Hi All,
It seems important to this discussion that the way the Energy Plus defines ?Airflow-First? and ?Temperature-First? seems to be exactly the opposite of how e-Quest does.

The PNNL PRM guide and the E+ Input Output Reference (refer to the SetpointManager:WarmestTemperatureFlow object) state that ?Flow-First? option ?minimizes zone reheat coil energy (or overcoling) and central chiler energy consumption at the cost of possible increased fan energy.?

Whereas, the e-Quest help states that the ?Airflow-First? option ?minimizes air flow and fan energy, at the possible expense of cooling energy?.

Looks to me that in Energy Plus, the starting point is a no load condition (min flow, and maximum SAT), as load increases, flow is FIRST increased, followed by lowering the SAT.
But in e-Quest, the starting point is full load condition (max flow, minimum SAT), as load decreases flow is FIRST reduced, followed by increasing the SAT.
Both are ?Airflow FIRST? but in the opposite sense.

The SAT reset is also implemented in different ways in the two programs.

Best,
Molly

Molly Curtz PE BEMP LEED AP BD+C
Senior Mechanical Engineer

Arup
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