nrel/energyplus

EnergyPlus™ is a whole building energy simulation program that engineers, architects, and researchers use to model both energy consumption and water use in buildings.

EnergyPlus

This is the EnergyPlus Development Repository. EnergyPlus™ is a whole building energy simulation program that engineers, architects, and researchers use to model both energy consumption and water use in buildings.

Contact/Support

• The Department of Energy maintains a public website for EnergyPlus where you can find much more information about the program.
• For detailed developer information, consult the wiki.
• Many users (and developers) of EnergyPlus are active on Unmet Hours, so that's a great place to start if you have a question about EnergyPlus or building simulation.
• For more in-depth, developer-driven support, please utilize the EnergyPlus Helpdesk.

Testing

Every commit and every release of EnergyPlus undergoes rigorous testing. The testing consists of building EnergyPlus, of course, then there are unit tests, integration tests, API tests, and regression tests. Since 2014, most of the testing has been performed by our bots (Tik-Tok, Gort, and Marvin), using a fork of the Decent CI continuous integration system. We are now adapting our efforts to use the Github Actions system to handle more of our testing processes. In the meantime, while Decent CI is still handling the regression and bulkier testing, results from Decent CI are still available on the testing dashboard.

Releases

EnergyPlus is released twice annually, usually in March and September. It is recommended all use of EnergyPlus in production workflows use these formal, public releases. Iteration (pre-)releases may be created during a development cycle, however users should generally avoid these, as input syntax may change which won't be supported by the major release version transition tools, and could require manual intervention to remedy. If an interim release is intended for active use by users, such as a bug-fix-only or performance-only re-release, it will be clearly specified on the release notes and a public announcement will accompany this type of release. Our releases are now built by Github Actions.

Core Documentation

Program documentation is installed alongside the program, with the pdfs also available online. Big Ladder also produces html based documentation online.

API Documentation

An API has been developed to allow access to internal EnergyPlus functionality and open up the possibility for new workflow opportunities around EnergyPlus. A C API is developed to expose the C++ functions, then Python bindings are built on top of that to maximize the accessibility. Documentation is being built and posted on ReadTheDocs and that documentation will continue to be expanded over time as the API grows. The badges above here show the status, and link out to, the latest documentation (most recent commit to the develop branch) as well as the stable documentation (most recent release tag).

License & Contributing Development

EnergyPlus is available under a BSD-3-like license. For more information, check out the license file. The EnergyPlus team accepts contributions to EnergyPlus source, utilities, test files, documentation, and other materials distributed with the program. The current EnergyPlus contribution policy is now available on the EnergyPlus contribution policy page. If you are interested in contributing, please start there, but feel free to reach out to the team.

Building EnergyPlus

A detailed description of compiling EnergyPlus on multiple platforms is available on the wiki. Also, as we are adapting to using Github Actions, the recipes for building EnergyPlus can be found in our workflow files.

energyplus's Issues

No impact from changing hot water loop max temp to 0C. (CR #818)

Added on 1999-12-06 10:01 by @mjwitte

Description

MJW 99.12.03

Test 3251 is the StarTeam VAVSimple input file
with the Hot Water Loop Max Temperature set
from 100C back to 0C. There appears to be no
change in results. Test was done for 10 days
in Jan, Apr and Jul using dry/cool weather.
Used 12-1-99 version of exe.

Plant configuration shows heating coming from
purchased heating. No hot water pump is
specified. Must just be getting Btus (or Watts)
from purchased heating.

Is this why changing hot water loop max temp has no
effect? But shouldn't there be a loop temp associated with purchased heating anyway?

Input file: 065-VAVSimple-3251.idf
Weather: drycold.wea

Fix

This defect has been allowed to age, but it won't go away. Beta2
code still shows the same noneffect - lowering the hot water loop
maximum temperature in TermReheat.idf to 11 deg C has no effect.

The loop max Temperature input IS transferred to the loop nodes.
However the purchased hot water component never looks at the
incoming or outgoing node max temperature. All it does is add enough
heat to bring the water temperature up to the set point temperature.
In other words, it looks at the set point temperature, but not the max
temperature. It doesn't worry whether the max is less than the set point.

I suspect that the same holds true of some of the other simple "BTU"
component models. This is really a design issue not a defect. How
are we going to treat the max and min loop temperatures in our
component models? I'll mark this defect "as designed" and add it
to the list of things to discuss in Golden, May 2000.

Fred Buhl 3/31/2000

External Ref: 65
Last build tested: 00.03.29 Build 014, Beta 2

EP-Launch cannot be run without a weather file (CR #841)

Added on 2000-03-25 09:22 by @lklawrie

Description

EP-Launch appears to always access a weather file to run. Would prefer a check box that says to run without or be able to select "none"

Fix

Fixed in EP-Launch 0.21 (3/28/2000) added "No Weather File" option in pull down list.

External Ref: 95
Last build tested: 00.03.23 Build 010, Beta 2

People, Comfort parameters (CR #795)

Added on 1999-03-03 13:29 by @lklawrie

Description

As we add Thermal Comfort Parameters, the following parameters (from BLAST) are closely related to People and should be included on the People statement:

Metabolic Rate
Clothing Insulation
Work Efficiency

The Activity Level is based on the ASHRAE Heat Gain of people in
Conditioned Spaces which is further based on a heat gain at a specific
temperature.

Should we move totally to the more specific (from a user's point of
view), metabolic rate and clothing insulation? (Not sure about work
efficiency -- do we really need that? It would seem to be a modifier on
Metabolic rate) And can we derive the activity level (i.e. heat gain) from
the mets and clo values? (Based on the actual zone temperature.) Or will we need to have multiple PEOPLE:ActivityLevel and PEOPLE:MetRate or similar definitions.

Fix

2000.03.16 (RS): Thermal comfort has been added to EnergyPlus and the input parameters are slightly different from the original BLAST implementation. The first difference is that heat gain from occupants is entered as Watts rather than mets. This is due partially to the fact that the comfort and people statements have been consolidated into a single input statement. So, the request to include thermal comfort parameters in the people statement has been fulfilled.

In the PEOPLE statement, activity level and metabolic rate are essentially the same thing from the user's standpoint. I believe all of these concerns have been addressed with the recent changes to the PEOPLE statement and the addition of the Fanger thermal comfort model (with KSU and Pierce to follow).

External Ref: 18
Addressed in 00.03.23 Build 009, Beta 2
Last build tested: 99.02.25 Build of EnergyPlus

Detailed Interior Convection -- Windows (CR #838)

Added on 2000-04-06 07:28 by @lklawrie

Description

When the change was made to make sure there was no "divide by zero" for Window calculations and "detailed convection models", I think an explicit value is placed in a local variable in the module Window5Manager. This needs to change actual (reporting) variable for this as well. Though the actual condition may never occur during simulation (only during warmup), it is misleading to allow one value to be reported whereas, in actuality, another value is used for the calculation.

