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2019-05-15 10:05:09 -0500 marked best answer Does DaylightingDevice:Shelf causing unenclosed zone output inaccurate results?

Simulating DaylightingDeviceShelf.idf from the Energyplus 9.0 Examples Files, with an Output:Diagnostics,DisplayExtrawarnings object added, creates a warning

* Warning * CalculateZoneVolume: The Zone="DAYLIT ZONE" is not fully enclosed. To be fully enclosed, each edge of a surface must also be an edge on one other surface.

The Warning continues saying the zone volume calculation is done by

* ~~~ * The zone volume was calculated using the floor area times ceiling height method where the floor and ceiling are the same except for the z-coordinates.

Granted, the proper way to specify a light shelf in energyplus is unusual, but it shouldn't create this warning.


What I really care about though is if this will or will not output accurate results. Is there any way to find out?

Energyplus github issue

2019-05-15 10:05:05 -0500 commented answer Does DaylightingDevice:Shelf causing unenclosed zone output inaccurate results?

@JasonGlazer Good enough! I'll accept my answer.

2019-05-14 18:23:36 -0500 answered a question Measure of light and temperature specifically of a solar panel

There are a few models you can use for a PV panel in Energylus. PhotovoltaicPerformance:Simple PhotovoltaicPerformance:E

2019-05-11 09:55:06 -0500 marked best answer How to delete an object from the idf file in an energyplus measure?

I know this is very easy in an openstudio measure, but how do I delete an object from the idf file using an energyplus measure?

Also, is there any documentation for writing energyplus measures similar to the openstudio documentation?

https://openstudio-sdk-documentation....

2019-05-09 20:27:15 -0500 edited question Does DaylightingDevice:Shelf causing unenclosed zone output inaccurate results?

Does DaylightingDevice:Shelf causing unenclosed zone output inaccurate results? Simulating DaylightingDeviceShelf.idf fr

2019-05-09 20:25:01 -0500 edited answer Does DaylightingDevice:Shelf causing unenclosed zone output inaccurate results?

I may have a workaround for this, but would like an expert opinion. I changed the single inner shading surface into two

2019-05-09 20:23:20 -0500 commented answer Does DaylightingDevice:Shelf causing unenclosed zone output inaccurate results?

@JasonGlazer Do you know if the inner light shelf will reflect light into the space correctly, or at least pretty well?

2019-05-09 20:20:51 -0500 answered a question Does DaylightingDevice:Shelf causing unenclosed zone output inaccurate results?

I may have a workaround for this, but would like an expert opinion. I changed the single inner shading surface into two

2019-05-09 19:35:03 -0500 commented answer OpenStudio geometry tab renders EnergyPlus example file surfaces as white

@David Goldwasser @macumber I found it.

2019-05-09 19:34:25 -0500 answered a question OpenStudio geometry tab renders EnergyPlus example file surfaces as white

I figured it out. There is a case sensitive problem. The surfaces that are white were "WALL" and when I changed them to

2019-05-09 19:05:42 -0500 commented question OpenStudio geometry tab doesn't render wall with two windows

@David Goldwasser Are you able to reproduce this on your computer?

2019-05-09 19:05:09 -0500 marked best answer OpenStudio geometry tab renders EnergyPlus example file surfaces as white

The file is AirflowNetwork_Simple_House.idf which is an EnergyPlus 9.0.1 example file. Importing the idf into openstudio 2.8.0 and clicking the geometry tab displays some of the walls colored white instead of the usual tan. My OS is Windows 10.

image description

There is a similar post here, but that post is from 2014 and has to do with modifying the geometry using sketchup, which I have not done.

Post Script
The white walls also stay opaque when turning off displaying the walls.

image description

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2019-05-09 19:04:06 -0500 asked a question OpenStudio geometry tab doesn't render wall with two windows

OpenStudio geometry tab doesn't render wall with two windows I found a problem with geometry tab for the DaylightingDevi

2019-05-09 07:05:02 -0500 marked best answer Changing the idd file for energyplus measures

I tried modifying the Energy+.idd files in two locations to customize the field values of an object created in an energyplus measure. The two idd files I modified are
C:\openstudio-2.6.0\EnergyPlus\Energy+.idd
and
C:\EnergyPlusV8-9-0\Energy+.idd

As an example, I choose to modify the "Outdoor Air Equipment List Name" of the AirLoopHVAC:OutdoorAirSystem object.

