[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [EnergyPlus_Support] Problem with UpdateZoneSizing: Heating supply air temperature
That looks right. The thing to understand is that e+ will always expect the heating system to be an air system. If, like the americans, you use hot air to heat your zones, then you need really hot air. If the deltaT between the supply air and the zone air is small, you will require a very large amount of air to heat the zone. That is the reason for the warning.
In europe we don't try and heat the zone with air from the AHU. All that the AHU does is bring the air to the comfort temperature. The equipment that does the zone heating or cooling is in the zone. That way we minimize the amount of air that needs to go through the ducts, and these systems are often without any recirculation of air (DOAS).
In e+ the sizing:plant object takes the information from the sizing:zone object and uses it to not only size the AHU componants, but also the air distrubution units (ADUs) like the VAV terminal dampers and reheat coils. sizing:plant will size everything to meet the entire zone load, unless you tell it that it should only size to meet the ODA requirements of the zones. There is another work around to have the same effect for sizing on sensible loads, but I won't mention it here to avoid confusion.
It looks like the warning remains, but now you understand why and can safely ignore it.
2014-05-01 14:26 GMT+02:00 Marco Aldegheri <<mailto:m.aldegheri@xxxxxxxxx>m.aldegheri@xxxxxxxxx>:
> Â
> And i forgot...
>
> DesignSpecification:OutdoorAir,
>    P0:P0%A1Zn2r Design Specification Outdoor Air Object, !- Name
>    Flow/Person,            !- Outdoor Air Method
>    0.010000,               !- Outdoor Air Flow per Person {m3/s-person}
>    0.000000,               !- Outdoor Air Flow per Zone Floor Area {m3/s-m2}
>    0.002759,               !- Outdoor Air Flow per Zone {m3/s}
>    0.000000,               !- Outdoor Air Flow Air Changes per Hour {1/hr}
> Â Â Â 2;Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Outdoor Air Flow Rate Fraction Schedule Name
> On , Marco Aldegheri <<mailto:m.aldegheri@xxxxxxxxx>m.aldegheri@xxxxxxxxx> wrote:
> Ok, I tried this solution but I wish to explain better my system to have a confirmation about my implementation...
> Â I have a residential building with 14 flats.
>
> The only things I know about my (real) air system are:
> -the articulation of the loop: Outdoor air->External fan->Heat exchanger->Electric heating coil->Zone->Heat exchanger->Outdoor air
> -the air temperature of the air flow entering into a zone, which is 18°C if Tair outdoor<=18°C, T in air =Tair outdoor if Tair outdoor is >18°C,
> -If the outdoor air is <18°C an electric coil will increase it up to 18°C
> -the maximum air flow rate of the fans which is 0.0238 m3/s,
> -the ON period of the system (schedule),
>
> Each flat has an independent air loop. (in this case P0A1 is a flat)
>
>
>
> The elements are like these, for fans: I underline the schedule and the flow rate
>
> !-Â Â ===========Â ALL OBJECTS IN CLASS: FAN:CONSTANTVOLUME ===========
>
> Fan:ConstantVolume,
>    Air Loop P0A1 AHU Extract Fan, !- Name
>    10010,                  !- Availability Schedule Name
>    0.70,                   !- Fan Total Efficiency
>    600.00,                 !- Pressure Rise {Pa}
>    0.0236,                 !- Maximum Flow Rate {m3/s}
>    0.90,                   !- Motor Efficiency
>    1.00,                   !- Motor In Airstream Fraction
>    Air Loop P0A1 Supply Side Inlet, !- Air Inlet Node Name
>    Air Loop P0A1 AHU Extract Fan Air Outlet Node, !- Air Outlet Node Name
> Â Â Â General;Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- End-Use Subcategory
>
>
>
>
>
> For the heating electric coils:
>
> Coil:Heating:Electric,
>    P0:P0%A1Zn5i Singolo Canale CAV con ReRiscaldamento Batteria di Riscaldamento, !- Name
>    10010,                  !- Availability Schedule Name
>    1.00,                   !- Efficiency
>    autosize,               !- Nominal Capacity {W}
>    Air Loop P0A1 Zone Splitter Outlet Node 3, !- Air Inlet Node Name
>    P0:P0%A1Zn5i Singolo Canale CAV con ReRiscaldamento Supply Inlet, !- Air Outlet Node Name
> Â Â Â P0:P0%A1Zn5i Singolo Canale CAV con ReRiscaldamento Supply Inlet;Â !- Temperature Setpoint Node Name
>
>
>
>
>
> In the Sizing:System I set for each loops this...
