Question-and-Answer Resource for the Building Energy Modeling Community
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1) It will take more digging into the results to find the answer your looking for. These SPMs all set a temperature at the control node. Flow is not set by the Warmest FlowFirst manager, temperature is, which influences the request for flow by the zone terminal units. The documentation could have been a little more clear on that. What the Warmest and Warmest FlowFirst SPMs attempt to do is set the warmest zone terminal unit damper position to 1 while all other zones will have a damper position < 1. Damper position will affect how much reheat is needed.
Since these are cooling mode managers, the control node should be at the outlet of cooling coils only. Assuming the maximum zone air flow rate and min/max SAT are the same among these SPMs, then Warmest would have the highest SAT while Warmest TempFirst would have the lowest (with higher reheat requirement). I would think that Warmest FlowFirst would have similar results as Warmest since they both act to force zone air flow rate to the highest value. Your results indicate otherwise so I would be suspicious of these results.
I would look at the resulting zone temperature histograms from these runs. Also see how outdoor air loads (flow rate) change between these scenarios. It would also be nice to see a comparison of control node set point temperatures, supply air flow rates, damper positions, and reheat quantity.
Heat rejection did not change here so I wonder what heat transfer that variable represents.
2) I can only think of one reason to choose Warmest TempFirst and that would be humidity control. A histogram of zone relative humidity will show how these managers control latent loads. One reason I can think of to include TempFirst and FlowFirst as control types would be to switch between the two SPMs (Warmest and WarmestTemperatureFlow) without actually having to change objects (i.e., you can change between Warmest and Warmest TempFirst simply by changing the control type.
I would be interested in seeing more results to get a better idea of what is happening here.