AirLoopHVAC:OutdoorAirSystem,
  DOAS OA System,                         !- Name
  DOAS OA System Controllers,             !- Controller List Name
  DOAS OA System Equipment,               !- Outdoor Air Equipment List Name
  DOAS Availability Managers;             !- Availability Manager List Name

I attempted to write this object to the idf file using

  string_object = "
AirLoopHVAC:OutdoorAirSystem,
  DOAS OA System,                         !- Name
  DOAS OA System Controllers,             !- Controller List Name
  ,                                       !- Outdoor Air Equipment List Name
  DOAS Availability Managers;             !- Availability Manager List Name
      "
  idfObject = OpenStudio::IdfObject::load(string_object)
  object = idfObject.get
  wsObject = workspace.addObject(object)

but the "DOAS OA System Equipment" object hadn't been defined yet, meaning assigning "DOAS OA System Equipment" to the "Outdoor Air Equipment List Name" would be invalid since the referenced object doesn't exist yet. So the idf file contained this instead

AirLoopHVAC:OutdoorAirSystem,
  DOAS OA System,                         !- Name
  DOAS OA System Controllers,             !- Controller List Name
  ,                                       !- Outdoor Air Equipment List Name
  DOAS Availability Managers;             !- Availability Manager List Name

So I modified the AirLoopHVAC:OutdoorAirSystem portion of the Energy+.idd file in both locations.

AirLoopHVAC:OutdoorAirSystem,
       \memo Outdoor air subsystem for an AirLoopHVAC. Includes an outdoor air mixing box and
       \memo optional outdoor air conditioning equipment such as heat recovery, preheat, and precool
       \memo coils. From the perspective of the primary air loop the outdoor air system is treated
       \memo as a single component.
       \min-fields 3
   A1, \field Name
       \required-field
       \type alpha
       \reference-class-name validBranchEquipmentTypes
       \reference validBranchEquipmentNames
   A2, \field Controller List Name
       \note Enter the name of an AirLoopHVAC:ControllerList object.
       \required-field
       \type object-list
       \object-list ControllerLists
   A3, \field Outdoor Air Equipment List Name
       \note Enter the name of an AirLoopHVAC:OutdoorAirSystem:EquipmentList object.
       \required-field
       \type object-list
       \object-list AirLoopOAEquipmentLists
   A4; \field Availability Manager List Name
       \note Enter the name of an AvailabilityManagerAssignmentList object.
       \type object-list
       \object-list SystemAvailabilityManagerLists

changing the A3 field to

   A3, \field Outdoor Air Equipment List Name
       \note Enter the name of an AirLoopHVAC:OutdoorAirSystem:EquipmentList object.
       \required-field
       \type alpha

The change showed up in the IDFEditor as the required orange color when the field is blank was gone, but the measure still failed to put "DOAS OA System Equipment" in the A3 field since the "DOAS OA System Equipment" object hadn't been defined yet.

So if the idd file for openstudio and the different idd file energyplus don't control the behavior for energyplus measures modifying objects, what does?

2019-05-09 07:05:01 -0500 received badge  Self-Learner (source)
2019-05-08 11:15:33 -0500 asked a question What is the Connector List Name field in the AirLoopHVAC object for?

What is the Connector List Name field in the AirLoopHVAC object for? The Connector List Name field of the AirLoopHVAC ob

2019-05-08 10:26:17 -0500 asked a question How is solar thermal panel heating calculated?

How is solar thermal panel heating calculated? I started looking more closely at the SolarCollectorFlatPlateWater.idf ex

2019-05-08 10:24:25 -0500 edited question Solar Collector outputs -100C water in San Diego

Solar Collector outputs -100C water in San Diego I am modeling a SolarCollector:FlatPlate:Water and the temperatures don

2019-05-07 20:03:20 -0500 edited question Solar Collector outputs -100C water in San Diego

Solar Collector outputs -100C water in San Diego I am modeling a SolarCollector:FlatPlate:Water and the temperatures don

2019-05-07 18:19:06 -0500 asked a question Solar Collector outputs -100C water in San Diego

Solar Collector outputs -100C water in San Diego I am modeling a SolarCollector:FlatPlate:Water and the temperatures don

2019-05-06 12:39:00 -0500 commented answer OpenStudio geometry tab renders EnergyPlus example file surfaces as white

@David Goldwasser I upgraded from openstudio 2.7.0 to 2.8.0. I refetched the AirflowNetwork_Simple_House.idf energyplus

2019-05-06 12:36:14 -0500 edited question OpenStudio geometry tab renders EnergyPlus example file surfaces as white

OpenStudio geometry tab renders EnergyPlus example file surfaces as white The file is AirflowNetwork_Simple_House.idf wh

2019-04-26 17:18:53 -0500 marked best answer More Columns in ExampleFiles-ObjectsLink.html

I'd really like to be able to view more than the first three example idf file names where an object is used in the ExampleFiles-ObjectsLink.html file. Is there an easy way to do that?

