In May I had a new Carrier Infinity system installed:
AC 2 SPD 38 TDB0483
Aerosealed the ducts
in my 2,200 sq ft mid-1960's 3 bedroom ranch home. The home is well shaded by old growth trees, located in the Chicago suburbs. Attic has R38 insulation. Ducts are insulated sheet metal, size 16x20 with static pressure of .43 after Aerosealing Windows are old 1960's Anderson double payne WindowWalls. One skylight and 2 solar tubes.
The problem is high humidity. The Infinity controller continually shows 60%-65% humidity even though it perfectly maintains 72F no matter the outdoor temp. To keep humidity around 50% I run a 50 pint portable dehumifier in the house that collects about 1.5 to 2 gallons of water every 24 hours.
The Infinity system is excellent other than this. It is nice and quiet, and vary rarely runs on high. I am hoping for better humidity control, if possible.
Is a whole-house dehumifier the answer? Is it the shady trees that don't let the system run long enough?
For whatever its worth, I believe the installer said he set the AC for "efficiency"