The multispeed coil can be a little testy at times.
For one thing, the multispeed parent object is trying to control the system performance by iterating on an operating point. During this iteration process, the coil model is called to report it's output, since it's this output that the parent object is iterating on. If the parent object doesn't guess right the first time, it's likely, maybe that's not the best choice of words, that the coil will have issue with the air flow rate and coil PLR that the parent object chose. The coil model does not currently know that a parent is iterating and throws warnings anytime an issue is found, even if that warning occurs at an iteration point that is far from the correct answer. That's the best explanation I can give without delving into your actual performance using your input file.
I find it interesting that on 1/26 at 15:40 the outlet air temp from the cooling coil is -21.76C. I would report using the detailed frequency and look at the supply air temperature and humidity ratio leaving the cooling coil (i.e., system node temp and humrate). I suspect you will not find this temperature which means that the cooling coil is reporting a warning that is not actually happening. If you do see temps this cold in the output file, I would re-think the inputs for cooling performance.
On 7/8/2014 8:41 AM, Julien Marrec
julien.marrec@xxxxxxxxx [EnergyPlus_Support] wrote:
Hi,
Could anyone give me pointers as to what those errors really mean and where to start to fix them please?
** Warning ** Calculated Relative Humidity out of range (PsyRhFnTdbWPb)
** ~~~ ** Routine=CalcMultiSpeedDXCoil:lowspeedoutlet, Environment=Newark International Arpt NJ USA TMY3 WMO#=725020, at Simulation time=01/26 15:30 - 15:40
** ~~~ ** Dry-Bulb= -21.76 Humidity Ratio= 5.368E-004 Calculated Relative Humidity [%]= 101.36
** ~~~ ** Relative Humidity being reset to 100.0%
I'm getting a lot of these in my annual simulation, as seen in the recurring error summary.
** Warning ** Enthalpy out of range (PsyTsatFnHPb)
** ~~~ ** Routine=CalcMultiSpeedDXCoil:newdewpointconditions,
** ~~~ ** Environment=Newark International Arpt NJ USA TMY3 WMO#=725020, at Simulation time=04/13 15:40 - 15:50
** ~~~ ** Enthalpy=-44323.75813 Pressure= 102900.00
** ~~~ ** Initial Resultant Temperature= -59.98
************* ** Warning ** Calculated Relative Humidity out of range (PsyRhFnTdbWPb)
************* ** ~~~ ** This error occurred 347184 total times;
************* ** ~~~ ** during Warmup 0 times;
************* ** ~~~ ** during Sizing 0 times.
************* ** ~~~ ** Max=201.056045 % Min=101.000023 %
*************
*************
************* ** Warning ** Enthalpy out of range (PsyTsatFnHPb)
************* ** ~~~ ** This error occurred 37304 total times;
************* ** ~~~ ** during Warmup 0 times;
************* ** ~~~ ** during Sizing 0 times.
************* ** ~~~ ** Max=-42408.777137 J/kg Min=-44428.173269 J/kg
Thanks,
Julien
--LinkedIn (en) : www.linkedin.com/in/julienmarrec
Julien Marrec, EBCP, BPI MFBA
Energy&Sutainability Engineer
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-- Richard Raustad Senior Research Engineer Florida Solar Energy Center 1679 Clearlake Road Cocoa, FL 32922 Ph: (321)638-1454 http://www.fsec.ucf.edu/en/ Electric Vehicle Transportation Center http://evtc.fsec.ucf.edu/
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