2019-04-26 17:07:17 -0500 asked a question More Columns in ExampleFiles-ObjectsLink.html

More Columns in ExampleFiles-ObjectsLink.html I'd really like to be able to view more than the first three example idf f

2019-04-22 17:00:47 -0500 marked best answer How to plot times SimHVAC exceeded max iterations?

I have a VAV system which is creating a bunch of warnings about convergence, but other unmethours posts indicate that these warnings may not be a problem. For instance, if the warning only occurs once a day when the HVAC system first turns on, then I think I can safely ignore the warnings. However, I don't know of an easy way to plot the times when all those warnings occur. Plots of Output:Variables and Output:Meters are extremely useful for diagnosing problems, and practical because everything is outputted to a CSV file, which is why I'm hoping to do the same with these SimHVAC warnings.

How do I output the times these SimHVAC warnings occur, and in general when warnings, severe errors, and fatal errors occur in a practical format like a CSV file?

Post Script
I tried out the Output:Variables @rraustad recommended and the SimHVAC error is happening pretty much every time step in the summer. So not just when the system turns on.

I don't mean to be the post that goes, "Something's wrong. Help!!!", but do you see anything obvious place to look in the idf file based on the error output. These error seems to repeat over and over again. If not, then I'll start going through all the objects field by field and hope I spot my incorrect value. (Errors included as an image so I'd get word wrap. Open image in a new tab to enlarge to readable sized text.)

image description

2019-04-22 16:59:37 -0500 commented answer How to plot times SimHVAC exceeded max iterations?

@rraustad The output variables showed the nonconvergence is happening way too often to ignore. Does anything jump out at

2019-04-22 16:58:20 -0500 edited question How to plot times SimHVAC exceeded max iterations?

How to plot times SimHVAC exceeded max iterations? I have a VAV system which is creating a bunch of warnings about conve

2019-04-22 16:57:50 -0500 edited question How to plot times SimHVAC exceeded max iterations?

How to plot times SimHVAC exceeded max iterations? I have a VAV system which is creating a bunch of warnings about conve

2019-04-20 17:56:22 -0500 asked a question Conditionally turn on solar thermal collectors pump based on storage tank temperature

Conditionally turn on solar thermal collectors pump based on storage tank temperature I was using the SolarCollectorFlat

2019-04-20 14:07:05 -0500 asked a question How to plot times SimHVAC exceeded max iterations?

How to plot times SimHVAC exceeded max iterations? I have a VAV system which is creating a bunch of warnings about conve

2019-04-19 11:03:18 -0500 commented answer When do you actually need a bypass pipe?

@MJWitte Okay. That answers my question. In general, plant components like chillers, boilers, hot water heaters, etc. al

2019-04-19 10:24:00 -0500 commented answer Chiller loop getting to 322C in first timestep of design day and causing Severe error

@rraustad I tried fiddling around a bit, but increasing the PlantLoop upper temperature limit works pretty well. I don't

2019-04-19 09:37:59 -0500 marked best answer Where user specified value disagrees with autosizing?

I have a sizing disagreement in my idf file, but I'm having trouble finding where I inputted the conflicting fields. Any ideas on where I should look? And here is a google drive link to the files.

Here is the relevant part of the ERR file:

   ************* SizeWaterCoil: Potential issue with equipment sizing for Coil:Cooling:Water LGSTORE1 ZN COOLING COIL
   **   ~~~   ** User-Specified Design Air Flow Rate [m3/s] = 0.79234
   **   ~~~   ** differs from Design Size Design Air Flow Rate [m3/s] = 0.87231
   **   ~~~   ** This may, or may not, indicate mismatched component sizes.
   **   ~~~   ** Verify that the value entered is intended and is consistent with other components.

Here is the relevant part of the EIO file:

 Component Sizing Information, Coil:Cooling:Water, LGSTORE1 ZN COOLING COIL, Design Size Design Air Flow Rate [m3/s], 0.87231
 Component Sizing Information, Coil:Cooling:Water, LGSTORE1 ZN COOLING COIL, User-Specified Design Air Flow Rate [m3/s], 0.79234

But the strange thing is I think those fields are autosized.

image description

Not sure if these are important, but those conflicting flow rates appear elsewhere in the EIO file.