>
> Sizing:System,
>    Air Loop P0A1,          !- AirLoop Name
>    VentilationRequirement, !- Type of Load to Size On
>    autosize,               !- Design Outdoor Air Flow Rate {m3/s}
>    1.0,                    !- Minimum System Air Flow Ratio
>    5.00,                   !- Preheat Design Temperature {C}
>    0.00800,                !- Preheat Design Humidity Ratio {kgWater/kgDryAir}
>    11.00,                  !- Precool Design Temperature {C}
>    0.00800,                !- Precool Design Humidity Ratio {kgWater/kgDryAir}
>    12.00,                  !- Central Cooling Design Supply Air Temperature {C}
>    20,                     !- Central Heating Design Supply Air Temperature {C} ****
>    Noncoincident,          !- Sizing Option
>    Yes,                    !- 100% Outdoor Air in Cooling
>    Yes,                    !- 100% Outdoor Air in Heating
>    0.00800,                !- Central Cooling Design Supply Air Humidity Ratio {kgWater/kgDryAir}
>    0.00800,                !- Central Heating Design Supply Air Humidity Ratio {kgWater/kgDryAir}
>    Designday,              !- Cooling Design Air Flow Method
>    0.0000,                 !- Cooling Design Air Flow Rate {m3/s}
>    Designday,              !- Heating Design Air Flow Method
>    0.0000,                 !- Heating Design Air Flow Rate {m3/s}
>    ZoneSum,                !- System Outdoor Air Method
> Â Â Â 1.0000;Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Zone Maximum Outdoor Air Fraction {dimensionless}
>
> ****I tried using  18,                     !- Central Heating Design Supply Air Temperature {C}
> but I had the same severe error. So I tried to change the value (the original value of this field was 50°C because this idf was generated by DesignBuilder... I don't know why it has been set this to 50°C and especial if my changing is correct)
>
>
>
>
> for Sizing:Zone I set,
>
> Sizing:Zone,
>    P0:P0%A1Zn5i,           !- Zone or ZoneList Name
>    SupplyAirTemperature,   !- Zone Cooling Design Supply Air Temperature Input Method
>    14.00,                  !- Zone Cooling Design Supply Air Temperature {C}
>    5.00,                   !- Zone Cooling Design Supply Air Temperature Difference {deltaC}
>    SupplyAirTemperature,   !- Zone Heating Design Supply Air Temperature Input Method
>    18,                     !- Zone Heating Design Supply Air Temperature {C}
>    15.00,                  !- Zone Heating Design Supply Air Temperature Difference {deltaC}
>    0.0090,                 !- Zone Cooling Design Supply Air Humidity Ratio {kgWater/kgDryAir}
>    0.0040,                 !- Zone Heating Design Supply Air Humidity Ratio {kgWater/kgDryAir}
>    P0:P0%A1Zn5i Design Specification Outdoor Air Object, !- Design Specification Outdoor Air Object Name
>    1.25,                   !- Zone Heating Sizing Factor
>    1.15,                   !- Zone Cooling Sizing Factor
>    DesignDay,              !- Cooling Design Air Flow Method
>    0.000000,               !- Cooling Design Air Flow Rate {m3/s}
>    0.000760,               !- Cooling Minimum Air Flow per Zone Floor Area {m3/s-m2}
>    0.000000,               !- Cooling Minimum Air Flow {m3/s}
>    0.00,                   !- Cooling Minimum Air Flow Fraction
>    DesignDay,              !- Heating Design Air Flow Method
>    0.000000,               !- Heating Design Air Flow Rate {m3/s}
>    0.002030,               !- Heating Maximum Air Flow per Zone Floor Area {m3/s-m2}
>    0.141580,               !- Heating Maximum Air Flow {m3/s}
>    0.30,                   !- Heating Maximum Air Flow Fraction
> Â Â Â P0:P0%A1Zn5i Design Specification Zone Air Distribution Object;Â !- Design Specification Zone Air Distribution Object Name
>
> On Thursday, May 1, 2014 10:41 AM, "<mailto:jeannieboef@xxxxxxxxx>jeannieboef@xxxxxxxxx" <<mailto:jeannieboef@xxxxxxxxx>jeannieboef@xxxxxxxxx> wrote:
> Â
No. Look in the ioref at the sizing:plant object. You can (now) size the equipment as one does in Europe, by ventilation rate, so that the AHU does not try and meet the zone loads, just brings the air in at the specified temp.
