[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [EnergyPlus_Support] Warnings in the HVAC simulation




It depends what you are testing. I typically put all the other zones on a different system. I also leave the test zone's AHU componants on autosize. I only consider usage energy and not AHU or other plant operating energy consumptions, because they don't refect the economies of scale.
No one said this job is easy. :-)

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 16.05.2014, at 16:54, "<mailto:luca.guj@xxxxxxxxx>luca.guj@xxxxxxxxx [EnergyPlus_Support]" <<mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx>EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

>  
Hi Jean,

> 
> first of all thanks. I have corrected my model as follows:
> Sizing:System,
    Air Loop HVAC 1,         !- AirLoop Name
    VentilationRequirement,  !- Type of Load to Size On
    autosize,                !- Design Outdoor Air Flow Rate {m3/s}
    1,                     !- Minimum System Air Flow Ratio
    7,                       !- Preheat Design Temperature {C}
    0.008,                   !- Preheat Design Humidity Ratio {kgWater/kgDryAir}
    12.8,                    !- Precool Design Temperature {C}
    0.008,                   !- Precool Design Humidity Ratio {kgWater/kgDryAir}
    12.8,                    !- Central Cooling Design Supply Air Temperature {C}
    16.7,                    !- Central Heating Design Supply Air Temperature {C}
    NonCoincident,           !- Sizing Option
    Yes,                     !- 100% Outdoor Air in Cooling
    Yes,                     !- 100% Outdoor Air in Heating
    0.0085,                  !- Central Cooling Design Supply Air Humidity Ratio {kgWater/kgDryAir}
    0.008,                   !- Central Heating Design Supply Air Humidity Ratio {kgWater/kgDryAir}
    DesignDay,               !- Cooling Design Air Flow Method
    0,                       !- Cooling Design Air Flow Rate {m3/s}
    DesignDay,               !- Heating Design Air Flow Method
    0,                       !- Heating Design Air Flow Rate {m3/s}
    ZoneSum;                 !- System Outdoor Air Method
> Sizing:Zone,
    1 Concrete Coated,       !- Zone or ZoneList Name
    SupplyAirTemperature,    !- Zone Cooling Design Supply Air Temperature Input Method
    14,                      !- Zone Cooling Design Supply Air Temperature {C}
    ,                        !- Zone Cooling Design Supply Air Temperature Difference {deltaC}
    SupplyAirTemperature,    !- Zone Heating Design Supply Air Temperature Input Method
    40,                      !- Zone Heating Design Supply Air Temperature {C}
    ,                        !- Zone Heating Design Supply Air Temperature Difference {deltaC}
    0.0085,                  !- Zone Cooling Design Supply Air Humidity Ratio {kgWater/kgDryAir}
    0.008,                   !- Zone Heating Design Supply Air Humidity Ratio {kgWater/kgDryAir}
    DemonstratorSpecOutdoorAir,  !- Design Specification Outdoor Air Object Name
    ,                        !- Zone Heating Sizing Factor
    ,                        !- Zone Cooling Sizing Factor
    DesignDay,               !- Cooling Design Air Flow Method
    0,                       !- Cooling Design Air Flow Rate {m3/s}
    0.000762,                !- Cooling Minimum Air Flow per Zone Floor Area {m3/s-m2}
    0,                       !- Cooling Minimum Air Flow {m3/s}
    0,                       !- Cooling Minimum Air Flow Fraction
    DesignDay,               !- Heating Design Air Flow Method
    0,                       !- Heating Design Air Flow Rate {m3/s}
    0.002032,                !- Heating Maximum Air Flow per Zone Floor Area {m3/s-m2}
    0.1415762,               !- Heating Maximum Air Flow {m3/s}
    0.3,                     !- Heating Maximum Air Flow Fraction
    1 Concrete Coated Design Spec Zone Air Dist;  !- Design Specification Zone Air Distribution Object Name
> We this configuration I get much better result in terms of energy consumption which are much closer to the experimental data which I actually have measured. But I still get many warnings like before:
> Warning ** CalcDoe2DXCoil: Coil:Cooling:DX:SingleSpeed="OS:COIL:COOLING:DX:SINGLESPEED 4 ALUMINUM NON COATED" - Air volume flow rate per watt of rated total cooling capacity is out of range at 2.046E-005 m3/s/W.
  ~~~   **  Environment=RUN PERIOD 1, at Simulation time=01/01 08:15 - 08:30                                         ~~~   ** Expected range for VolumeFlowPerRatedTotalCapacity=[2.684E-005--6.713E-005]                     ~~~   ** Possible causes include inconsistent air flow rates in system components,      
> Warning ** CalcDoe2DXCoil: Coil:Cooling:DX:SingleSpeed="OS:COIL:COOLING:DX:SINGLESPEED 4 ALUMINUM NON COATED" - Air volume flow rate per watt of rated total cooling capacity is out of range error continues.
  ~~~   **   This error occurred 15498 total times;                                                                                       ~~~   **   during Warmup 0 times;                                                                                                           ~~~   **   during Sizing 0 times.                                                                                                               ~~~   **   Max=2.178820E-005  Min=2.021210E-005                                                                                 
> I think that i have understood why I get these warnings: the 4 zones that i'm studying don't have any load, i.e. people, equipment....., in fact they are experimental setups, therefore E+ is not performing the sizing and is using the sizing performed for the huge building also included in the model. So How do I solve this issue??
> Warning ** Calculated design heating load for zone=1 CONCRETE COATED is zero.     
  ~~~   ** Check Sizing:Zone and ZoneControl:Thermostat inputs.                   
Warning ** Calculated design heating load for zone=2 CONCRETE NON COATED is zero. 
  ~~~   ** Check Sizing:Zone and ZoneControl:Thermostat inputs.                   
Warning ** Calculated design heating load for zone=3 ALUMINUM COATED is zero.     
  ~~~   ** Check Sizing:Zone and ZoneControl:Thermostat inputs.                   
Warning ** Calculated design heating load for zone=4 ALUMINUM NON COATED is zero. 
  ~~~   ** Check Sizing:Zone and ZoneControl:Thermostat inputs.                   

