We added the Load: Heating: Heat Pump Backup output here specifically to calculate the HP vs backup loads for a dual-fuel HP, which is needed to calculate the ERI for these systems. Now that we model HP backup usage during defrost cycles (BackupHeatingActiveDuringDefrost), the output is a bit confusing since it excludes this usage. So the electricity use of the HP backup is not really consistent with the reported load delivered by the HP backup. It also means that there is no way to calculate the COP of just the heat pump (i.e., fully excluding the backup usage).
Should we add a new output (say, Load: Heating: Heat Pump Defrost Backup)? I'm sure it would help some subset of power users get what they want, but I worry a little bit about the additional complexity/nuances for our outputs.
We added the
Load: Heating: Heat Pump Backupoutput here specifically to calculate the HP vs backup loads for a dual-fuel HP, which is needed to calculate the ERI for these systems. Now that we model HP backup usage during defrost cycles (BackupHeatingActiveDuringDefrost), the output is a bit confusing since it excludes this usage. So the electricity use of the HP backup is not really consistent with the reported load delivered by the HP backup. It also means that there is no way to calculate the COP of just the heat pump (i.e., fully excluding the backup usage).Should we add a new output (say,
Load: Heating: Heat Pump Defrost Backup)? I'm sure it would help some subset of power users get what they want, but I worry a little bit about the additional complexity/nuances for our outputs.