I see many references in the forum about multi-zoned systems.  Are they all created equal?

I have a 2-zone HVAC system, 1 for each floor.  Each floor has a thermostat.  The supply ductwork splits into 2 trunks just outside the plenum, 1 for each floor.  There is an electically controlled damper in each trunk.  Each damper opens or closes depending on which thermostat (or neither or both) is calling for supply.  Note the return duct(s) are all common and there is no dampers in them.

I find this system disapointing.  In heating season (I'm heat-centric) I try to keep the lower floor 3 - 4 degrees cooler than the upper floor and it achieves that, but given physics that's pretty easy.  In cooling season I try to keep both floors the same and it fails.  Physics beats it and the lower floor is always uncomfortably cold.

Question:  are there other types of "zone" control, what are they & how do they work.  What's been your experience?

P.S. I just switched from propane to river source heat pump but I don't know if the HVAC type has anything to do with the question.

Thanks

Zoning can generally only achieve relatively small temperature differences between zones, and can't overcome physics such as a large open stairwell or entry foyer down which cool air sinks.

In your situation I'd determine of the lower floor damper is closed completely when not being called by stat. Next might be to examine return air flows - if downstairs is overly favored cool air upstairs may be sucked downstairs into its returns

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