FW: will be completed in beta 4

Fix

The variable in question, hcin in Window5Manager, is never reported, so avoiding a zero value for hcin by setting it to a positive value when HConvIn is zero should cause no confusion.

External Ref: 110
Addressed in Beta 2 Release by F Winkelmann
Last build tested: 00.04.05 Beta 2 Release

Psychrometric errors in TermReheat example on MJW WinNT machine (CR #798)

Added on 1999-08-20 08:36 by @mjwitte

Description

Executed TermReheat.idf example file and got many psychrometric errors:

PSYWTR- 1639
SATUPT- 6

Using files from StarTeam:EnergyPlus:LicensedDevelopers:ExampleFiles
TermReheat.idf [Version #1, 29 May 1999 12:20:48

EnergyPlus from LicensedDevelopers:ProgramFiles
EnergyPlus.exe [Version #3, 26 Jul 1999 12:50:26

**NOTE the build number assigned here is wrong, but I had to choose something . . .

MJW 99/09/03
Tested this on two different machines:

A. WinNT 4.00.1381 on a Dell Dimension XPS R400, Pentium II 400 MHz, 64MB ram

B. Win95 on a Gateway 2000 P5-133, Pentium 133 MHz, 32MB ram

On the Win95 machine there were no psychrometric errors and the eso results matched the sample file.

On the WinNT machine the psychrometric errors remain and may be due to the same problem noted in defect 021.

MJWitte 99/09/09
Tested with new 99.09.09 exe on both WinNT and Win95. All looks OK now.

Workaround

Mike,

I could not reproduce this on a machine (Win95) using the EnergyPlus.exe from the LicensedDevelopers subproject and the TermReheat deck from the ExampleFiles of LicensedDevelopers....

Note that the "psych errors" in your example defect output files are really related to the NaN errors that you also reported in defect 21.

Linda

Fix

See explanation in Defect 21.

External Ref: 22
Addressed in 99.09.16 Build of EnergyPlus
Last build tested: 99.08.27 Build of EnergyPlus

Plant and global outputs for beta 1 (CR #811)

Added on 1999-11-23 09:18 by @mjwitte

Description

MJW 99.11.23

Testing HVAC and finding key output variables unavailable. We should really try to get some of these in before beta 1:

Purchased Cooling Energy/Rate
Purchased Heating Energy/Rate
Fred B will address the above
Plant Supply Side Heating Energy/Rate
Plant Supply Side Cooling Energy/Rate
Dan F will address the above 2
These have been moved to beta 2

I know we talked about energy meters once - do we have any way of getting total electricity and total gas for the building and HVAC combined?
Energy meters is in Beta 2. Will not try to accomplish above before then. (Will hopefully be early in Beta 2 cycle)

MJW 99.11.30 also . . .
Pump:Variable Speed Energy/Rate
Fred B will address the above

Fix

I've added

Purchased Air Heating Energy[J]
Purchased Air Heating Rate[W]
Purchased Air Cooling Energy[J]
Purchased Air Cooling Rate[W]

to PURCHASED AIR and

Purchased Chilled Water Energy[J]
Purchased Chilled Water Rate[W]

to PURCHASED CHILLED WATER, and

Purchased Hot Water Energy[J]
Purchased Hot Water Rate[W]

to PURCHASED HOT WATER, and

Variable Speed Pump Energy[J]
Variable Speed Pump Power[W]

to PUMP:VARIABLE SPEED.

I haven't altered any of our input files, but I have tested that
these outputs work and produce reasonable numbers.

Fred Buhl

External Ref: 56
Addressed in 99.12.17 Build Beta1
Last build tested: 99.11.17 Build of EnergyPlus

Purchased air temperature control shift by 0.26C in Build 011-014 (CR #835)

Added on 2000-03-30 10:12 by @mjwitte

Description

MJW 00.03.30

The Bland analytical conduction tests are shoeboxes with purchased air with constant heating and cooling setpoints of 20C and 50C. It is driven with constant outdoor air temps of 0C, 20C, 50C, and 70C.

Prior to Beta2 Build 011, the mean air temperature would settle out at 20.00011, 20, 50, and 49.999 in response to the four driving temps.

With Beta 2 Build 011-014, the temps are now 19.73886, 20, 50, and 50.26328.

Why the 0.26C offset in the temperature control?

Similar shifts seen in PurchAir sample run as well.

See files in Test Files:Defect Files 102-*

Fix

The purchased air module was calculating zone air mass flow rate
with the equation:

MassFlow = ZoneLoad / DeltaEnthalpy

Replacing it with

MassFlow = ZoneLoad / (CpAir*DeltaTemp)

fixes the problem.

The problem arose when the CpAir in ZoneTempPredictorCorrector was
"dried out".

MJW 00.03.31
Wow! It's even better than before. Instead of 20.00011, 20, 50, and 49.999, it's 20, 20, 50 and 50. Very nice.

External Ref: 102
Addressed in 00.03.30 Build 015, Beta 2
Last build tested: 00.03.30 Build 015, Beta 2

Create standalone input macro utility from DOE-2 BDL macro code (CR #819)

Added on 1999-12-06 10:46 by @mjwitte

Description

MJW 99.12.03

Take the DOE-2 BDL macro processing code (input variables, if blocks etc.) and make a standalone utility that can be used to preprocess EnergyPlus input files to allow for parameter substitution, conditional inputs, etc.

At the same time, fix the elseif problem where every true block in an elseif gets executed (current bu in DOE-2.1E BDL processor).

Fix

Fred Buhl accomplished this in April.

External Ref: 66
Addressed in 00.05.05 Beta 3 (Before Surface Change) by @mjwitte
Last build tested: 99.12.01 Build of EnergyPlus

Data dictionary needs to document max/min data also times should include minutes (CR #826)

Added on 2000-02-02 09:32 by @mjwitte

Description

MJW 00-02-02

In the eso file, when daily/monthly/environment report variables are selected, the data include min/max and times of min/max. These additional variables are not currently called out in the data dictionary at the top of the file.

Also, the times are currently integral hours. They should include the minutes as well, either as a separate number of by using fractional hours.

MJW 00.03.29
Daily and Monthly variables seem to be working OK as outlined above.

But if the same variable is requested with more than one time period (e.g. hourly and daily), error messages are generated in the err file, even though the data appears to be reported correctly in the eso:

** Warning ** The following Report Variables were requested but not generated
************* because IDF did not contain these elements or misspelled variable name -- check .rdd file
************ Key=, VarName=MEAN AIR TEMPERATURE

See file in Test Files:Defect Files:088-1zoneuncontrolled.*

External Ref: 88
Addressed in 00.03.29 Build 013, Beta 2
Last build tested: 00.03.29 Build 014, Beta 2

No version stamp in output files (CR #799)

Added on 1999-08-20 08:41 by @mjwitte

Description

All output files need to indicate the program name and a version stamp and possibly a datetime stamp, too. Some have the program name, but that's all.

This will be addressed sometime before the Beta 1 release.

