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2018-10-22 03:37:38 -0500 commented question Setpoint temperature schedule in Openstudio

Can you break your question into two separate questions for each of these unrelated points please?

2018-10-18 08:24:10 -0500 marked best answer Where are the default chiller curve coefficient coming from in OS?

As the name implies, I'm trying to understand what's the rationale behind the default curve that come with the chiller

Let's take for example a Chiller:Electric:EIR and look specifically at the EIRFPLR curve, that is the Electric Input Ratio as a function of the Part Load Ratio.

This curve is quadratic: $$EIR = a + b\times PLR + c \times PLR^2$$

OpenStudio has the following default coefficients: - $a = 0.06369119$, - $b = 0.58488832$ - $c = 0.35280274$.

It seems that it leads to a pretty efficient chiller, unless I'm missing something. I've compared it t:

  • the Comnet modeling guidelines here (Table 6.8.2-9: "Default Efficiency EIR-FPLR Coefficients – Water-Cooled Chillers" > Centrifugal)

  • DOE-2 Centrifugal/5.50COP from the E+ dataset (EnergyPlusV8-3-0\DataSets\Chillers.idf)

a b c
Comnet 0.171493 0.588202 0.237373
DOE-2 Centrifugal COP 5.50 0.222903 0.313387 0.463710
OpenStudio 0.063691 0.584888 0.352803

I end up with the following curves where I'm displaying COP (SI units) instead of EIR since it's more intuitive in my opinion.

COP=f(PLR)

Anyone can explain why it seems so much more efficient than the rest?

2018-10-17 02:48:26 -0500 answered a question Operating speed of OpenStudio

I'm no expert on this either, but OpenStudio Application is developed in Qt C++. A single thread is generally used to

2018-10-15 07:23:54 -0500 commented answer Can you load Schedule:File in OpenStudio?

@macumber: now may be the time to update your answer!

2018-10-09 14:06:05 -0500 received badge  Notable Question (source)
2018-10-08 09:50:57 -0500 commented question OpenStudio Plugin error visualizing surfaces

To achieve the fastest resolution possible, could you host your file somewhere (google drive, box, wetransfer, whatever)

2018-10-08 09:49:43 -0500 commented question OpenStudio Plugin error visualizing surfaces

Cross posting of https://github.com/NREL/OpenStudio/issues/3299. Unless you know for sure it's a bug, posting on UnmetHo

2018-10-04 03:56:53 -0500 commented question Any way to use biquadratic curve for EIR curve of PLR in Chiller?

Related to https://unmethours.com/question/34256/eirfplr-vs-eirfplrdt/

2018-10-03 16:08:45 -0500 marked best answer OpenStudio: should you add adiabatic pipes and bypass branches manually?

I noticed that OpenStudio tends to add automatically some adiabatic pipes in the plant loops even if you didn't put any, including:

  • A Supply outlet pipe
  • A Demand inlet pipe
  • A Demand bypass pipe
  • A Demand outlet pipe

Why is it adding a bypass only to the demand and not the supply?

It seems that OpenStudio checks whether you have included the inlet/outlet pipes and doesn't add them if there are already there. But it seems that it will always add a demand pipe, even if you do have one. Why?

Should/can you manually create the pipes?

2018-10-03 09:26:03 -0500 received badge  Popular Question (source)
2018-10-02 02:32:28 -0500 commented answer Chiller curve and AHRI test condition.

Xmin and Xmax shouldn't be both 7. Read the description here. "The biquadratic curve should be valid for the range of wa

2018-10-02 02:27:44 -0500 commented answer Plant Loop:Demand Side is storing excess heat the majority of the time

It should work properly with OutdoorAirWetBulb, but the temperature inputs need to match your cooling tower design. Offs

2018-10-02 02:26:01 -0500 commented answer Energy storage dispatch

Check the resulting, generated, IDF file to ensure that the objects were properly forward translated. And check the log,

2018-09-27 06:07:39 -0500 answered a question water heater sizing object missing in OpenStudio

WaterHeater:Sizing is not wrapper in OpenStudio yet. See Issue #669

2018-09-27 05:13:50 -0500 commented question Plant Loop:Demand Side is storing excess heat the majority of the time

Can you post a picture of the plant loop itself, so we can see what's on the supply and demand side? Have you tried sett

2018-09-25 02:46:50 -0500 commented answer E+, How to model a AHU double fan (supply air and return air)

You can check the expanded IDF, as well as the SVG to check if that sounds like what you want.

2018-09-24 09:10:08 -0500 commented question Plant Loop:Demand Side is storing excess heat the majority of the time

Can you describe your plant loop a bit? Is your pump set a "Continuous" or "Intermittent"?

2018-09-24 09:09:22 -0500 commented answer E+, How to model a AHU double fan (supply air and return air)

No sorry, I don't see any built in way to do this in E+ unfortunately, at least if said AHU is serving more than one zon

2018-09-21 07:04:19 -0500 commented answer E+, How to model a AHU double fan (supply air and return air)

You mean your AHU has a VRF coil in it (at the central level)? Does the VRF outdoor unit serve another coil?

2018-09-21 04:53:53 -0500 commented question How do I sign up in Unmet Hours

I can't delete it (no admin power), but I think you perhaps can as the original poster.

