Each zone would have its on zone damper and thermostat that hooks directly to the control board inside the Hydro-Temp System.  The control board would then open and close the proper dampers and turn on and off the Hydro-Temp unit.  The control board will allow for some thermostats to call for heat while others could call for cool.  The microprocessor would be programmed by the installing dealer to decide which zones have priority over other zones.  Zones with priority will open the appropriate dampers and start the Hydro-Temp system in the mode needed.  Other zone dampers will be closed.

This allows a 4 zone system to work as if it has 4 units installed.  This set up is ideal for multi-level homes or for separating bedrooms from the rest of the house.  Also used in most commercial buildings and schools.

Zone limiting is used to control which zones can run the system in high speed and which zones can only run in stage one or not at all.  You can set a small zone to only run when a larger zone is calling for the same mode (heat or cool).  With a little pre-planning a Hydro-Temp zone system can be installed in almost any home or commercial application without bypass or barometric dampers.

A wide range of thermostats exist for heat pumps and not heat pump equipment.  The Hydro-Temp microprocessor can be programmed to accept a call from either.