1 or 2 zone heat pump question

[KCinSC]

Hi all,

My two Amana heat pumps have gasped their last breaths so it's time to replace them. I have had an energy audit and two estimates so far but I have a question.
One contractor suggested that I remove both units and replace them with one larger unit as well as all new ductwork. My impression is that two zones are more efficient than one, as well as being percieved as more desireable for comfort and resale.
The initial cost difference is about $3,000.00 so I doubt I would see a break- even point for some time.
My house is a single story, 2400 sq ft on a crawl space.
Any thoughts on this are appreciated.

[t527ed]

if the house is already ducted for 2 systems i would keep it that way as long as ducts are properly sized and in good shape.

[KCinSC]

From what my second contractor told me, the ducts are sized properly. The problem is that the previous owner had several puppies under the house (how that happened, I don't know!) and they tore the insulation off of some of the ducts as well as pulled them down. There may even be some tears in the ducts themselves. The second contractor quoted for two zone and said he would make any necessary repairs to the existing ductwork. Is there a general lifespan for ductwork? Mine is original, over 20 years old.
Thanks!

[beenthere]

No set lifespan.

I would stay with 2 units.