Why does airflow network crashes when changing the WPC type from Input to Av.Surface calculation

asked 2016-12-21 04:07:10 -0600

Juliatorrubia gravatar image

updated 2016-12-21 12:47:40 -0600

Hello everybody,

I'm running some tests about cross ventilation to see if it is worthy to use Airflow network in Grasshopper. I am comparing the results of AFN with simple openings with the simple calculation of room air and IES.

I am testing a shoebox of 15x5m, 3m height, 2 windows of 1sqm, only 1 person of internal gains, no heating, no cooling, basically nothing. Grasshopper version August-27, 2014. Honey bee Version 0.0.60. Energy plus version 5.

The tests were running fine with the "Wind pressure coefficient type" as Input on the AFN simulation control. But, as the number of ach that I was obtaining was tiny (approx. 1/6 of the ach of room air) I thought that the problem could be the Input and my wind pressure coefficient calculations. Therefore, I changed the WPCoefficient type to "Average surface calculation" and I deleted all the wind pressure elements.

As soon as I change this (and only this) the simulation crashes because of the error "DualSetPointWithDeadBand: Unanticipated combination of heating and cooling loads - report to EnergyPlus Development Team"  And also, my heating set point changes from -100 degrees to 12.

I've look for this in the bigladder manual for energy plus and looks like if I had set a thermostatic zone control on dual set point with dead band, what I haven't, because, to be honest, I didn't even know it existed.

I hope any of you can help me, because I've been trying hard, but I don't find which is the problem.

Thanks a lot

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