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[EnergyPlus_Support] Re: How can I simulate a stuck open economizer?

Hello List.

Thanks for your advise, yes, I have read the I/ORef carefully. I think I understand how the controller:OutdoorAir works.
Following Jim's advise, to simulate an stuck open Outdoor Air damper, I am setting up the Controller:Outdoor Min and Max OA Flow Rates (in m3/s) slightly less than the Autosize values that I found (thanks Linda) in the eio file.

When I run the simulation, though, now I'm getting four warnings telling me that E+ cannot reach a solution to the system of equations. This is part of one of the warnings;
   ** Warning ** SimHVAC: Maximum iterations (25) exceeded for all HVAC loops, at BEIJING - CHN IWEC Data WMO#=545110, 07/07 17:30 - 17:40
   **   ~~~   ** SimFlags=[TFFFF] AirLoops[T],ZoneEq[F],NonZoneEq[F],PlantLoops[F],ElecCircuits[F]..F=ok,T=fail
   **   ~~~   ** Plant Tolerance Flags=[10000000] Enthalpy[1],MassFlow[0],HumRat[0],Pressure[0],FlowQual[0],Energy[0],Temp[0],PlantFlowMassFlow[0]..0=ok,1=fail
   **   ~~~   ** Plant EnthalpyTol=718.958, MassFlowTol=0.000, HumRatTol=0.0000, PressureTol=0
   **   ~~~   **      FlowQualTol=0.00, EnergyTol=0.000, TempTol=1.35E-003

Note that the warnings are at the peak of the summer. For this reason, I thought that the tower could not handle the extra load of the hot and humid OAir. So, I increased the tower water flow capacity, but it did not help.

Any idea how to trace this problem?

Thanks.

Homero.

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Jean marais" <jeannieboef@...> wrote:
>
> Watch out! Read very carefully the object section on the Controler for ODA in the ioRef. Some fields override or take the maximum of others. Be careful of default setting also in fields you are not planning to use. This can be a tricky object and it includes the control of the economizer action. 
> 
> I stand corrected, but as I understand it "econimizer" means a control methodology of the Mixing Damper in the "Umluftkammer" of an AHU (in e+ this is the mixing box). If the damper is jammed open, you have only circulating air. If the damper is jammed closed you have a dedicated outdoor air system without mixing.
> 
> I've not seen an AHU with a 3rd duct to outside serving as an extra intake.
>



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