External Ref: 23
Addressed in 99.12.01 Build of EnergyPlus
Last build tested: 99.02.25 Build of EnergyPlus

Fin Origin Problem - y adjusts both x&y (CR #803)

Added on 1999-10-28 14:58 by @mjwitte

Description

MJW 99.10.28

The x-coordinate for Vertex 1 on a fin appears to be ignored, and the y-coordinate appears to adjust both the x & y positions of the fin origin.

see test files:defect files:042-case630.idf, dxf

See work around and solution...

MJW 99.11.10

With a fixed input (solar=+1, and schedules correct), verified that the fin placement for the simulation appeared to be working properly, just the dxf picture showed the fins in the wrong place.

revised 042-case620.idf checked in.

MJW 99.11.10
Indeed, it was just an error in the dxf picture, the thermal answers did not change. Fixed dxf checked in.

Workaround

This deck has a couple of problems. No Trans schedule is specified for the fins or overhangs. There is also no SCHX schedule which is used in Infiltration.

Fix

I believe the fins are now "fixed" for at least building north=0 and zone north=0. Need to implement the "north arrow" to help make sure others around the axis work equally well.

External Ref: 42
Addressed in 99.11.17 Build of EnergyPlus
Last build tested: 99.10.28 Build of EnergyPlus

Nominal U calculation for Windows (CR #837)

Added on 2000-04-06 07:26 by @lklawrie

Description

The "Constructions" report for non-Windowglass constructions has a nominal U value calculation that is shown (Thermal Conductance). It would be good to add this reporting to the similar "construction" report for Windows. I'm sure there is still a lot of guidance that looks at U-Values for windows as a guideline for energy efficiency (such as the Federal Government's guidance). We should try to provide appropriate information where we can.

MJW 00.06.13
I would agree. ASHRAE Std. 90.1, for example, specifies minimum acceptable U-values. Also, it would be good to report the U-values with and without nominal film coefficients (include both inside and outside films) and include in the report what was assumed for the films.

FW: will implement in beta4

Fix

Added calculation of nominal U-value for windows for ASHRAE winter conditions (no solar, outside temp = -17.8C (0F), inside temp = 21.1C 970F), 6.71 m/s(15 mph) wind speed. Calculation uses same window heat balance routines that are used in the time step calculation, but for the winter conditions, and for interior and exterior blackbody surround at inside air temp and outside air temp, resp.

External Ref: 109
Addressed in 00.09.25 Beta 4, Build 008 by F Winkelmann
Last build tested: 00.04.05 Beta 2 Release

Component vs. Node Data (CR #796)

Added on 1999-03-03 13:56 by @lklawrie

Description

Node Data currently contains Max/Min that are usually assigned to the outlet side of a component. This data is really particular to the component itself and this assignment to the nodes should be revisited prior to final release.

Fix

Yes that's right . A design decision was made to put the component
flow max and min on the component outlet node. Other max and mins
(temperature and humidity ratio) aren't really being used yet. The
reason for doing this was that the component data is not easily available
to the loop solver whereas the node data is available. Still, it is a
somewhat ad hoc procedure. Let's think about this again & discuss
it at our next meeting (Golden CO, May 2000).

FB 3/31/2000

We've let this as is.
FB 02/25/2002

External Ref: 19
Last build tested: 99.02.25 Build of EnergyPlus

ReadVars (from Beta Survey) (CR #830)

Added on 2000-03-28 05:53 by @lklawrie

Description

• problems with batch of postprocessor RUNREADESO (in DOS-mode under NT 4.0). using file RUNREADESO.BAT
  "ReadVarsESO.exe < eplusout.inp > nul"
  and file EPLUSOUT.INP i.e.
  "eplusout.eso
  eplusout.csv
  6
  14
  25
  53
  57
  0"

External Ref: 96
Addressed in 00.03.28 Build 011, Beta 2
Last build tested: 00.03.23 Build 010, Beta 2

Keep directory for input files (CR #842)

Added on 2000-04-01 14:58 by @lklawrie

Description

Each time you "browse" for an input file, it goes back to some system default -- would be nice to keep the "last directory".

4/3/00 -- maybe it was just something about the machine I was on. It was fine on my work desktop this morning....

3/8/2001 -- Looks like if you have EP-Launch on disk A but are running on disk B -- then this occurs.

I have and am running EP-Launch from my E drive but the input files are on D. Each time I have to browse for a new one, it goes back to C:\My Documents to start.

MJW-09MAR01
Under Windows 2000, the behavior is different, it does remember the last working directory, even when on a different drive. I've noticed this change in other software, too.

External Ref: 104
Addressed in 01.03.23 V1.0, Build 003 by @mjwitte

Getting erroneous error "Zone is not convex (CHKBKS)" (CR #804)

Added on 1999-11-01 09:45 by @mjwitte

Description

MJW 99.11.01

With "solar distribution = +1" (BUILDING), getting "Zone is not convex (CHKBKS)" error on a fully enclosed shoebox with two windows. If I recall correctly the way BLAST treated SD=+1, the shoebox should be considered convex?

test files:defect files:043-case610a.idf, err

Same thing happens with version 99.10.13 (test files are from this version)

Fix

MJW 99.11.04

Floor vertices were described clockwise instead of counterclockwise, which confused the geometry. With fixed vertices, no error message occurs.

Is there a way for eplus to recognize incorrect vertices?

External Ref: 43
Last build tested: 99.10.28 Build of EnergyPlus

NaN appearing in eso files on MJW WinNT, Results changing in 4th figure on MJW Win95 (CR #797)

Added on 1999-08-20 08:24 by @mjwitte

Description

Executed GeometryTest.idf example file and got "NaN"s in the eso file, e.g.:

Line 563 StarTeam ExampleFiles: 25,19.15081
Line 563 GARD Run: 25,NaN

Same thing happend with TermReheat

Using files from StarTeam:EnergyPlus:LicensedDevelopers:ExampleFiles
GeometryTest.idf [Version #1, 03 Jun 1999 13:27:34
TermReheat.idf [Version #1, 29 May 1999 12:20:48

EnergyPlus from LicensedDevelopers:ProgramFiles
EnergyPlus.exe [Version #3, 26 Jul 1999 12:50:26

**NOTE the build number assigned here is wrong, but I had to choose something . . .

MJWitte 99/09/03
Tested on two machines:

A. WinNT 4.00.1381 on a Dell Dimension XPS R400, Pentium II 400 MHz, 64MB ram

B. Win95 on a Gateway 2000 P5-133, Pentium 133 MHz, 32MB ram

On the WinNT machine, the results were still as noted above with NaNs in the eso file for both TermReheat and GeometryTest.

On the Win95 machine:
The results for GeometryTest were identical to the sample files.
The results for TermReheat had no NaNs, but some values were different in the 4th figure:

 Line 579 StarTeam ExampleFiles:  61,21.50875
 Line 579 GARD:  61,21.50869
 Line 6366 StarTeam ExampleFiles:  61,19.54455
 Line 6366 GARD: 61,19.56093

The eso file for this run (done on 99/08/27) is in the defect files directory as 021-GeometryTest Win95.eso

Tested on the WinNT machine using the new 99.08.27 build and got the same results.

