Just delete this line. this_comp.TypeOf is set above (line 892) to the string used in the branch input, which is "HeatPump:AirToWater".

indeed. I just removed this.

Delete.

removed here too

This check for TypeOfWaterLoop will fail is the user does not specify the "Water Loop Type" in the PlantLoop object. Given it's the last field, it's likely most users/interfaces will let it default to "None". Is there a check somewhere to throw a severe error and inform the user?

PlantLoop,

  A19;  \field Water Loop Type
        \type choice
        \key HotWater
        \key ChilledWater
        \key None
        \default None

I tested one of the AHWP files with the Water Loop Type field removed, this happens:
** Fatal ** Plant component "HEATPUMP:AIRTOWATER" was not assigned a pointer.

It should be possible to check the TypeOfWaterLoop in HeatPumpAirToWater::oneTimeInit after PlantUtilities::ScanPlantLoopsForObject returns this->loadSidePlantLoc. But I don't see ScanPlantLoopsForObject there, like the other oneTimeInit functions in PlantLoopHeatPumpEIR.

Oh, I see, HeatPumpAirToWater::oneTimeInit calls EIRPlantLoopHeatPump::oneTimeInit. So you should be able to check the loop types there and throw error messages. Ideally you shouldn't need that to be set on the PlantLoop, but I don't see a way around it with the current object structure.

make sense, I added the error check in the EIRPlantLoopHeatPump::oneTimeInit function

@mjwitte @yujiex
Is this new AWHP intended to be able to provide both heating and cooling on a condenser loop? If so, shouldn't the new "Water Loop Type" field have a "CondenserWater" or "HeatingAndCooling" option? That would align with the Sizing:Plant object type offering a "Condenser" option for its Loop Type input field.

For now it only allows either heating or cooling on the plantloop, as it need to use this field to identify if the internal component is the heating one or the cooling one. Note that the object internally still has a heating component and a cooling component, using the same type of data structure as the plantloop heat pumps.
If later on the object is refactored into separate heating/cooling component, it should be able to allow this. But currently not yet. @aaron-boranian

I can try to see if there's a way to alter the internal logic to tell the internal ones apart (will create a separate PR for this) when they're on the same loop, but I don't think we can add another option like "HeatingAndCooling" as idd can't change right now. We might need to use the "None" option for now.

If I'm following correctly, this PlantLoop field for "Water Loop Type" is only used to help identify the two sides of this heat pump (which shouldn't really be necessary, because the hot water and chilled water node names are known). So hopefully this field (and the limitations) can go away in the next release.

What's this?

Oh, I see, for this table:

This will have to be ok for now, but take out the \n. It's fine for humans but may trip up software that's reading the tables.

is replacing "\n" with a space be okay? If I don't put anything there, the AWHPHeating will stick together.

@yujiex The error check works, but this heat pump does not have "load and source sides". Suggest:
"The Hot Water nodes must be connected to a HotWater loop. The Chilled Water nodes must be ChilledWater loop." It seems you could check each side for the correct loop type? I'm still not sure why this is needed, but that can stay for now.

BTW Plantloop, Water Loop Type is not described in the I/O Reference. How is it used? When was it added?

Thanks. I updated the error message.

The loop types are used to determine the two component is heating or cooling.
Previous component as they have different object type, like xx:heating and xx:cooling, the plant loop scan can tell them apart, but without that information, the plant loop type need to be used to tell them apart.

I just added some description in the IO reference.

If I'm following correctly, this PlantLoop field for "Water Loop Type" is only used to help identify the two sides of this heat pump (which shouldn't really be necessary, because the hot water and chilled water node names are known). So hopefully this field (and the limitations) can go away in the next release.