>
> Mit freundlichen Grü�en- Sent from my iPhone (excuse the brevity)
> i. A.
Jean Marais
b.i.g. bechtold
Tel. Â <tel:%2B49%2030%206706662-23>+49 30 6706662-23
> On 01.05.2014, at 09:39, Marco Aldegheri <<mailto:m.aldegheri@xxxxxxxxx>m.aldegheri@xxxxxxxxx> wrote:
>
>> Â
Do you mean the Design outdoor Air Flow rate? Actually it was on: autosize. I set the maximum design air flow for the fans with a project value but maybe the field you are speaking about should be set to the same value.
I have changed it and I'm trying another run.
In an hour I'll have the results.
>> On , Marco Aldegheri <<mailto:m.aldegheri@xxxxxxxxx>m.aldegheri@xxxxxxxxx> wrote:
>> On Wednesday, April 30, 2014 11:35 PM, "<mailto:jeannieboef@xxxxxxxxx>jeannieboef@xxxxxxxxx" <<mailto:jeannieboef@xxxxxxxxx>jeannieboef@xxxxxxxxx> wrote:
>> Â
Without looking at the attatchments, I suspect that you have not set the (I think third field) sizing:system object to  size by ventilation rate instead of sensible load.
>>
>> Mit freundlichen Grü�en- Sent from my iPhone (excuse the brevity)
>> i. A.
Jean Marais
b.i.g. bechtold
Tel. Â <tel:%2B49%2030%206706662-23>+49 30 6706662-23
>> On 30.04.2014, at 23:02, <<mailto:m.aldegheri@xxxxxxxxx><mailto:m.aldegheri@xxxxxxxxx>m.aldegheri@xxxxxxxxx> wrote:
>>
>>> Â
Dear all,
>>>
>>> I'm having some trouble with a simulation.
>>>
>>> In my idf, the HVAC system is composed of 2 different entities: a radiant low temperature heating system and a mechanical ventilation system which should provide only a defined air change in my zones. Each of them works only during winter time.
>>>
>>> I upload the .svg to show how the system is realized. In particolar, my mec vent system is not properly a heating system, it provides an only airflow but with a control on the temperature. Just before the entrance of the air flux in a zone, there is a heating coil which should increase the incoming air temperature until 18°C, if the outside air temperature is less than 18°C. If the outside air temperature is >18°C the air flux is not heated by this coil. I should have set this using SetpointManager:OutdoorAirReset,
>>>
>>> SetpointManager:OutdoorAirReset,
>>>    Air Loop Setpoint Manager, !- Name
>>>    Temperature,            !- Control Variable
>>>    18.00,                  !- Setpoint at Outdoor Low Temperature {C}
>>>    -20.00,                 !- Outdoor Low Temperature {C}
>>>    18.00,                  !- Setpoint at Outdoor High Temperature {C}
>>>    18.00,                  !- Outdoor High Temperature {C}
>>> Â Â Â Air Loop Setpoint Manager Node List;Â !- Setpoint Node or NodeList Namet;
>>>
>>> I would like to ask you if do you mind how to fix this error. I have many severe errors like this one, one error for each thermal zone.