Also, per Linda's suggestion, tried installing VFRUN60I.exe runtime library on the NT machine. This made no difference in the results.

MJWitte 99/09/08
Tested suite of idfs from Test Files:Input Files and compared to results
in Test Files:Output Files:Real DVF

Results seem to point to something solar or shading related . . .

1zoneuncontrolled: identical
ctftestspart1: NaNs in summer d-day, winter d-day identical
ctftestspart2: NaNs in summer d-day, winter d-day identical
dualduct: NaNs in summer d-day, differences in winter d-day
geometrytest: NaNs in summer d-day, winter d-day and annual identical (5/1-5/10)
materialtest: identical
solarshadingtest: NaNs in "PHOENIXWINWSUM" d-day
solarshadingtestann: NaNs throughout annual (7/1-7/7)
surfacetest: identical
termreheat: NaNs in summer d-day, differences in winter d-day
vavsimple: NaNs in summer d-day, differences in winter d-day
windowtests: NaNs in summer d-day, winter d-day identical

MJWitte 99/09/09
Tested with new 99.09.09 exe on both WinNT and Win95. All looks OK now.

Workaround

Did not reproduce (see conditions on Defect 22)

Fix

This was caused inadvertantly by Fred W and new shading calcs. Initializing CTHETA, CosIncAng, and new AOSurf1 and AOSurf2 seems to have solved the problem for the moment. We should look at these calculations and make sure the proper things are being set.

External Ref: 21
Addressed in 99.09.16 Build of EnergyPlus
Last build tested: 99.08.27 Build of EnergyPlus

Floating Overflow with OUTSIDE CONVECTION=1 (CR #807)

Added on 1999-11-03 15:00 by @mjwitte

Description

MJW 99.11.03

Setting OUTSIDE CONVECTION ALGORITHM = 1 caused a floating overflow in HEATBALANCESURFAC line 2428 on day 66 of the simulation - using drycold.wea

With chanute.wea, floating overflow in HEATBALANCESURFAC line 2423 on day 341 of the simulation

test files:defect files:047-case195cnvc.idf,eso,log

Using exe dated 99.11.03 7:46 am

View new subproject under Defects for further work on this.

Fix

Incorrect translation from OCNVCO (BLAST routine). HBSurfMan was corrected, routine InitOutsideConvectionCoeff was in error.

External Ref: 47
Addressed in 99.11.17 Build of EnergyPlus
Last build tested: 99.10.28 Build of EnergyPlus

TermReheatOA annual fails with chanute.wea and drycold.wea (CR #815)

Added on 1999-11-30 12:14 by @mjwitte

Description

MJW 99.11.30

TermReheatOA run for entire year with three weather files:

drycold.wea - aborts with error message " ** Fatal ** No equipment found in FindLoadRangeAndEquipLists"

chantue.wea - bombs with "run-time error M6201: MATH

• exp: DOMAIN error"

IL Chicago TMY2.epw - runs to completion

Test Files:Defect Files

060-TermReheatOAAnn-drycold (idf, err, eio, eso, log)
060-TermReheatOAAnn-chanute (idf, err, eio, eso, log)

EnergyPlus.exe Build 008

See Solution Tab for further descriptions/information.

MJW 99.12.06

Another related symptom . . .

A test run of the TermReheatOA system fails when the heating
setpoint of Zone 1 (Russ Resistive Zone) is increased from 20C to
25C. The test run incorporates no other changes to the base case,
which runs successfully. The test run consistently fails on the 11th
hour of 4/11. The test run was performed using the 12/1 version of
EnergyPlus with the Chicago IL TMY.epw weather file.
Input: 060-TermReheatOA-1310.idf

Workaround

LKL: In Chanute it is on April 5, Hour 17, and is caused by NaNs:
Traceback:
WATERCOILSIMULATI 1436 HVACWaterCoilComponent.f90
WATERCOILSIMULATI 203 HVACWaterCoilComponent.f90
SIMAIRSERVINGZONE 649 SimAirServingZones.f90
SIMAIRSERVINGZONE 550 SimAirServingZones.f90
SIMAIRSERVINGZONE 148 SimAirServingZones.f90
HVACMANAGER_mp_SI 387 HVACManager.f90
HVACMANAGER_mp_SI 297 HVACManager.f90

If you start the Chanute weather file on 4/5, it will bomb during the second or third warmup step. If you start the Chanute weather file on 4/4, it completes successfully....
HVACMANAGER_mp_MA 119 HVACManager.f90
HEATBALANCEAIRMAN 482 HeatBalanceAirManager.f90
HEATBALANCEAIRMAN 117 HeatBalanceAirManager.f90
HEATBALANCEMANAGE 161 HeatBalanceManager.f90
SIMULATIONMANAGER 154 SimulationManager.f90
ENERGYPLUS 124 EnergyPlus.f90
Unknown Unknown Unknown

Fix

All the problems traced back to HVACWaterCoilComponent, SUBROUTINE CalcDetailFlatFinCoolingCoil.

1. When there is a very low entering water mass flow (.0001) the detailed coil model has numeric problems (divide by zero). The fix is to check for low water flow and force the coil to be off if it is too low.

2. This isn't really a defect in the model, but it can be dealt with here. The input has the HVAC system scheduled off on some very cold spring nights. When the system switches on in the morning, it blows cold air through the cooling coil: the entering air temperature is below the entering water temperature and the coil acts like a heating coil - it raises the leaving air temp and depresses the leaving water temp. This results in a heating load passed to the chilled water loop, which generates the famous fatal error: " ** Fatal ** No equipment found in FindLoadRangeAndEquipLists". Again, the solution is to force the coil to be off in this case.

TermReheatOA now runs to completion in all 3 annual cases mentioned by Mike. However things aren't perfect - the detailed coil model goes over its iteration limit at least 5 times in all the runs and one of the runs, 060-TermReheatOA-1310.idf, generates several psychrometric error messages.

