP rise, same BTU's. Same fan speed for 1st and 2nd stage by design.

Furnace could not be raised off the floor due to height restrictions and A/C coil. All of returns enter into the fight side of the furnace thru the filter.

My theory is this is an old house with small and few ducts from the old coal furnace and installing this size of the furnace means high CFM to cool the exchanges resulting in lots of noise. Looking at the literature seems a smaller unit could have been selected that still would have supported 4 ton blower for A/C.

Questions in my mind. Should this be downscaled to 90 or 75 K 2 stage unit
Should the returns be piped into each side of the furnace to quiet the return via another aprilaire filter
Static pressure (don't know what it is)
Do I need another supply in level 2
Would a 90K 2 stage running at 850 CFM be quiet enough
i was shooting for a well balanced system rather than a complicated three zone system with bypasses etc

Any input would be appreciated, or let me know what PICS I can supply. I have not called the installer back until I am a bit further educated here. It's not quiet or comfortable. Installation was careful, ducts all sealed, things done tidy, good reputation installer, just not sure this is sized or tuned for my application

Thanks !