Brian C's profile - activity

@David Goldwasser why is it that when I edit the OS:Lights object directly in the .osm file, I am unable to open the file again in OS Application by getting the following error: "Model with Version 1.11.0 IDD is not valid to draft stictness level"

Task

Hello,

I would like to learn how to specify load definitions by end-use within OpenStudio. For example, I have created process lighting definitions that I would like to see under Interior Lighting (process) not bundled under Interior Lighting. Same goes for electric equipment definitions for elevators, cooking equipment, etc. as all electric equipment is bundled under receptacle equipment.

Is this possible within OpenStudio platform? Can you do this by editing .osm file? How would you do this in the .idf if needed?

Thank you, Brian

Hello,

Has anyone else experienced problems running older version models in Open Studio v.1.11.0? While the Open Studio application does notify me that my model has been updated successfully to v.1.11.0, it is unable to run. Current Model Version: v.1.7.0 Updating Model Version: v.1.11.0

When updating the model in the OpenStudio application, the model does not load in SketchUp Make 2016 (nothing shows up). If I do not update the model through the OpenStudio application first, the model is able to load in SketchUp Make 2016 just fine. Nonetheless, either way I save the OpenStudio model, it is unable to be run through OpenStudio v.1.11.0.

Any recommendations? Thanks.

@Julien Marrec I have noticed the Pressure Rise input for each VRF Terminal Unit is 300 Pa from your script. I would like to reduce this to 150 Pa to match the project design documents. I was unable to find its location in your measure.rb file or in the HVAC.rb under resources to edit the input. How would you recommend me to edit changes such as these? Thanks

@egillmor thanks for the response and clarification. In my case I do have gas-fired DOAS, so I will stick with System 5. Also thank you @Julien Marrec for the script for VRF system here...it works well and is what I will use for my model when submitting for LEED.

I have currently modeled a VRF system for LEED v3-2009 for a facility in CO, USA under the following tariff structures: Xcel SG & CG-S. While the energy savings are great (~45%), the energy cost savings are not so great (~4%). My baseline currently adheres to System 5 (VAV with DX & HW Fossil Fuel Boiler). I have heard from other's in the industry that for Ground Source Heat Pumps jobs they have seen energy models using electricity as the source energy for heating in their baseline model to avoid "fuel-switching" in the proposed model.

What fuel source should be in the baseline energy model for heating if you are modeling VRF/Ground Source (electricity or natural gas)? I am unable to find any mention of how to address "fuel-switching" in ASHRAE 90.1 -2007 and would like to be certain before making a change.

Also, if you have modeled a VRF system, feel free to provide your energy/cost savings results!

Brian

Thanks. Your out.idf file will be helpful for me to manually create the objects in OS with your chosen parameters.

@Julien Marrec Thank you for link (unable to find it previously on BCL GUI in OpenStudio Application). With the script, is there a way to further specify the DOAS and/or VRF systems that are created. For example I only need 1 DOAS for my facility (not by floor) and a VRF system that has multiple CU's not just one large CU which I think the script is creating.

I am trying to model a VRF & DOAS w/ERV system for the first time in OpenStudio. I am running into what seems to be a common issue of having a lot of unmet hours when implementing a dedicated air system with VRF in OpenStudio.

It would be great to see how other's have done this so that I may be more confident that I modeling it as best as I can and ensure the VRF terminal units are performing the work. Any details regarding the necessary/important e+ inputs along with screenshots of layout would be helpful to see.

@David Goldwasser, thank you. I will download 1.11.4 next week. In the meantime I have the model running by changing from None to Continuous. Thanks again!

@David Goldwasser, thank you. If the bug cannot get fixed soon, could you recommend an alternative in the meantime for me to at least run the model. EPLaunch, older version of Open Studio?

I am running on a 64 bit windows 7 operating system. I created the model geometry with Sketchup 2016 (version 16.1.449) and Open Studio version 1.11.0. I deleted all previous versions of OpenStudio, Sketchup, EnergyPlus before installing to 1.11.0 and beginning work on this model as well. I sent the model along to the email you provided. Thanks for the help.

Hello,

I have recently updated Open Studio from a previous version and am experiencing the software crashing when I try to run the model on the Run Tab. It also crashes when I try and click on the Scripts Tab as well. I have noticed that in an untitled/blank Open Studio project I am able to click on the scripts tab. When I scan for tools, it discovers the following (3): EP-8-5-0, Radiance and Ruby. I have uninstalled everything and still no luck.

Has anyone else experienced this problem?

Thanks, Brian

Yes, sorry I updated question details to include this

I would like to know how to create a chiller curve for particular chillers in energy-plus. The two exact chillers I am trying to model are:

1. Standard Water-Cooled Chiller (WSC087 Std Chiller)
2. Magnetic Bearing Water-Cooled Chiller (WME500 MAG)

It would be helpful to have a step-by-step process of how you determine the coefficients for the three curves required. An example would be most useful, which references the energy plus documentation when needed.

Thanks, Brian

Yes I tried Lincoln's suggestion and didn't see much change as my direct evap kicks on after the units are unable to economize any longer as I'm seeing the highest RH during the hot summer months. Thanks for the responses though. Just out of curiosity, do you foresee direct evap becoming a controllable actuator anytime soon?

@Kyle Benne Is the Direct Evaporative Cooler able to be controlled by the EMS? We have tried to control this and it appears to not be controllable actuator.

thats a good idea, i'll give it a shot

@Kyle Benne

1. If I change the minimum fraction of outdoor to "always on discrete" will this only open to 100% when the direct evaporative cooler is enabled?

2. I figured out that I needed to make humidity schedule % not fractional, so my error no bug.

@TaylorRoberts, thanks this was a very helpful guide to creating the integrated WSE I was looking to model. I did have to add another set-point manager after my fluid-to-fluid hx in my CHW loop in order for the model to run. Not sure if that was necessary or if I needed it for another reason but thought I would add that.

I would like to know what other's have done for performance curves in OpenStudio. Does someone have a comprehensive library for performance curves for equipment? I have found this document online (Appendix 5.7 Performance Curves), and it looks helpful but I'm not sure how to make sense of it (when I use the performance curves from this spreadsheet I get errors when I run my model). If you don't have a comprehensive list of performance curves, anything would be helpful especially curves for variable speed pumps and fans. Thanks!