 Zone Sizing Information, LGSTORE1 ZN, Heating, 16855.60896, 20226.73075, 0.72693, 0.87231, CLIMATE ZONE 12 ANN HTG 99.6% CONDNS DB, 12/21 13:00:00, -0.40000, 3.65329E-003, 348.38640, 30.00000, 0.41148, 0.00000

 Component Sizing Information, ZoneHVAC:FourPipeFanCoil, LGSTORE1 ZN FAN COIL, Design Size Maximum Supply Air Flow Rate [m3/s], 0.87231

 Component Sizing Information, Fan:OnOff, LGSTORE1 ZN SUPPLY FAN, Design Size Maximum Flow Rate [m3/s], 0.87231



 Zone Sizing Information, LGSTORE1 ZN, Cooling, 8994.03839, 10792.84607, 0.66028, 0.79234, CLIMATE ZONE 12 ANN CLG .4% CONDNS DB=>MWB, 7/21 15:00:00, 37.90000, 9.07726E-003, 348.38640, 30.00000, 0.41148, 0.00000

However, I think those fields are also autosized.

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2019-04-18 11:58:30 -0500 commented answer Chiller loop getting to 322C in first timestep of design day and causing Severe error

@rraustad I did that and the maximum temp of both the inlet and outlet of the pump was 24.60275C in CSV columns with the

2019-04-18 11:12:41 -0500 edited question Chiller loop getting to 322C in first timestep of design day and causing Severe error

Chiller loop getting to 322C in first timestep of design day and causing Severe error I'm having some difficulty running

2019-04-18 10:49:18 -0500 edited question Chiller loop getting to 322C in first timestep of design day and causing Severe error

Chiller loop getting to 322C in design day and causing Severe error I'm having some difficulty running a simulation. The

2019-04-18 10:45:25 -0500 edited question Chiller loop getting to 322C in first timestep of design day and causing Severe error

Chiller loop getting to 322C in design day and causing Severe error I'm having some difficulty running a simulation. The

2019-04-18 10:38:22 -0500 asked a question Chiller loop getting to 322C in first timestep of design day and causing Severe error

Chiller loop getting to 322C in design day and causing Severe error I'm having some difficulty running a simulation. The

2019-04-16 08:55:44 -0500 marked best answer Meeting Humidity Setpoint with Evaporative Media

I am setting up an HVAC system for a computer room. The person density in the computer room is 0 and the computers are always on generating much heat. There is no outdoor airflow due to fear of particles, and the cooling coil is always on, day and night, which condenses much of the water out of the air. Low humidity is bad for computers since static charge can build up and damage components, so water must be added to the air in the loop.

The best objects I've found is either of the EvaporativeCooler:Direct:CelDekPad or EvaporativeCooler:Direct:ResearchSpecial as opposed to the humidifies which heat the water. There is no reason to add heat to the airloop serving the computer equipment as the computer room never, ever needs heating.

However, I've run into a problem on how to control the direct evaporative coolers based on humidity. The ideal relative humidity for computer equipment is 45% - 55% and I don't see an easy way for the EvaporativeCooler:Direct to be turned on and off based on the humidity. What object would you recommend that are smart enough to control the fan, cooling coil, heating coil that is in in the airloop but is never used, and evaporative cooler to meet a temperature of 28C and relative humidity kept between 45% - 55%?

A possible alternative is to use a Humidifier:Steam:Electric object and specify the parameters in such a way that it evaporates water but generates zero heat. Then there are appropriate objects for controlling the equipment in the airloop based on temperature and humidity while not unnecessarily heating the computer equipment with a kluge parameter choice of the Humidifier:Steam:Electric object.

POST SCRIPT
Providing some data from the simulation, the humidity can get quite low if there is there is no humidifier present. These are the relative humidity values for the first day of January and the first day of July in a data center that does not possess a humidifier.

Date/Time   DATACENTER_MID_ZN_6:Zone Air Relative Humidity [%](Hourly)
 01/01  01:00:00    29.96093349
 01/01  02:00:00    29.95718355
 01/01  03:00:00    29.9684331
 01/01  04:00:00    29.96843366
 01/01  05:00:00    29.98718226
 01/01  06:00:00    29.97968237
 01/01  07:00:00    29.98718184
 01/01  08:00:00    30.01718079
 01/01  09:00:00    30.04717912
 01/01  10:00:00    30.07717769
 01/01  11:00:00    30.0884264
 01/01  12:00:00    30.06967808
 01/01  13:00:00    30.03967937
 01/01  14:00:00    30.0284301
 01/01  15:00:00    30.02842996
 01/01  16:00:00    30.02842954
 01/01  17:00:00    30.0096808
 01/01  18:00:00    29.99843139
 01/01  19:00:00    29.99843181
 01/01  20:00:00    29.99843125
 01/01  21:00:00    29.99843167
 01/01  22:00:00    30.01718055 ...
(more)