mmm perhaps the energyplus check is too conservative? The UA of the coil will be based on NTU method corrolations. These in turn will reflect physical coil features and materials used in the studies that proposed those corrolations. It's good but not perfect. Could you try a more detailed coil model object to get closer? One size fits all possibly doesn't fit all. Do your efficiency curves deviate strongly from the default curves?
Mit freundlichen Grü�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, !- Name2, !- Availability Schedule Nameautosize, !- Gross Rated Total Cooling Capacity {W}autosize, !- Gross Rated Sensible Heat Ratio3.00, !- 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 NameAir Loop Blocco principale:Area prep Supply Side Outlet 1, !- Air Outlet Node NameJCI J05XP Cooling CAPFTemp, !- Total Cooling Capacity Function of Temperature Curve NameJCI J05XP Cooling CAPFFF,!- Total Cooling Capacity Function of Flow Fraction Curve NameJCI J05XP Cooling EIRFTemp, !- Energy Input Ratio Function of Temperature Curve NameJCI J05XP Cooling EIRFFF,!- Energy Input Ratio Function of Flow Fraction Curve NameJCI J05XP Cooling PLFFPLR, !- Part Load Fraction Correlation Curve Name0.0, !- 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 NameAirCooled, !- Condenser Type0.90, !- 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 Name0.000, !- Basin Heater Capacity {W/K}2.00, !- Basin Heater Setpoint Temperature {C}2; !- Basin Heater Operating Schedule NameIn 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) = 3969.206Is it acceptable?Regards
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