External Ref: 60
Addressed in 99.12.17 Build Beta1
Last build tested: 99.12.17 Build Beta1

Floating overflow in water coil on cold design day in DualDuctConstVolDamper (CR #834)

Added on 2000-03-28 12:05 by @mjwitte

Description

MJW 00.03.28
Added a cold -30C constant temp no-sun design day to DualDuctConstVolDamper. Got this crash:

forrtl: error (72): floating overflow
Image PC Routine Line Source
EnergyPlus.exe 004E07C3 WATERCOILS_mp_CAL 1497 HVACWaterCoilComponent.f90

See files in Test Files:Defect Files:
100-*

Happening here:
UADryCoil = (WaterCoil(CoilNum)%TotCoilOutsideSurfArea - SurfAreaWet) / (WaterCoil(CoilNum)%TotCoilOutsideSurfArea * &
(TubeFoulThermResist + DryCoilInThermResist + CoilToAirThermResistDrySurf))
===> DryCoilCoeff = EXP(UADryCoil*DryCoilCoeff1)
K1 = WaterMassFlowRate * cpcw(TempWaterIn) * ConvK * (DryCoilCoeff - 1) / &
(WaterMassFlowRate * cpcw(TempWaterIn) * ConvK * DryCoilCoeff &
- AirMassFlow * MoistAirSpecificHeat)
Values:
UADryCoil 4.9898628E-02
DryCoilCoeff1 2105.479

Workaround

a small flow tolerance had to be set with the run tests for the detailed coil model

External Ref: 100
Addressed in 00.05.05 Beta 3 (Before Surface Change) by Rich Liesen
Last build tested: 00.03.23 Build 010, Beta 2

Plant and global outputs needed (CR #820)

Added on 1999-12-06 12:02 by @lklawrie

Description

Plant Supply Side Heating Energy/Rate
Plant Supply Side Cooling Energy/Rate
Dan F will address the above 2
These have been moved to beta 2

Fix

Report Variables added to Supply Side

6/24: Please detail which variables were added as a result of this change.

6/30: The following report variables were added:

Plant Loop Cooling Demand[W]
Plant Loop Heating Demand[W]
Debug Unmet Plant Loop Demand[W]
Debug Plant Loop RemDemand[W]
Debug Plant Loop Bypass Fraction
Debug SSInletNode Flowrate[kg/s] - Loop Inlet Flow Rate
Debug SSInletNode Temperature[C] - Loop Inlet Temp
Debug SSOutletNode Flowrate[kg/s] - Loop Outlet Flow Rate
Debug SSOutletNode Temperature[C] - Loop Outlet Temp

The Debug variables are used for OSU debugging purposes.

External Ref: 68
Addressed in 00.07.05 Beta 3, Build 011 by Brandon Anderson
Last build tested: 99.12.01 Build of EnergyPlus

NT Underflow, related to report variables? (CR #810)

Added on 1999-11-23 09:00 by @mjwitte

Description

MJW 99-11-23
With Win98 Exe (99.11.22), get a math error in unknown routine.
With WinNT Exe (99.11.22), get underflows reported.

Files in Test Files:Defect Files (idf, eso, log)

055-VAVSimple-rev-drycold-a - fails, drycold.wea present but not used

055-VAVSimple-rev-noweath-a - runs OK, idf identical to above, but no weather file present

055-VAVSimple-rev-drycold-b - runs OK, idf changed - one additional report variable turned on, drycold.wea present but not used

With latest checkin, Build 007, I cannot reproduce this problem (LKL)

MJW 99.11.29
Retested with Build 006/007NT (99.11.23), problem still present.
Tested with Build 007/007NT (99.11.29) and the problem is gone.

External Ref: 55
Addressed in 99.12.01 Build of EnergyPlus
Last build tested: 99.11.17 Build of EnergyPlus

Array bounds exceeded-Uncontrolled and controlled zones in same run (CR #806)

Added on 1999-11-02 13:24 by @mjwitte

Description

MJW 99.11.02

This run crashes in ZONETEMPPREDICTOR with "array bounds exceeded" error.

test files:defect files:046-case960.idf, log

same thing happens with versions 99.10.05, 99.10.13, 99.10.28, and 99.11.02

MJW 99.11.03

With latest exe (99.11.03 7:46 am) the array bounds error is gone, but now there is a "floating overflow" in HEATBALANCESURFAC
line 1951. On NT with Chanute.wea, drycold.wea, and " IL Chicago TMY2.epw" all get same error.

MJW 99.11.05

With lastest exe (99.11.04 4:36 pm) the workaround works - i.e., control the uncontrolled zone with a control type of zero. But the original run when a completely uncontrolled zone is mixed with a controlled zone still gives a floating overvlow (on NT with drycold.wea and chanute.wea).

MJW 99.11.15
With latest exe (99.11.15) this runs now (on an NT machine) all the way to competion, both with chanute and drycold weather.

With latest NTexe (99.11.15) this still crashes in HEATBALANCESURFAC 1952, both with chanute and drycold weather.

99.11.17 -- Found a possible initialization problem. Crossing my fingers that this fixes things (for a while at least)

Workaround

Dont mix uncontrolled and controlled zones in same run.

Only use the NTEnergyPlus.exe on this one until we get it figured out.

Fix

Detect if the zone to be updated (air temperature) is a controlled one or not. Update appropriately.

External Ref: 46
Addressed in 99.11.17 Build of EnergyPlus
Last build tested: 99.11.17 Build of EnergyPlus

Array bounds exceeded with all NoSun surfaces (CR #809)

Added on 1999-11-04 15:01 by @mjwitte

Description

MJW 99.11.04

If all surfaces in a run are set to NoSun, the run fails with an array bounds exceeded in HEATBALANCESURFAC line 2049. If one surface is set to SunExposed, the run will complete.

test files:defect files:049-1ZoneUncontrolled-nosun.idf, log
used chanute.wea weather
EnergyPlus.exe 99.11.04 1:06 pm
NTEnergyPlus.exe 99.11.04 1:26 pm

External Ref: 49
Addressed in 99.11.17 Build of EnergyPlus
Last build tested: 99.10.28 Build of EnergyPlus

Beta2 Build008 increased BESTEST case 195 loads by 1.936% (CR #829)

Added on 2000-03-23 08:56 by @mjwitte

Description

MJW 2000.03.23
Beta2 Build008 vs. Beta2 Build006 increased BESTEST case 195 heating and cooling loads by 1.936% every hour. Mean air temperatures are identical out to four or five figures.

See test files:defect files:094*
The zip file is an excel template to compare versions for this run.

This appears to be due to the change in CpAir calcuation in ZoneTempPredictorCorrector from a constant of 1004 to being based on zone humidity ratio and other factors. This is been sent for verification to Rich and Fred B.

Workaround

This is due to the Cp used for the calculation of the sensible load. IT was a moist Cp and should have been dry. There needs to be a consistent set of Cp's used throughout the sensible calculation. This is not quite complete in the Heat Balance.

External Ref: 94
Addressed in 00.05.05 Beta 3 (Before Surface Change) by Rich Liesen
Last build tested: 00.03.08 Window5 Calcs

Divide by zero with chiller capacity = 0 (CR #836)

Added on 2000-03-30 11:23 by @mjwitte

Description

MJW 00.03.30
In TermReheat, setting Big Chiller to zero capacity causes a divide by zero error.

Performing Simulation
forrtl: error (73): floating divide by zero
Image PC Routine Line Source
EnergyPlus.exe 0051D47E CHILLERBLAST_mp_C 521 PlantChillerBLAST.f90

See Test Files:Defect Files:103-*
run with Chicago IL TMY2.epw

Fix

This and other inappropriate 0.0's are checked for in Chiller:BLAST, Chiller:Const COP, and Boiler:Simple. Further perusal of this code should be done to make sure a divide by zero is detected...

