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Re: [EnergyPlus_Support] Re: Regarding the problem of Cooling Coil sizing



Sensible heat ratio 3 > unity?

Mit freundlichen GrüÃ?en- Sent from my iPhone (excuse the brevity)

i. A.
Jean Marais
b.i.g. bechtold
Tel.   +49 30 6706662-23

On 23.06.2014, at 17:18, "fpasserini.tn@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

 

I get this warning even if both the "gross rated total cooling capacity" and the "rated air flow rate" are autosized, e.g.:


Coil:Cooling:DX:SingleSpeed,
    Air Loop Blocco principale:Area prep AHU/1 Unitary Cooling Coil DX Cooling Coil,  !- Name
    2,                       !- Availability Schedule Name
    autosize,                !- Gross Rated Total Cooling Capacity {W}
    autosize,                !- Gross Rated Sensible Heat Ratio
    3.00,                    !- Gross Rated Cooling COP {W/W}
    autosize,                !- Rated Air Flow Rate {m3/s}
    773.300000,              !- Rated Evaporator Fan Power Per Volume Flow Rate {W/(m3/s)}
    Air Loop Blocco principale:Area prep AHU/1 Heating Coil Air Outlet Node,  !- Air Inlet Node Name
    Air Loop Blocco principale:Area prep Supply Side Outlet 1,  !- Air Outlet Node Name
    JCI J05XP Cooling CAPFTemp,  !- Total Cooling Capacity Function of Temperature Curve Name
    JCI J05XP Cooling CAPFFF,!- Total Cooling Capacity Function of Flow Fraction Curve Name
    JCI J05XP Cooling EIRFTemp,  !- Energy Input Ratio Function of Temperature Curve Name
    JCI J05XP Cooling EIRFFF,!- Energy Input Ratio Function of Flow Fraction Curve Name
    JCI J05XP Cooling PLFFPLR,  !- Part Load Fraction Correlation Curve Name
    0.0,                     !- Nominal Time for Condensate Removal to Begin {s}
    0.0,                     !- Ratio of Initial Moisture Evaporation Rate and Steady State Latent Capacity {dimensionless}
    0.0,                     !- Maximum Cycling Rate {cycles/hr}
    0.0,                     !- Latent Capacity Time Constant {s}
    ,                        !- Condenser Air Inlet Node Name
    AirCooled,               !- Condenser Type
    0.90,                    !- Evaporative Condenser Effectiveness {dimensionless}
    autosize,                !- Evaporative Condenser Air Flow Rate {m3/s}
    0.00,                    !- Evaporative Condenser Pump Rated Power Consumption {W}
    0.000,                   !- Crankcase Heater Capacity {W}
    10.00,                   !- Maximum Outdoor Dry-Bulb Temperature for Crankcase Heater Operation {C}
    ,                        !- Supply Water Storage Tank Name
    ,                        !- Condensate Collection Water Storage Tank Name
    0.000,                   !- Basin Heater Capacity {W/K}
    2.00,                    !- Basin Heater Setpoint Temperature {C}
    2;                       !- Basin Heater Operating Schedule Name


In the .err file:
   ** Warning ** SizeDXCoil: Coil:Cooling:DX:SingleSpeed AIR LOOP BLOCCO PRINCIPALE:AREA PREP AHU/1 UNITARY COOLING COIL DX COOLING COIL
   **   ~~~   ** ...Rated Total Cooling Capacity will be limited by the minimum rated volume flow per rated total capacity ratio.
   **   ~~~   ** ...DX coil volume flow rate (m3/s) = 0.159839
   **   ~~~   ** ...Requested capacity (W) = 4088.447
   **   ~~~   ** ...Requested flow/capacity ratio (m3/s/W) = 3.909E-005
   **   ~~~   ** ...Minimum flow/capacity ratio (m3/s/W) = 4.027E-005
   **   ~~~   ** ...Adjusted capacity (W) = 3969.206

Is it acceptable?
Regards



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Posted by: "jeannieboef@xxxxxxxxx" <jeannieboef@xxxxxxxxx>


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