I am in the middle of choosing 2200 sf zoned system, dual fuel.
Seems carrier offers the only zoning control that takes control of blower speed, 2 speed hp, and MARDs to vary each component based on load and SP. As explained to me, all of this is done fairly dynamically, e.g., depending on outside temps, weekly experience, and changing calls from different zones.
Lennox iHarmony seems close, but it does not seem to take control of MARDs to vary airflow based on the other vaRIABLES. It just doesn't have the logic to handle this.
Trane, whose equipment I am using in a second system, does not seem to be able to work without a bytpass without using some "kluge" techniques (from the software world) by using additional sensors, etc. The Trane does not seem to be able to dynamically balance the MARDs based on demand, outside temps, etc., etc. Of course, they are about to introduce trully VS condensers and fans.
I will be using 18 HP, and VS Furnace. Efficiency TBD. Located in Atlanta, the hi-efficieny HP's can cover most of the heat load (except for about perhaps 10 days per season). At most, I expect the furnace to operate in Stage 1 except for a few times a year.
Any intel about rolout of well-tested zoning technology by Trane, carrier or Lennox would be appreciated. It is a 22 yr old system we are replacing, though we are not pressured because the furnace just keeps on running...
, albeit at some low efficiency.
THANKS!