Anna Osborne Brannon's profile - activity

I am working on a CBECC-Com 2013-3e model review. Exterior shading surfaces were created by right-clicking on a zone, and selecting "create" -> "external shading object". The shades then show up as blue icons beneath that zone:

The odd thing is that I noticed that when I move these shades to a different space- the actual spaces they are shading- the results of the simulation changed. This seems odd to me since these are coordinate-based shading surfaces, so theoretically it shouldn't matter where they are in the model.

Next I also tried adding shades on the windows themselves using the "define window shades" option:

This also yielded very different results. Though when I look into OpenStudio or the .idf file, both of the above options for creating shades is creating a "shading:zone:detailed" object. I thought maybe the first option above was using a "shading:site" or "shading:building" object.

Has anyone seen this before or does anyone have theories or ideas for the discrepancies?

Importing WINDOW 7.5 Data to eQuest 7175 After importing a WINDOW 7.5 file into eQuest 7175 (using DOE 2.3) and running

I want to quickly output zone-by-zone heating and cooling loads in the HVACSizingSummaryoutput report. The simplest approach I know is to use an HVACTemplate:Zone:IdealLoadsAirSystemobject. Though I can't seem to get my model to output the Zone:Sizing object like the other templates. For example when I replace the ideal loads air system and useHVACTemplate:Zone:VAVon the same exact model Zone:Sizing is created as it should.

I do have "do zone sizing calculation" selected in SimulationControl, and when I manually add Zone:Sizing, my simulation runs and the HVACSizingSummaryoutput report is populated. I just want to understand why the template isn't doing this like it should.

Here is a snapshot of my idf:

and the expanded idf (no zone:sizing object):

I can see that the zone:sizing object should show up in the expanded idf, as it does in the example file HVACTemplate-5ZonePurcAir, but it does not in my file.

@mikesweeney - It appears the link is broken to your Github repository. Do you still have this python script to share, w

EnergyPlus vs E+ GUI: Which to Choose I'd like to create a reference documenting the benefits and drawbacks of using Ene

EnergyPlus vs E+ GUI: Which to Choose I'd like to create a reference documenting the benefits and drawbacks of using Ene

Can you post an image of the error you are getting? And confirm what version of IES-VE you are using, and what version o

I am modeling a UFAD system in IES-VE. IES has the capability of modeling several zones, so I have followed the ApacheHVAC Manual Appendix G: UFAD Systems guidance to have a common supply air plenum, a 6' high occupied zone, a stratified zone, and a common return air plenum. The guide also recommends using a 55F coil SAT, but modeling heat gain through the supply plenum by raising the temperature of air coming from the diffusers. My question has a few parts: 1) is this zoning method the best practice 2) is accounting for heat gain through the plenum necessary and 3) do most UFAD systems use 55F SAT at the coil or an elevated SAT at the coil? Any suggestions of the best approach for splitting up the zone and the supply air temperature setpoints would be appreciated, or references that outline the approach.

Can you add this as a comment to my answer, instead of another answer?

How do you model the external adjacency for a ground-contact slab? This site recommends using ground temperatures of 2C below average internal temperatures (for large commercial buildings) and to not include ground material. Is this the recommended approach, and is it a constant temperature profile? What about for small or mid-size commercial buildings?

HVAC Templates to be Discontinued? I just saw in a few notes from a talk at BS 2017 that there are no plans to bring the

@UilissonGFM, you can do all of the loads, HVAC, and lighting systems in OpenStudio. The only exception is if you have s

It sounds like you don't have very clean geometry. Where does your geometry come from? Is it an architect's model? If yo

It sounds like you don't have very clean geometry. Where does your geometry come from? Is it an architect's model? If yo

It sounds like you don't have very clean geometry. If your geometry isn't well enclosed and built to be an analytical mo

The answer is you can use either. They both have their own advantages. OpenStudio is an Object-Oriented Application Pr

Thanks, I hadn't noticed this. The client still requested option #3, based on their experience with measured data. Ideal

How do you account for distribution losses when modelling a central plant?

Some resources (like the LEED DES guidance) say to use 2%, or 5% losses, but don't exactly elaborate on how those losses are applied. I've heard of modelers using a few methods which yield very different results:

1. Decrease the efficiency of the plant by the loss, so if its 2% losses, decrease the plant efficiency by 2%. This basically results in a 2% increase in energy use.

2. Decrease the annual chilled water output by 2%, then re-calculated average efficiency for application to your model, if you have a separate central plant and building model. This also results in close to 2% increase in energy use.

3. Apply the losses as a constant percentage of the total plant capacity. If you have 1000 kW of plant capacity, that means a constant 20 kW of losses at every hour of the simulation. This causes a significant increase in energy use, in excess of 10% increase.

Does anyone have guidance that shows which of these methods actually most closely represents measured data?

Thanks, I hadn't noticed this. The client still requested option #3, based on their experience with measured data.

Representing Distribution Losses How do you account for distribution losses when modelling a central plant? Some resour

Thanks, I hadn't noticed this! The client still requested option #3, based on their experience with measured data.

Representing Distribution Losses How do you account for distribution losses when modelling a central plant? Some resour

Representing Distribution Losses How do you account for distribution losses when modelling a central plant? Some resour

What are your favorite ways to create geometry for use in EnergyPlus natively and what are the pros and cons for each? Options that I can think of are:

1. Euclid plugin for Sketchup - slower to use since zones must be created individually
2. OpenStudio plugin for Sketchup - "create spaces from diagram" allows floor places to be built up quickly
3. Design Builder - if you already have a license

I have heard that Euclid creates cleaner geometry and is less error prone than the OS/Sketchup plugin. Can anyone confirm if they have had this experience?

To clarify- I am not asking about the difference between using OpenStudio as an API for EnergyPlus or using EnergyPlus directly. I'm only curious about geometry creation.

EIRfPLR vs EIRfPLR&dT For the chiller electric input ratio as a function of part load ratio chiller curve, IES-VE an

EIRfPLR vs EIRfPLR&dT For the chiller electric input ratio as a function of part load ratio chiller curve, IES-VE an

@Julien Marrec, I've added more detail to my question to better explain what I am looking for. I'm specifically interest

EIRfPLR vs EIRfPLR&dT For the chiller electric input ratio as a function of part load ratio chiller curve, IES-VE an