On Thu, 14 Aug 2014 20:46:20 -0700 (PDT), wrote:

But, if done properly, would you ever actually see the second damper?

No. All ductwork will be inside the cabinets.

I did find a nonmetallic thermal break to put in the ductwork. I can buy 2"
of this 10" PVC pipe for a few dollars:
http://flexpvc.com/cart/agora.cgi?pr...-DUCT-Thinwall

Don. www.donwiss.com (e-mail link at home page bottom).