Has anyone had any experience with setting up a multi zone HVAC? I have a 2 story, so to keep the upstairs cool, the A/C has to be cranked low - freezing downstairs and marginally cool upstairs. I found some zone controllers and dampers at RCS An A/C rep quoted me $2500 to set up, but I found the parts for about $500 if I do it myself. Any suggestions would be appreciated.