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Severe simulation error

asked 2017-06-16 07:54:27 -0500

map1995 gravatar image

updated 2017-06-19 07:04:50 -0500

I have been running simulations on my model frequently and all of a sudden a ton of errors have been appearing and the simulation terminates. I don't know what I changed in my DesignBuilder model to cause these errors.

The only severe error is: PsyRhoAirFnPbTdbW: RhoAir (Density of Air) is calculated <= 0 [-0.20088]. pb=[98875.00], tdb=[-1952.78], w=[1.3106801E-002]. Routine=CorrectZoneHumRat, Environment=CWRU (01-01:31-12), at Simulation time=06/29 22:00 - 22:01

Any idea what I need to adjust in my model that would get rid of this error? Thank you!

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answered 2017-06-20 05:31:30 -0500

Gio gravatar image

Can you describe you HVAC system?

I got a similar error when I missed the design air flow rate of a ASHP

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The HVAC system includes district heating and cooling, and then one air handler with 2 cooling coils. In addition, each zone has a VAV and water convector. Any suggestions?

I will look over the design air flow rates in my model.

map1995 gravatar image map1995  ( 2017-06-20 08:22:33 -0500 )edit

So I would check the coils, in particular the design air flows with m3/s unit. It's easy to miss a comma position.

Gio gravatar image Gio  ( 2017-06-20 08:31:10 -0500 )edit

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Asked: 2017-06-16 07:54:27 -0500

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Last updated: Jun 20 '17