These are checked during input and the run fails.

External Ref: 103
Addressed in 00.04.01 Beta 2, Build 017
Last build tested: 00.03.30 Build 015, Beta 2

End of Line Problem (CR #825)

Added on 1999-12-09 09:47 by @lklawrie

Description

See Weather manager header code. InputProcessor needs to do something similar.

This was also addressed by a beta tester:
syntax-debugger for *.idf file doesn't recognize missing ";" or ",",
thus producing sometimes misleading error codes in eplusout.err

External Ref: 83
Addressed in 00.03.23 Build 009, Beta 2
Last build tested: 00.03.28 Build 011, Beta 2

Conduction error with TIMESTEP IN HOUR=1 (CR #812)

Added on 1999-11-23 12:06 by @mjwitte

Description

MJW 99.11.23

One of the cases in the BRE/BEPAC analytical conduction tests (ref. paper by Bland) is a cube of 5 cm thick aluminum driven by a step change weather file which goes from 0 to 20 to 70 to 50 to 0 C for months at a time. Heating setpoint is 20C, cooling setpoint is 50C

With TIMESTEP IN HOUR=2 or more, the surface temperatures track the outdoor conditions as expected.

With TIMESTEP=1, something goes awry and when it is 70C outdoors, the mean air temp is 20C, the surface temps are 18C and the heat is on!

EnergyPlus version: 1.0, Beta 1, Build 005 (99.11.22)
same results with NT exe.

Build 008 -- hopefully, fixed!
The errors start from the first hour of first day.....not sure what the problem is. (Build 007)

In Test Files:Defect Files:
057-Test 10-1 - timestep=1
057-Test 10-1b - timestep=2
in the xls files, look at the "Composite" tab which graphs the temperatures

In Test Files:Weather Data:
"Bland Excitation 1.epw" is the weather file to use (Bland is the test author's name!)

MJW 00-09-06
Re-tested this with Beta 4 Build 003 and it's still ok.

MJW 12MAR01 - Added test suite name and edited initial problem statement to fix error in temperature sequences ( noticed while preparing BS'01 paper :-)
Test Suite --> BEPAC/Bland Analytical Conduction

Workaround

Dont use Timestep=1....:-)

Fix

This was a problem in the CTF calcs for one of the constructions. It quit too early and didnt end up with enough terms (I think -- this is the comment I should have put in then.... LKL)

External Ref: 57
Addressed in 99.12.01 Build of EnergyPlus
Last build tested: 00.08.16 Beta 4, Build 003

Output of cooling coils is negative. (CR #823)

Added on 1999-12-08 17:40 by @lklawrie

Description

Output produced in the .eso file shows cooling coil values to be negative. They are set as -totalload -- is total load really a cooling load and positive or is this an error. In either case, should be corrected and positive numbers reported in the .eso file.

External Ref: 75
Addressed in 99.12.17 Build Beta1
Last build tested: 99.12.01 Build of EnergyPlus

Docs don't work with Acrobat 3 (CR #822)

Added on 1999-12-08 08:10 by @mjwitte

Description

Docs don't work with Acrobat Reader 3.01. Main menu doesn't work well at all and docs opened via the main menu don't display. Docs opened directly have problems with graphics and title bars displaying as all black.

Fixed by adding an additional file for Acrobat3 users (Different EPlusMainMenu) as well as embedding all fonts in documents.

External Ref: 74
Addressed in 99.12.17 Build Beta1
Last build tested: 99.12.01 Build of EnergyPlus

Use the eplusout.end file to detect errors in a run. (CR #844)

Added on 2000-04-01 15:00 by @lklawrie

Description

The dos window may fly by so fast that you're not sure if there was an error or not. If EP-Launch would check the eplusout.end file for completion -- then it could tell if there was an error or not.

External Ref: 106
Addressed in 01.03.23 V1.0, Build 003 by @mjwitte
Last build tested: 00.04.03 Beta 2, Build 018

Build 011 caused big change in DualDuct mass flows for some time steps (CR #821)

Added on 1999-12-06 14:35 by @mjwitte

Description

MJW 99.12.06
Comparing outputs for the DualDuct run for Build 011 vs. Build 010

With the latest exe, there are significant changes in some variables:

NODE_4:System Node MassFlowRatekg/s
NODE_7:System Node MassFlowRatekg/s
SIMPLEHEATINGCOIL:Sensible Water Coil RateW

For these times steps:
7/21 14:50 changes as high as +40%
7/21 15:10 changes as high as -40%

Files:
072-DualDuct*

Fix

These changes are expected with the new algorithms and fixes that took place.

MJW 00.03.29
Not sure I agree, but with the many changes in HVAC for Beta 2, this doesn't really matter anymore.

External Ref: 72
Addressed in 00.03.28 Build 011, Beta 2
Last build tested: 99.12.01 Build of EnergyPlus

Multiple Systems -- create duplicate schedules (CR #840)

Added on 2000-01-28 12:57 by @lklawrie

Description

If you have more than one system, the counter on producing the Schedule variables restarts with the new system -- this should be cumulative. Probably does it with plants too. Should not be a problem with Buildings as I dont think we allow multiple buildings any more....
'

Fix

Dont create system schedules.

External Ref: 87
Addressed in 00.03.28 Build 011, Beta 2
Last build tested: 99.12.17 Build Beta1

Chiller COPs too high (CR #813)

Added on 1999-11-30 09:44 by @mjwitte

Description

MJW 99.11.30

Nominal COP for CHILLER:BLAST set to 2.75, but getting chiller COPs of 5.7 to 12.9. All other chiller inputs are identical to TermReheat.idf

Test Files:Defect Files
058-TermReheat-Base Bldg (idf, rvi, csv, xls)

Weather File: drycold.wea

EnergyPlus.exe (Build 008, 99.11.30)

Fix

MJW 00.06.07 Beta 3 Build 007
COP's appear to be behaving correctly now.

External Ref: 58
Addressed in 00.06.08 Beta 3, Build 008 by @mjwitte
Last build tested: 00.06.05 Beta 3, Build 007

Missing comma after BUILDING name causes array bounds error (CR #814)

Added on 1999-11-30 10:19 by @mjwitte

Description

MJW 99.11.30
Missing comma after Building name caused array bounds exceeded error.

Test Files:Defect Files

059-TermReheatOA-2246 (idf, log)

drycold.wea

External Ref: 59
Addressed in 99.12.01 Build of EnergyPlus
Last build tested: 99.11.17 Build of EnergyPlus

Install Password Entry (CR #839)

Added on 2000-04-06 07:37 by @lklawrie

Description

If possible, allow for a "right click", paste operation. Verify that ctrl-V works.

Ctrl-V works here. Right click apparently doesnt. I contacted WISE but no one ever answered the post to the news group.

From Dru: When I right click, all the items are greyed out.