2018-09-21 02:43:39 -0500 commented question How to control WSHP Common Loop temperature

You might want to read my (non-answered) question Definitive right way to model a WSHP loop as I at least present the al

2018-09-21 02:40:24 -0500 answered a question Single-zone VAV heat pump in OpenStudio

First, you're right that OpenStudio's OS:AirLoopHVAC:UnitarySystem is missing the control type option SingleZoneVAV whic

2018-09-21 02:23:53 -0500 answered a question E+, How to model a AHU double fan (supply air and return air)

If I understand correctly, which I'm not sure I am, I'd say use an AirLoopHVAC to model the AHU to serve your zone(s) th

2018-09-21 02:21:18 -0500 commented question How do I sign up in Unmet Hours

I'm curious what's the deal here :) ?

2018-09-20 04:52:37 -0500 commented question Why do we need 7 design days ?

I personally tend to use both Condns WB=> MDB and DB=>MWB whenever I have cooling towers, regardless or whether I

2018-09-20 04:46:53 -0500 commented question Why do we need 7 design days ?

I personally tend to use both Condns WB=> MDB and DB=>MWB whenever I have cooling towers, regardless or whether I

2018-09-20 04:46:23 -0500 commented question Why do we need 7 design days ?

I personally tend to use both Condns WB=> MDB and DB=>MWB whenever I have cooling towers, regardless or whether I

2018-09-20 04:42:46 -0500 commented question Why do we need 7 design days ?

Try both, look at your peak cooling and sizing values, and decide for yourself. My advice is that when articulating the

2018-09-19 06:36:03 -0500 commented question Why do we need 7 design days ?

Tried both, look at your peak cooling and sizing values, and decide for yourself. My advice is that when articulating th

2018-09-19 02:26:12 -0500 commented question Why do we need 7 design days ?

To me that's duplicated from https://unmethours.com/question/17053/openstudio-weather-file-design-days/ see my answer th

2018-09-19 02:24:07 -0500 commented answer linux ide (editor) for energyplus idf files

Or winetricks like I said, especially if you don't have a windows installation.

2018-09-18 11:25:05 -0500 commented question linux ide (editor) for energyplus idf files

The current problem is the packaging that's inexistent. Zips provided don't run on my Ubuntu 16.04, and that means I'd h

2018-09-18 11:02:13 -0500 commented question EIRfPLR vs EIRfPLR&dT

Yeah I can't speculate any further than you on this one.

2018-09-18 03:09:38 -0500 edited answer linux ide (editor) for energyplus idf files

There isn't, neither for Linux nor Mac. Please take a minute to go upvote this feature request 6551 on E+ GitHub to show

2018-09-18 03:09:04 -0500 answered a question linux ide (editor) for energyplus idf files

There isn't, neither for Linux nor Mac. Please take a minute to go upvote this feature request 6551 on E+ GitHub to show

2018-09-18 02:58:42 -0500 commented question EIRfPLR vs EIRfPLR&dT

Specifically, I'm interested to see the entire set of curves IES VE uses. Because if they use two curves, CapFT and EIRf

2018-09-18 02:57:23 -0500 commented question EIRfPLR vs EIRfPLR&dT

Do you have a link to the IES reference manual perhaps? Because reading the DOE2.1 Engineers manual (see here around pag

2018-09-18 02:57:08 -0500 commented question EIRfPLR vs EIRfPLR&dT

Do you have a link to the IES reference manual perhaps? Because reading the DOE2.1 Engineers manual (see here around pag

2018-09-17 08:01:52 -0500 commented question EIRfPLR vs EIRfPLR&dT

Which object are you refering to? Chiller:Electric:EIR for eg uses 3 curves: CapfT, EIRfT, EIRfPLR (Engineering ref). It

2018-09-17 08:01:06 -0500 commented question EIRfPLR vs EIRfPLR&dT

Which object are you referingto? Chiller:Electric:EIR for eg uses 3 curves: CapfT, EIRfT, EIRfPLR (Engineering ref)

2018-09-17 05:43:42 -0500 commented answer how do I export Space name and SpaceType name into csv with an OpenStudio measure?

Thanks for reporting the typo, fixed in the answer now.

2018-09-17 05:43:09 -0500 edited answer how do I export Space name and SpaceType name into csv with an OpenStudio measure?

IIUC, you want a table with two columns: Space Name, and Space Type Name. As @adhilton mentioned, space.spaceType retur

2018-09-14 02:20:50 -0500 edited question OpenStudio v2.6 simulation fails since EnergyPlus update to v8.9

OpenStudio v2.6 simulation fails since EnergyPlus update to v8.9 The simulation was not failing until the update. After

2018-09-14 02:20:14 -0500 edited question OpenStudio v2.6 simulation fails since EnergyPlus update to v8.9

OpenStudio v2.6 simulation fails since EnergyPlus update to v8.9 The simulation was not failing until the update. After

2018-09-13 03:32:16 -0500 edited question Energy Related Costs, Annualized

Energy Related Costs, Annualized Our company is doing analysis on different products (i.e. different wall configurations

2018-09-13 03:31:18 -0500 commented question Too high temperature

Do you have any infiltration or ventilation defined? If you have a very insulated box with no infiltration or ventilatio

2018-09-13 03:28:21 -0500 answered a question Weather file issues

Two weather-related things need to be loaded, and they should match: the weather file and the design days. Seems like yo

2018-09-13 03:25:27 -0500 edited question Weather file issues

Weather file issues Hello everyone, I am trying to do sizing runs using Open Studio 2.5. I exported the project file f

2018-09-13 03:23:34 -0500 answered a question openstudio four pipe beam unit

You're likely just using an outdated OpenStudio version, I added this object circa 2.5.2. (see PR#3031 effectively merge

2018-09-13 02:27:00 -0500 commented question EnergyPlus freezes/hang during simulation

Thank you for opening the Github Issue (and doing it by the book too!). I'm closing this question just for clarity since