Chris,
sorry for the lack of information. The "low zone" serves floors 2 to 21 and the "high zone" serves floors 22 to 41. The existing system is a reverse return.
Currently working on a renovation to a 40-story building which has a low and high zones for the HVAC hydronic piping. The client rep would like to install a single zone. Does anyone have experience with this type of zoning? We prefer to maintain the existing zoning.