>>>
>>>   ** Severe ** UpdateZoneSizing: Heating supply air temperature (calculated) within 2C of zone temperature
>>> Â Â **Â Â ~~~Â Â ** ...check zone thermostat set point and design supply air temperatures
>>> Â Â **Â Â ~~~Â Â ** ...zone name = P0:P0%A1ZN4B
>>>   **  ~~~  ** ...design heating load        = 0.00 W
>>>   **  ~~~  ** ...thermostat set piont temp  = 0.000 C
>>>   **  ~~~  ** ...zone temperature           = 17.898 C
>>>   **  ~~~  ** ...supply air temperature     = 18.000 C
>>>   **  ~~~  ** ...temperature difference     = 0.10230 C
>>> Â Â **Â Â ~~~Â Â ** ...calculated volume flow rate = 8253.19807 m3/s
>>>   **  ~~~  ** ...calculated mass flow rate  = 9723.31707 kg/s
>>>
>>> Maybe the problem is in the design supply air temperatures, which I set to 18°C but I don't understand exaclty what's wrong...
>>> !-Â Â ===========Â ALL OBJECTS IN CLASS: SIZING:ZONE ===========
>>>
>>> Sizing:Zone,
>>>    P0:P0%A1Zn5i,           !- Zone or ZoneList Name
>>>    SupplyAirTemperature,   !- Zone Cooling Design Supply Air Temperature Input Method
>>>    14.00,                  !- Zone Cooling Design Supply Air Temperature {C}
>>>    5.00,                   !- Zone Cooling Design Supply Air Temperature Difference {deltaC}
>>>    SupplyAirTemperature,   !- Zone Heating Design Supply Air Temperature Input Method
>>>    18,                     !- Zone Heating Design Supply Air Temperature {C}
>>>    15.00,                  !- Zone Heating Design Supply Air Temperature Difference {deltaC}
>>>    0.0090,                 !- Zone Cooling Design Supply Air Humidity Ratio {kgWater/kgDryAir}
>>>    0.0040,                 !- Zone Heating Design Supply Air Humidity Ratio {kgWater/kgDryAir}
>>>    P0:P0%A1Zn5i Design Specification Outdoor Air Object, !- Design Specification Outdoor Air Object Name
>>>    1.25,                   !- Zone Heating Sizing Factor
>>>    1.15,                   !- Zone Cooling Sizing Factor
>>>    DesignDay,              !- Cooling Design Air Flow Method
>>>    0.000000,               !- Cooling Design Air Flow Rate {m3/s}
>>>    0.000760,               !- Cooling Minimum Air Flow per Zone Floor Area {m3/s-m2}
>>>    0.000000,               !- Cooling Minimum Air Flow {m3/s}
>>>    0.00,                   !- Cooling Minimum Air Flow Fraction
>>>    DesignDay,              !- Heating Design Air Flow Method
>>>    0.000000,               !- Heating Design Air Flow Rate {m3/s}
>>>    0.002030,               !- Heating Maximum Air Flow per Zone Floor Area {m3/s-m2}
>>>    0.141580,               !- Heating Maximum Air Flow {m3/s}
>>>    0.30,                   !- Heating Maximum Air Flow Fraction
>>> Â Â Â P0:P0%A1Zn5i Design Specification Zone Air Distribution Object;Â !- Design Specification Zone Air Distribution Object Name
>>>
>>> Thank you all,
