Stretch wrote:

If you installed two complete heat pumps to save on and speed
recovery, the added cost of the second system would be more
than the savings provided by not using any strip heat.

Yes, that's why I said it would only make sense if the extra was surplus etc.

If you installed a slightly oversized 2 stage heat pump, it would run
in low stage all summer providing about 65% total cooling capacity.
Then it would run in high stage (High Capacity) during heating season
when it was below 45 degrees outside. You could possibly set back
in this case. Note that installing a two stage heat pump usually adds
about $2,000.00 to an average installation. The average life of a quality,
properly installed air to air heat pump is 15-20 years nationally. If you
would save $2,000.00 over that time span, then install the two stage
system. If you install two complete systems, add about $6000.00 to
$10,000.00 to the cost of the first system, assuming you had room for
the extra ducts and registers and equipment.

You wouldnt need all the ducts and registered duplicated
if you just used it for the faster return from the setback temp.

Tough way to save money.

Yes, that's why I said it would only make sense if the extra was surplus etc.