External Ref: 111
Addressed in 00.07.20 Beta 3 Release by @lklawrie
Last build tested: 00.04.05 Beta 2 Release

DUAL SETPOINT WITH DEADBAND crashing in summer with PURCHASED AIR (CR #801)

Added on 1999-10-25 12:00 by @mjwitte

Description

MJW 99-10-25
See test files:defect files:038-case600d4.*

This is a shoebox with a couple of windows with purchased air from the BESTEST suite. It runs fine with SINGLE HEATING COOLING SETPOINTcontrol type. But with DUAL SETPOINT WITH DEADBAND, it run the winter design day OK, and then crashes during the summer day in ZONETEMPPREDICTOR line 1114 (see log file).

Fix

This was possibly a number of things and though things may still be wrong in the code. The idf needs to be changed:

Specific Heat units now J/kg-K

Zone Volume Capacitance Multiplier statement needed to be added. That is now detected and set to 1.0

Fixed with .exe checked in on or after 10/27/99

External Ref: 38
Addressed in 99.10.28 Build of EnergyPlus
Last build tested: 99.10.28 Build of EnergyPlus

Better definition on output variables (CR #831)

Added on 2000-03-28 05:56 by @lklawrie

Description

Report Variable, Window1, Direct Solar [W/m▓], hourly;
Report Variable, Window1, Diffuse Solar [W/m▓], hourly;

• no error message in the audit.out or *.err,
• no output in the *.eso!?

The problem here is that the user is trying to determine the effects of solar on a specific surface whereas the Direct Solar variables are "environment" variables.

LKL 04Mar02
From Mike: I just ran a quick test and the report
command shown in the CR does generate a warning now, and there are
plenty of surface solar outputs now.

External Ref: 97
Addressed in 02.02.26 V1.0.1.031 by @lklawrie
Last build tested: 02.02.26 V1.0.1.031

Unable to view dxf files with AutoCad, Volo View and Word (CR #800)

Added on 1999-08-20 08:43 by @mjwitte

Description

Tried to open 1ZoneUnctonrolled.dxf, GeometryTest.dxf, and TermReheat.dxf from LicensedDevelopers:ExampleFiles:

Opened OK in Visio
Opened OK in Microstation

Would not open via "import" in AutoCad Release 13-c4a
"Table flags missing on line 22"

Would not open in AutoDesk Volo View Express 2000-84
"Drawing file unrecognized"

Would not open via ""insert picture"" in MS Word97 using ""AutoCAD Format 2-D"" converter
"An error occurred while importing this file"

Note (lkl): This is a 3D File -- using 3DFace blocks.

lkl (8/24/99):
Autodesk View (30 day demo) also cannot read it. But reading one (Geometrytest) in Microstation and exporting it to a DXF file from Microstation allowed Autodesk View to read. Sent file to Mike Witte to see if VoloView and/or Autocad can read that version.

mjw (8/24/99):
VoloView likes this file (the one transformed by Microstation). It
comes in with the following views available: top, bottom, front,
back, left, right, SW isometric, SE iso, NE iso, and NW iso.

Word likes this file. It shows the NE isometric view with a little
less elevation than the VoloView NE iso.

AutoCad Release 13 likes this file. It has complete view control and
can be edited.

mjw 8/27/99:
Tested build 99.08.27
1zoneuncontrolled, geometrytest, and termreheat dxf files all read OK in VoloView and in AutoCAD Release 13, not readable by 2-D Word convertor (as expected)

Fix

See EPlusDXF.doc

External Ref: 24
Addressed in 99.08.27 Build of EnergyPlus
Last build tested: 99.08.27 Build of EnergyPlus

Environment and Location Outputs - additional data, typo (CR #817)

Added on 1999-12-06 09:35 by @mjwitte

Description

MJW 99.12.06

In the eio file, there's a typo in the Location data dictionary "Latitiude"

In the eso file, for the date/time headers, add Day Type [Sunday - Saturday - Holiday - SummerDesignDay - WinterDesignDay](for Time Step, Hourly, and Daily outputs)

External Ref: 64
Addressed in 99.12.17 Build Beta1
Last build tested: 99.12.01 Build of EnergyPlus

Solar Distribution = -1 not correct? (CR #808)

Added on 1999-11-04 13:13 by @lklawrie

Description

Simple Shoebox with a couple of windows and large overhang. Solar Distribution =0, =1 give good correlation with BLAST results (uncontrolled zone, using zone temps). Solar Distribution =-1 does not. (Is same both with and without overhang).

Fix

This was a VERY SUBTLE mistranslation from old BLAST code. The correction is not perhaps the most elegant but gets the job done.

External Ref: 48
Addressed in 00.05.05 Beta 3 (Before Surface Change) by @lklawrie
Last build tested: 99.10.28 Build of EnergyPlus

Condenser loop demand not met in termreheat and cvbbrh (maybe others) (CR #833)

Added on 2000-03-28 11:46 by @mjwitte

Description

MJW 00.03.28
It doesn't look like the towers are working in TermReheat and CVBbRh (mabye others?).

See files in Test Files:Defect Files:

098-099-.
xls files format and do calcs on csv data.

Fix

Dan Fisher claimed this is an artifact of the way the towers are
being controlled right now. Since I don't quite understand this
and Dan intends to address the issue, I am lowering this defect's
priority and reassigning it to Dan.

Fred Buhl

MJW 00.06.07 In Beta 3 Build 007, the condenser loop no longer complains about unmet loads, but the towers do no function properly, either. See CR 912 now.

External Ref: 99
Addressed in 00.06.08 Beta 3, Build 008 by @mjwitte
Last build tested: 00.06.05 Beta 3, Build 007

Purchased hot water rate greater thanl heating loop heating demand in termreheat and cvbbrh (maybe others) (CR #832)

Added on 2000-03-28 11:17 by @mjwitte

Description

MJW 00.03.28
PURCHASED HEATING:Purchased Hot Water RateW is always greater than
HOT WATER LOOP:Plant Loop Heating DemandW
in TermReheat and CVBbRh (and maybe others).

The ratio of purch heat to heat demand ranges from
1.05 to 2.23 in TermReheat and from 1.05 to 1.57 in CVBbRh.

See files in Test Files:Defect Files:

098-099-.
xls files format and do calcs on csv data.

Workaround

Correct the pump input so that its calculated efficiency is less than
100%.

Fix

This turns out to be a feature combined with an input error. There is a
hot water circulation pump upstream of the purchased hot water
component. This pump would normally add heat to the water, hence
the "Purchased Hot Water Rate" output would be expected to be
lower than the "Plant Loop Heating Demand". But the pump input
is incorrect, as is indicated on the error file by:

• Warning ** Check input. Calc Pump Efficiency=296.55% which is
  bigger than 100%, for pump=HW CIRC PUMP

The efficiency grater than 100% causes the pump to extract heat
from the water stream rather than add heat. Thus the "Purchased Hot Water Rate" comes out higher than "Plant Loop Heating Demand".

