Brands and zoning

[nathan9999]

Reading many of the posts from HVAC professionals have mad me aware that the experience of the contractor and the quality of the installation is as or more important than the brand of the equipment (although some seem to have a problem with Goodman).
Couple of questions:
1. Assuming I've satisfied myself that the contractors are equally qualified and their references support a quality reputation, what about brands then? Around here everybody raves about Trane, but my understanding is that American Standard is built by the same company. So, is there some way for a consumer to know what equipment brand is better than another, or are all the major brands equally good?
2. One contractor has recommended a 4 ton Trane 19 SEER system with 3 zones for the 3139 sq ft house I am building. The architect calls for a 2-unit system totaling 6.5 tons. Any comments or suggestion as to how I might evaluate the zoned system?

Thanks very much for any assistance you might be able to provide. As an accountant with no building knowledge this forum has been very helpful in getting me to the point that I can ask intelligent questions instead of just "How much and how many tons?

[thehumid1]

I HAVE NO WAY TO KNOW IF SIZING IS CORRECT BUT YOU ARE BETTER OFF WITH A 2 UNIT SETUP:

1)MORE ENERGY EFFICIENT THAN A ZONED ONE SYSTEM SETUP.

2)WHEN 1 UNIT BREAKS DOWN YOU STILL HAVE A/C IN PART OF THE HOME.

[beenthere]

6.5 tons might be a bit over sized,(on a new house) but 2 systems are nicer then one in many situations.

Ask your contractor about, using 2 systems.
1 with 2 zones, and the as its own zone.

[jrbenny]

Originally posted by nathan9999
The architect calls for a 2-unit system totaling 6.5 tons.

I haven't seen an architect recommended system that is properly sized. Which one did the room-by-room load calculation and the duct design? That will determine the properly sized system(s).

As for zoning by multiple systems or zoning controls, they both have their merits. If you have a basement in the mix, I'd recommend multiple systems. Too often, the basement needs heat when the rest of the house needs cooling. A single system with zoning controls will struggle to keep the house comfortable on all levels in my climate.