Setpoints and related data
The setpoints and related data include the following items:
- Heating Control Type (Htg-Type) Proportional
- Hydronic Heating Stage #1 Supply Air Setpoint (HydH1SA-Sp)
- Hydronic Heating Stage #2 Supply Air Setpoint (HydH2SA-Sp)
- VAV Supply Air Temp Reset Setpoint (SATRst-Sp)
- Hydronic Heat Valve Reverse Acting (HydReverse)
- VAV Operating Heating Setpoint (VAVOprHtg-Sp)
- Hydronic Heat Valve % Command (HWV)
Operation
If the supply air temperature is lower than the VAV Operating Heating Setpoint, the Hydronic Heat Valve % Command modulates open. If the supply air temperature is greater than the VAV Operating Heating Setpoint, the Hydronic Heat Valve % Command modulates closed. The rate of change for Hydronic Heat Valve % Command is limited to 30% per minute.
The VAV Operating Heating Setpoint is determined using the VAV Supply Air Temp Reset Setpoint, Hydronic Heating Stage #1 Supply Air Setpoint, and Hydronic Heating Stage #1 Supply Air Setpoint. When the difference between the VAV Supply Air Temp Reset Setpoint and the Operational Space Temperature is less than or equal to 2°F, VAV Operating Heating Setpoint is equal to Hydronic Heating Stage #1 Supply Air Setpoint; otherwise VAV Operating Heating Setpoint is equal to Hydronic Heating Stage #2 Supply Air Setpoint.
Hydronic Heat Valve Reverse Acting allows support for either normally open or normally closed valves.