Relative humidity > 100% fatal in Variable Speed DX coil model

EnergyArchmage commented 7 years ago

Issue overview

The variable speed coil model has the same problem as the multi speed model did in https://github.com/NREL/EnergyPlus/issues/6023, which was fixed with https://github.com/NREL/EnergyPlus/pull/6024. It looks like the same code was carried over from DXCoil.cc. Problem is here https://github.com/NREL/EnergyPlus/blob/develop/src/EnergyPlus/VariableSpeedCoils.cc#L6588

The outlet relative humidity is unimportant and calculated too soon, before corrections are applied to not go above saturation curve, then issues a fatal. Fix is to remove RH calculation and error trap, as was done in DXCoil.cc

Work around is to arbitrarily reduce SHR input values by about 0.02 in Coil:Cooling:DX:VariableSpeed input object.

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nealkruis commented 6 years ago

@mjwitte will this be fixed with the coil refactor?

mjwitte commented 6 years ago

If we remember, yes, but we should fix it in the current coil also so it doesn't create extra diffs. Basically the fix should go into both branches at the same time.

NREL / EnergyPlus