Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
You did not do anything wrong. What these messages are telling you is that you specified sizing information (i.e,. those inputs that can be autosized by the program) that is different from what the simulation calculated.
You must have included sizing objects in your input file, for example Sizing:Zone, Sizing:System and Sizing:Plant.
You also must have told the simulation to execute a sizing run in the SimulationControl object:
SimulationControl,
Yes, !- Do Zone Sizing Calculation
Yes, !- Do System Sizing Calculation
Yes, !- Do Plant Sizing Calculation
Yes, !- Run Simulation for Sizing Periods
Yes; !- Run Simulation for Weather File Run Periods
When the input file is set up this way, these messages will show up when you hard-size equipment so that you can see if your inputs match, or closely match, the simulation results. It's OK to provide your own data, but at times the information may not be accurate with respect to the simulation (e.g., lighting/equipment loads are off from the actual building, infiltration/ventilation is different from the actual building, etc.). Given this information you can investigate why these data are different.
You can turn these messages off by setting to No the Do xxxx Sizing Calculation input in the SimulationControl object.
Regarding the condenser water flow rate difference, the Engineering Reference shows the calculation for Design Condenser Volume Flow Rate (V8.8, section 10.7.17.3, pg 539 - or search for "Design Condenser Volume Flow Rate"). You can review the Eng. Ref. for any of the objects in E+ to see how those models calculate sizing data.
