I am working on a project that will have a 5 ton heat pump system with 5 to 6 zones on it. The costumer would like to have a 2nd 5 ton system installed and connected to the same duct system as a back up. I know I can connect them together as far as the duct work goes by using back draft dampers. However, I'm not sure what additional controls I would need to connect them the zone control. We only want one unit to run at a time.
Does any one have any ideas?
Thanks,
Jimmy