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AirSystem and ThrmlZn sizing parameters #225

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
Describe the translation issue or enhancement:
Reverse translator is not translating the sizing run parameters specified at 
AirSys and ThrmlZn

If issue occurs during translation, describe what steps reproduce the
problem:
See attached spreadsheet and models that illustrate the SDD properties as they 
relate to E+ sizing fields, as well as what other values can be defaulted.  
Example IDF also attached.

What version of OpenStudio are you using? On what operating system?
r11992

Please provide any additional information below.

Original issue reported on code.google.com by da...@360-analytics.com on 18 May 2013 at 6:12

Attachments:

GoogleCodeExporter commented 9 years ago 
As far as I can tell, components of this issue are still open (thermal zone 
airflow sizing method, sizing factors, etc).

Original comment by da...@360-analytics.com on 8 Aug 2013 at 5:57

GoogleCodeExporter commented 9 years ago 
Kyle, 
Do you still have these on your radar for adding the ThrmlZn sizing parameters 
to OS?

Original comment by da...@360-analytics.com on 25 Sep 2013 at 12:19

GoogleCodeExporter commented 9 years ago 
The SDD has been updated to include the revised zone sizing properties for 
translation to OS. Attached is an example SDD XML file. 

Here are the relevant SDD 'Sim' Properties:
ClgDsgnSupAirTemp -> Field: Zone Cooling Design Supply Air Temperature
HtgDsgnSupAirTemp -> Field: Zone Heating Design Supply Air Temperature
HtgDsgnSizingFac -> Field: Zone Heating Sizing Factor
ClgDsgnSizingFac -> Field: Zone Cooling Sizing Factor
HtgDsgnMaxFlowFrac -> Field: Heating Maximum Air Flow Fraction

The following are not defined in the SDD, but to be assumed to be:

Field: Cooling Design Air Flow Method = DesignDay
Field: Heating Design Air Flow Method = if HtgDsgnMaxFlowFrac > 0 then 
"DesignDayWithLimit" else "DesignDay"

As discussed on phone, SDD currently does not include a property for Zone 
Cooling/Heating Design Supply Air Humidity Ratio.  Please default these for 
now, will test to see if they result in simulation errors.

Other E+ Sizing:Zone properties not described above should be 0 or blank with 
the exception of:
!- Design Specification Outdoor Air Object Name
!- Design Specification Zone Air Distribution Object Name

Original comment by da...@360-analytics.com on 15 Oct 2013 at 4:19

Attachments:

GoogleCodeExporter commented 9 years ago 
David, should these be defaulted to specific values?  I don't see these 
properties in the current SDD files in my test suite, outside of the example 
file attached to this ticket.  I suspect changes might not have made it into 
updated SDD instances yet.

Original comment by kbe...@gmail.com on 16 Oct 2013 at 9:22

GoogleCodeExporter commented 9 years ago 
The properties will be defaulted by CBECC, but you can add your own defaults as 
a back up.  The other SDD instances have not been updated yet.  I will update 
the others once I hear that there are no other questions/changes made.  So in 
the near term, please test with the model attached to ticket and then let me 
know when complete; I'll update others.

Original comment by da...@360-analytics.com on 16 Oct 2013 at 9:30

GoogleCodeExporter commented 9 years ago 
Reviewed updates and find that the following E+ Sizing:Zone properties are set 
regardless of SDD inputs:

  0.000762,                               !- Cooling Minimum Air Flow per Zone Floor Area {m3/s-m2} 

  0.002032,                               !- Heating Maximum Air Flow per Zone Floor Area {m3/s-m2}
  0.1415762,                              !- Heating Maximum Air Flow {m3/s}

Where do these defaults values come from? I may have provided incorrect 
guidance in comment #5, as I expected default values only to be input for the 
fields listed above, not other Sizing:Zone fields.

As I understand it, these fields are only recognized if the Flow/Zone or 
DesignDayWithLimit methods are used; please confirm.  If they are not 
applicable, is it possible to exclude from the IDF file?  I believe this would 
eliminate some confusion in reviewing the output files.

In the case of that ThrmlZn:HtgDsgnMaxFlowFrac is GT 0, the DesignDayWithLimit 
method IS used, and therefore, these default properties could interfere with 
the intended HtgDsgnMaxFlowFrac limit specified in the SDD.

Otherwise, the translator updates described in this issue have been verified 
complete. Will wait to get response on final issues described above.

Original comment by da...@360-analytics.com on 21 Oct 2013 at 6:48

GoogleCodeExporter commented 9 years ago 
Your guidance was fine.  The defaults are coming from OpenStudio / EnergyPlus 
IDD.  But we are going to need to figure out something for one of these or I 
don't think our VAV terminals will size.

  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

See the text from the IO Doc

"The minimum zone cooling volumetric flow rate in m3/s. This field is used when 
Cooling Design Air Flow Method is specified as DesignDayWithLimit. In this case 
it sets a lower bound on the zone design cooling air flow rate. In all cases 
the maximum flow derived from Cooling Minimum Air Flow per Zone Floor Area, 
Cooling Minimum Air Flow, and Cooling Minimum Air Flow Fraction is used to set 
a minimum supply air flow rate for the zone for VAV systems. The default is 
zero. The applicable sizing factor is not applied to this value."

Perhaps you are interpreting this differently than I am, and your 
interpretation might be right.  I read this such that if we don't specify any 
minimum our terminals wont have a floor.  I will do some testing...

Original comment by kbe...@gmail.com on 21 Oct 2013 at 9:46

GoogleCodeExporter commented 9 years ago 
I addressed the default concerns in the following commit.  From testing as long 
as we use DesignDay or DesignDayWithLimit we will have terminal capacity.  For 
heating maximum air flow, we use DesignDay unless there is a 
HeatingMaximumAirFlowFraction in which case we use DesignDayWithLimit.  Any air 
flow limit not specified is now set to zero, which does not cause any issue 
when we use the DesignDay method.  I think these values are more clear because 
they remove default values from unknown sources.

commit db971b323b440fcd47dd2ee91386c041b39ff594
Author: Kyle Benne <kyle.benne@nrel.gov>
Date:   Tue Oct 22 09:47:36 2013 -0500

    SDD: Adjust zone sizing parameters

    This removes default values for zone sizing heating and cooling air flow
    rates.  Only values from the SDD xml file will be used.  The design air
    flow method will be set to DesignDay unless the SDD specifies a heating
    or cooling air flow, in which case the method is DesignDayWithLimit.

Original comment by kbe...@gmail.com on 22 Oct 2013 at 3:00

GoogleCodeExporter commented 9 years ago 
Thanks for reviewing/testing.  Will close this out once we test via CBECC or a 
package.

Original comment by da...@360-analytics.com on 25 Oct 2013 at 6:00

GoogleCodeExporter commented 9 years ago 
Closing issue, translator updates complete and will be reviewed under Issue 306

Original comment by da...@360-analytics.com on 8 Nov 2013 at 3:21