I'm going to mark this defect as fixed. We still need to fix the input
files and maybe change the pump code so that a fatal error is given
ot the efficiency is not allowed to exceed 100%.

Fred Buhl

External Ref: 98
Addressed in 00.04.01 Beta 2, Build 017
Last build tested: 00.03.23 Build 010, Beta 2

Overhangs not working (CR #805)

Added on 1999-11-01 09:57 by @mjwitte

Description

MJW 99.11.01

Overhangs don't appear to be working. Run with and without overhang, no change in results.

test files:defect files:

043-case610a.idf, eso - base building without overhang
044-case610b.idf, eso - same building with huge overhang, no change in results

Same thing happens with version 99.10.13 (test files are from this version)

MJW 99.11.04
Aha! Need a ShadowTrans Schedule! It was blank, so it must have been defaulting to zero, thus turning off the overhang.

Workaround

Specify a ShadowTrans schedule.

Fix

Specify a ShadowTrans schedule. Provide error message so the user has a clue why it doesnt work.

External Ref: 44
Addressed in 00.03.28 Build 011, Beta 2
Last build tested: 99.10.28 Build of EnergyPlus

Zero used for undefined schedule (CR #802)

Added on 1999-10-27 14:29 by @mjwitte

Description

MJW 99.10.27
If INFILTRATION (or ELECTRIC EQUIPMENT, or ???, I haven't tried every internal load) refers to a schedule which is not defined in the idf,
the run completes with no errors as though the schedule was all
zeros.

See test files:defect files:

039-case195G1.idf, eso --> no electric equipment
039-case195G2.idf, eso --> electric equipment with valid schedule
039-case195G3.idf, eso --> electric equipment with undefined schedule

Fix

Formerly were warning errors, will now cause fatal errors before simulation.

Now, all building input is "gotten" before the fatal error is produced.

External Ref: 39
Addressed in 99.10.28 Build of EnergyPlus
Last build tested: 99.10.28 Build of EnergyPlus

View output files - when there arent any (CR #843)

Added on 2000-04-01 14:59 by @lklawrie

Description

If the run has errors, not all the output files are made, but the "View Outputs" generates an open for all possible....

External Ref: 105
Addressed in 01.03.23 V1.0, Build 003 by @mjwitte
Last build tested: 01.02.12 Beta 5.0 Release

Negative numbers in input -- should be positive (CR #824)

Added on 1999-12-08 17:46 by @lklawrie

Description

FBuhl: By the way, all chiller and cooling capacities seem to be input as
positive numbers. The load ranges seem to be the only negative loads
that we are inputting. If someone feels strongly that this should be
changed, I will do so. But we'll have to change all our plant inputs.

DFisher: I went back and forth on this a bit when I wrote the input syntax. The only thing required to get rid of the negative sign is an extra field on each load range line that indicates "HEATING" or "COOLING". Then the relevant 'GetInput' routines would have to be modified to read the field and change the signs for the cooling load range values as they're loaded into the arrays. Admittedly the trade-off is between clarity and conciseness.

Go with clarity and consistency for the user

10/3/2000 -- this has now become a priority -- it has been sitting in the "queue" since December 1999 (Beta 1). This (beta 4) SHOULD have been the last beta. We need to have our input ducks in a row...

7/30/2001
With the new plant code, I believe this is now a no-brainer. The new inputs specify whether the Load Range is a cooling or heating and this was the only place negatives were input for cooling. In addition, the code uses the absolute values here so even if the old way is input -- it will still work.

7/31/2001 LKL
Marking this as "fixed". Though still "allowed" in the standard Load Range Based Operation object, there are two new objects Cooling Load Range Based Operation and Heating Load Range Based Operation. These will not allow negative inputs in their range limits. The old one will infer whether it should be Heating or Cooling based on the inputs. Also, mixed ranges (both >0 and <0) are not allowed for a single object.

External Ref: 76
Addressed in 01.08.09 V1.0.1, Build 002 by @lklawrie
Last build tested: 99.12.01 Build of EnergyPlus

Detailed Convection Model (CR #828)

Added on 2000-03-16 06:35 by @lklawrie

Description

From Fred W:
This goes back to what InitInteriorConvectionCoeffs
is doing for detailed calculation
when surface-to-air temp difference, DeltaTemp,
is 0.0, which it is for first time step. It ends
up with HCONVIN = 0.0 for some surfaces,
including windows. >>Rick and Linda: do we really
want this?

Fix

2001.03.22 (RKS)

This has now been fixed so that a zero convection coefficient for the detailed model is not possible. If the coefficient drops below an arbitrary limit (0.1) then the value is reset to the lower limit. This corresponds to a delta T of about 0.000444 so it shouldn't affect to many results. Of course any change propagates. Here's the text used for the "reason for check-in":

Fix of CR 828 to avoid zero convection coefficients. Some minor differences occur in all test suite files, larger differences in the two CTF files. CTF1 changes are noticeable in the third design day because the number of warmup days changed. CTF2 is still completely out to lunch so changes there are not all that important as long as things haven't gone unstable.

External Ref: 93
Addressed in 01.03.23 V1.0, Build 003 by @RKStrand
Last build tested: 00.03.08 Window5 Calcs

Determine if we can make Aniso Sky the default model (CR #827)

Added on 2000-03-06 08:00 by @lklawrie

Description

We plan to use only Aniso Sky as the model in the final release. Can we eliminate the other model now OR should we (for beta 2) make Aniso Sky and eliminate the other model in Beta 3?

Suggest that this be part of GARD's Testing for Beta 2.

Fix

BESTEST suites with and without aniso sky model give reasonable changes in results. So, there doesn't appear to be any glaring errors in the aniso sky model. So it seems OK to make it the default.

External Ref: 92
Addressed in 00.04.03 Beta 2, Build 018
Last build tested: 00.03.06 HVAC for Beta 2

Chiller Load Problems - too high, incorrect load management (CR #816)

Added on 1999-12-02 14:55 by @mjwitte

Description

MJW 99.12.02
Test 2110 forces the fan system to run 24 hours per day during the week days to produce a cooling load. Chiller load assignments were made to have small chiller operating during off-peak hours (100 to 700 & 2100 to 2400 hours) and large chiller operating during peak hours (800 to 2000 hours).

Problem 1: Large chiller never runs, small chiller always carries the load.

Problem 2: Total cooling generated by the chiller (Chiller Evap Heat Trans Rate) any hour always is much greater than the Cooling Loop demand (30-40% greater).

Test Files:Defect Files:
063-TermReheat-2110 (idf, etc.)

Using drycold.wea weather file.

EnergyPlus.exe Build 010 (99.12.01)

Fix

MJW 00.06.07 Beta 3 Build 007
Chiller heat transfer rates now seem to be in line with the cooling loop demand. Load managements issues are still a problem - see CR 911.

External Ref: 63
Addressed in 00.06.08 Beta 3, Build 008 by @mjwitte
Last build tested: 00.06.05 Beta 3, Build 007