Re: [EnergyPlus_Support] DX coils consistency with ASHRAE 9.1-2007 Tab6.8.1A for a Baseline VAV system 5 with reheat

The 2nd.
Â "Standard Rated Net COP [W/W]" from DX Cooling Coils table (whereÂ ANSI/AHRI ratings account for supply air fan heat and electric power).

On 14 Apr 2016 16:54, "telemar87@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

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Dear all,

I have a question about how to model correctly a VAV system 5 of a baseline model in a LEED project.
My question is about how to set the DX cooling coil COP in the object Coil:Cooling:DX:SingleSpeed.

The object is set in this form.

Coil:Cooling:DX:SingleSpeed,
Â Â Â VAV-PC-01B AHU 4 Unitary Cooling Coil DX Cooling Coil,Â !- Name
Â Â Â On 24/7,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Availability Schedule Name
Â Â Â autosize,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Gross Rated Total Cooling Capacity {W}
Â Â Â autosize,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Gross Rated Sensible Heat Ratio
Â Â Â 2.87,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Gross Rated Cooling COP {W/W}
Â Â Â autosize,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Rated Air Flow Rate {m3/s}
Â Â Â 773.300000,Â Â Â Â Â Â Â Â Â Â Â Â Â !- Rated Evaporator Fan Power Per Volume Flow Rate {W/(m3/s)}
Â Â Â VAV-PC-01B AHU 4 Mixed Air Outlet,Â !- Air Inlet Node Name
Â Â Â VAV-PC-01B AHU 4 Unitary Cooling Coil DX Cooling Coil Air Outlet Node,Â !- Air Outlet Node Name
Â Â Â DXClgCoilTotalClgCapFuncTemperature,Â !- Total Cooling Capacity Function of Temperature Curve Name
Â Â Â DXClgCoilTotalClgCapFuncFlowFraction,Â !- Total Cooling Capacity Function of Flow Fraction Curve Name
Â Â Â DXClgCoilEnergyInputRatioFuncTemperature,Â !- Energy Input Ratio Function of Temperature Curve Name
Â Â Â DXClgCoilEnergyInputRatioFuncFlowFraction,Â !- Energy Input Ratio Function of Flow Fraction Curve Name
Â Â Â DXCoilPartLoadFractionCorrelation,Â !- Part Load Fraction Correlation Curve Name
Â Â Â 0.0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Nominal Time for Condensate Removal to Begin {s}
Â Â Â 0.0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Ratio of Initial Moisture Evaporation Rate and Steady State Latent Capacity {dimensionless}
Â Â Â 0.0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Maximum Cycling Rate {cycles/hr}
Â Â Â 0.0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Latent Capacity Time Constant {s}
Â Â Â ,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Condenser Air Inlet Node Name
Â Â Â AirCooled,Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Condenser Type
Â Â Â 0.90,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Evaporative Condenser Effectiveness {dimensionless}
Â Â Â autosize,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Evaporative Condenser Air Flow Rate {m3/s}
Â Â Â 0.00,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Evaporative Condenser Pump Rated Power Consumption {W}
Â Â Â 0.000,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Crankcase Heater Capacity {W}
Â Â Â 10.00,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Maximum Outdoor Dry-Bulb Temperature for Crankcase Heater Operation {C}
Â Â Â ,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Supply Water Storage Tank Name
Â Â Â ,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Condensate Collection Water Storage Tank Name
Â Â Â 0.000,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Basin Heater Capacity {W/K}
Â Â Â 2.00,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Basin Heater Setpoint Temperature {C}
Â Â Â On 24/7;Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Basin Heater Operating Schedule Name

the DX coil should be consistent with ashrae tab 6.8.1A minimum efficiencies for example a value of COP of 2.78.

The html E+ output file report for my cooling coil 2 type of COP: the "Nominal Efficiency [W/W]" from cooling coils table (anche where Nominal values are gross at rated conditions, i.e., the supply air fan heat and electric power NOT accounted for) and "Standard Rated Net COP [W/W]" from DX Cooling Coils table (where ANSI/AHRI ratings account for supply air fan heat and electric power).

I don't understand which of these 2 COP values should be consistent with values reported in the overmentioned ASHRAE table.

Thanks,
Marco

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