I have a attached the file in case you want to give a try.                                                                                                                         
Thanks in advance for your support.
> Luca Guj
> 
> 

> <Dubai12_RealAC_Tuning1_26_32_22.idf>


__._,_.___

Primary EnergyPlus support is found at:
<http://energyplus.helpserve.com>http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx

The primary EnergyPlus web site is found at:
<http://www.energyplus.gov>http://www.energyplus.gov

The group web site is:
<http://groups.yahoo.com/group/EnergyPlus_Support/>http://groups.yahoo.com/group/EnergyPlus_Support/

Attachments are currently allowed but be mindful that not everyone has a high speed connection.  Limit attachments to small files.

EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.


<http://geo.yahoo.com/serv?s=97476590/grpId=3387488/grpspId=1705007389/msgId=31958/stime=1400261417>

<https://groups.yahoo.com/neo/groups/EnergyPlus_Support/info;_ylc=X3oDMTJlZ2Qzdmc0BF9TAzk3MzU5NzE0BGdycElkAzMzODc0ODgEZ3Jwc3BJZAMxNzA1MDA3Mzg5BHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTQwMDI2MTQxNw-->Visit Your Group
* <https://groups.yahoo.com/neo/groups/EnergyPlus_Support/members/all;_ylc=X3oDMTJmZHJzbmNlBF9TAzk3MzU5NzE0BGdycElkAzMzODc0ODgEZ3Jwc3BJZAMxNzA1MDA3Mzg5BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzE0MDAyNjE0MTc->New Members 5
<https://groups.yahoo.com/neo;_ylc=X3oDMTJkNnRvamdzBF9TAzk3NDc2NTkwBGdycElkAzMzODc0ODgEZ3Jwc3BJZAMxNzA1MDA3Mzg5BHNlYwNmdHIEc2xrA2dmcARzdGltZQMxNDAwMjYxNDE3><http://l.yimg.com/ru/static/images/yg/img/email/new_logo/logo-groups-137x15.png>
? <https://info.yahoo.com/privacy/us/yahoo/groups/details.html>Privacy ? <mailto:EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx?subject=Unsubscribe>Unsubscribe ? <https://info.yahoo.com/legal/us/yahoo/utos/terms/>Terms of Use
__,_._,___