Marco
>>>
>>> <https://groups.yahoo.com/neo/groups/EnergyPlus_Support/attachments/1413256645;_ylc=X3oDMTJxODk3bzFrBF9TAzk3MzU5NzE0BGdycElkAzMzODc0ODgEZ3Jwc3BJZAMxNzA1MDA3Mzg5BHNlYwNhdHRhY2htZW50BHNsawN2aWV3T25XZWIEc3RpbWUDMTM5ODg5MTc2MA-->>>> View attachments on the web
<https://groups.yahoo.com/neo/groups/EnergyPlus_Support/conversations/messages/31837;_ylc=X3oDMTJxOW9zNm42BF9TAzk3MzU5NzE0BGdycElkAzMzODc0ODgEZ3Jwc3BJZAMxNzA1MDA3Mzg5BG1zZ0lkAzMxODM3BHNlYwNmdHIEc2xrA3JwbHkEc3RpbWUDMTM5ODg5MTc2MA--?act=reply&messageNum=31837>Reply via web post ? <mailto:m.aldegheri@xxxxxxxxx?subject=Re%3A%20Problem%20with%20UpdateZoneSizing%3A%20Heating%20supply%20air%20temperature> Reply to sender ? <mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx?subject=Re%3A%20Problem%20with%20UpdateZoneSizing%3A%20Heating%20supply%20air%20temperature> Reply to group ? <https://groups.yahoo.com/neo/groups/EnergyPlus_Support/conversations/newtopic;_ylc=X3oDMTJlM3FtNXF0BF9TAzk3MzU5NzE0BGdycElkAzMzODc0ODgEZ3Jwc3BJZAMxNzA1MDA3Mzg5BHNlYwNmdHIEc2xrA250cGMEc3RpbWUDMTM5ODg5MTc2MA-->Start a New Topic ? <https://groups.yahoo.com/neo/groups/EnergyPlus_Support/conversations/topics/31837;_ylc=X3oDMTM2a3FnaHY5BF9TAzk3MzU5NzE0BGdycElkAzMzODc0ODgEZ3Jwc3BJZAMxNzA1MDA3Mzg5BG1zZ0lkAzMxODM3BHNlYwNmdHIEc2xrA3Z0cGMEc3RpbWUDMTM5ODg5MTc2MAR0cGNJZAMzMTgzNw-->Messages in this topic (1)
<https://groups.yahoo.com/neo;_ylc=X3oDMTExc2JuanI3BF9TAzk3MzU5NzE0BGNmMTADQ1AEc2VjA21lZ2FwaG9uZQ-->
Now you can search Photos & Files in your Group !
You can now search not only your archive of conversations, but also photos and files stored in your Yahoo Group. Give it a try!
<http://yahoogroups.tumblr.com/post/79361353100/photo-and-files-search-launched>
>>> <MRD xlam 30-04 recup dati dimensionamento modif.svg>
>>> <MRD xlam 30-04 recup dati dimensionamento modif.rar>
>>
>>
>>
>
>
>
> Dear Jean, is this what you mean?
> Do I have to correct anything?
> At the moment I'm running a simulation with these parameters.
>
> Thanks for your time.
> Marco
>
>
>
>
>
__._,_.___
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=31850/stime=1399009488>
<https://groups.yahoo.com/neo/groups/EnergyPlus_Support/info;_ylc=X3oDMTJlNDQ1dWhqBF9TAzk3MzU5NzE0BGdycElkAzMzODc0ODgEZ3Jwc3BJZAMxNzA1MDA3Mzg5BHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTM5OTAwOTQ4OA-->Visit Your Group
* <https://groups.yahoo.com/neo/groups/EnergyPlus_Support/members/all;_ylc=X3oDMTJmODZyczE3BF9TAzk3MzU5NzE0BGdycElkAzMzODc0ODgEZ3Jwc3BJZAMxNzA1MDA3Mzg5BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzEzOTkwMDk0ODg->New Members 9
<https://groups.yahoo.com/neo;_ylc=X3oDMTJkbG5wZjVyBF9TAzk3NDc2NTkwBGdycElkAzMzODc0ODgEZ3Jwc3BJZAMxNzA1MDA3Mzg5BHNlYwNmdHIEc2xrA2dmcARzdGltZQMxMzk5MDA5NDg4><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
__,_._,___