Julien Marrec's profile - activity

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

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)

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.

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

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

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

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

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

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

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?

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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