Air-to-water heat pump rating conditions in EnergyPlus

asked 2021-10-08 15:01:35 -0500

Hi Energy Modeler Community,

I'm in trouble with HeatPump:PlantLoop:EIR:Cooling and HeatPump:PlantLoop:EIR:Heating objects.

They are not specified neither in I/O reference nor in Engineering reference what are the standard rating conditions to which refers the Capacities and EIR previously entered and consequently what are the the couples of temperatures to which curves are expected to get the unitary value.

With reference to AHRI 551/591 (and to Chiller:Electric:EIR obj, with similar behavior to model central plantn air-cooled chiller that however admit rated conditions to be entered) I can guess:

for cooling mode (HeatPump:PlantLoop:EIR:Cooling obj)

they could refer to:

Conversely for heating mode (HeatPump:PlantLoop:EIR:Heating obj) I'm even more insecure:

they could refer:

  • water leaving: one of 40°C or 50°C or 60°C (if as per AHRI), but eventually which of the three? (no other similar obj in EnergyPlus)
  • air dry-bulb entering: 8°C or -8°C (if as per AHRI), but but eventually which of the two ?

I have the unpleasant feeling that with this object (super-useful in the intentions to cover a plant equipment nowdays widely used at least here in Europe) the modeler can completely misunderstand the performance of the plant equipment itself.

Has anyone already addressed this topic?

Could someone from the development team guide me on what the expected reference conditions are to put rated Capacities and EIR and from which start moving on curves?

Thanks to anybody will spend some time to answer or give an insight.

A.

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