RE: [EnergyPlus_Support] Variable Refrigerant system

[RRaustad@xxxxxxxxxxxx]

You forgot to include the fan energy. Crankcase heater energy is also a
missing component as is evaporatively cooled condenser pump power if
you are using these options.

Zone Terminal Unit Cooling Electric Consumption
Zone Terminal Unit Heating Electric Consumption (for all zones)

These are the parasitics related to the terminal unit's parasitic
inputs and depends on which mode (cooling or heating) the system is
currently operating in.

ZoneHVAC:TerminalUnit:VariableRefrigerantFlow,
 30, !- Zone Terminal Unit On Parasitic Electric Energy Use {W}
 20; !- Zone Terminal Unit Off Parasitic Electric Energy Use {W}


Variable Refrigerant Flow Heat Pump Cooling Electric Consumption
Variable Refrigerant Flow Heat Pump Heating Electric Consumption

These should provide the outdoor unit electric consumption. Adding
these should give the total outdoor unit electric consumption over the
year.

Variable Refrigerant Flow Heat Pump Electric Defrost Consumption (

The is the electric consumption due to defrost. After reviewing the
code, I am not exactly sure if this is included in Variable Refrigerant
Flow Heat Pump Heating Electric Consumption since the calculation of
defrost energy is indirectly included in total electric consumption as
a fraction of energy use. I do see that defrost electric consumption is
included in the operating COP calculation which infers it is a seperate
energy use calculation.

Carefully review the sum of all inputs to the model (fan + terminal
unit parasitics + outdoor unit electric consumption + defrost + evap
condenser pump + basin heater electric consumption)




On Fri, 07 Dec 2012 19:34:47 +0000 rikards2342 <migue885@xxxxxxxx>
wrote:
> Dear community, I simulated a variable refrigerant system with 8
> AirConditioner:VaribleRefrigerantFlow (8 external units) and a lot of internal
> units. The simulation results are correct, but I want to know the individual
> electric consumption of each external unit and in the html table only appears
> the total consumption of all HVACs (section end uses, heating and cooling).
> I tried to sum (using output:variable results in excel) the following items:
> 
> - Zone Terminal Unit Cooling Electric Consumption 
> - Zone Terminal Unit Heating Electric Consumption (for all zones)
> - Variable Refrigerant Flow Heat Pump Cooling Electric Consumption
> - Variable Refrigerant Flow Heat Pump Heating Electric Consumption
> - Variable Refrigerant Flow Heat Pump Electric Defrost Consumption (for all
> external units)
> 
> But the sum of these parameters isn't the same that the sum of the heating and
> cooling electricity given in the html results table. The difference is very
> small.
> 
> Anyone knows which is the parameter I don't take into account?
> 
> Thank you very much in advance!
> 
> ------------------------------------
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> 
> 


------------------------------------

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