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Windows, Energos + U-Values

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Hi All

The energos section of the window tool is asking me to input the R-Value of a window.

We typically specify the U-value of the window which I believe is the norm in the UK.

Is there a way to change the standards that we enter into window objects so that I can enter the U-value and schedule this out in worksheets?

Thanks in advance!

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In the U.S., we also specify the U-factor of a window (U-factor and U-value are interchangeable terms).

R-Value is not typically used as a measurement for glazing products. If Energos is asking for the R-Value of a window, that does not seem correct to me.

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I am fairly confident this will be changed because of multiple instances of this feedback, there are many alterations planned for Energos. I will confirm if possible.

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You can manually override it however:

\Libraries\Defaults\Energy Analysis\EnergyUnits.xml

The Energos can show U-Value or R-Value according to a setting in this file.

false

if you set this value to true it will use U, if you set it to false it will use R

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I am fairly confident it is planned for this toggle to come to the UI, I agree having users poke at XML files is not ideal.

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You can manually override it however:

\Libraries\Defaults\Energy Analysis\EnergyUnits.xml

The Energos can show U-Value or R-Value according to a setting in this file.

false

if you set this value to true it will use U, if you set it to false it will use R

Jim- Will modifying this XML file as you describe set Energos to use either U-Values or R-Values, but not both concurrently depending on the assembly in question?

Currently in the U.S., we specify Wall Assemblies in terms of R-Values (e.g. R-21 Wall Assembly), whereas windows are specified in U-Values.

If we change the XML file to use U-Values, are we now going to have to specify Wall Assemblies in terms of their U-Values?

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It is a global setting at the moment yes, so any place you saw U values would be replaced with R values as well as the reverse.

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Thanks JimW for the clarification. Hopefully, that is something that will be corrected soon. As I already stated, in the U.S. we need to be able to use both U- and R-Values together.

Additionally this seems like something that should not rely on a 'Check Box' setting on the Window OIP. It should be a global Vectorworks Preference that allows you to set via pull-down the correct preset U- and R-Value settings based on your project location.

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I agree with Tim. You already have to enter your project location and the standard you'd like energos to calculate to.

These choices could then automatically affect whether it asks you for the R-value or U-value for windows.

I've also just checked the Passivhaus Planning Package [phpP] and this doesn't ask for the R-value of a window either. As VWs claims Energos is based upon the Passivhaus calculation I'm a bit confused as to why the R-value is the default. Particularly when it doesn't seem to be a US standard either?

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As VWs claims Energos is based upon the Passivhaus calculation I'm a bit confused as to why the R-value is the default. Particularly when it doesn't seem to be a US standard either?

No clue, but submitting all of this feedback for consideration.

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I haven’t tried in Vw2020 yet, but to bump this thread — has the problem reported in this thread (way back in 2016) been addressed?

 

Integrating construction material quantitative reports with Embodied Carbon Calculations will be difficult if we can’t assign the proper respective energy units. Thanks.

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Vectorworks does calculations in field so until in changes you can alway type 1/u-value as R and U are inverse. 

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On 3/6/2020 at 1:22 PM, Matt Overton said:

Vectorworks does calculations in field so until in changes you can alway type 1/u-value as R and U are inverse. 


Thank you for the tip. That’s a good workaround until Vw provides a proper fix (as this would require the user / team to remember in which fields they input a calculated 1/U-value).

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Hi All,

 

On 3/5/2020 at 6:17 PM, rDesign said:

has the problem reported in this thread (way back in 2016) been addressed?

U-Value or R-Value is set as a document unit via File/Document Settings/Units/Energos, with additional option to switch to Imperial, which will display R-Values in sq ft F h/Btu. 

 

On 3/7/2020 at 2:15 PM, line-weight said:

Does anyone actually, successfully use Energos for "real"?

Absolutely, there are a number of companies and individuals using Energos in various workflows - from early stage design evaluation to complex accurate calculations to then be exported to PHPP

6 hours ago, _James said:

UK distributor is running a webinar on Energos this Friday (13th) at 2.30pm

The webinar will cover a number of different Energos features, this is the description:

 

Energy modeling in the early design phase

Climate change and sustainable design is at the forefront of today's conversation. Integrated design tools can help you be more efficient and make quicker decision during the design phases.

During the webinar attendees will learn how to assess the energy performance for a building design very early on in an integrated design process using regular evaluations during the design process. This will give the Architects, the power of being able to make informed design decisions and some metrics to back those decisions up regarding sustainable and energy efficient design. 

 

Learning Objectives: 

Discover the benefits of integrating energy performance evaluation into architectural design workflow

Explore how building's form factor and shape affects it’s energy performance

Learn how various opening shading percentages and different types of shading can guide your design decision based on the expected building performance 

Evaluate energy performance changes based on building elements boundary conditions and U-values

 

Hope this helps!

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Posted (edited)

@Luka Stefanovic Thanks for the reply.
 

I guess the original thread topic still stands as ideally different building components are typically specified as U-value or R-Value, not as a global setting for all values. As noted, windows are typically specified in terms of their U-value, whereas wall assemblies are typically specified in terms of assembly R-value. We need to be able to specify both.

Will this Energos webinar be recorded and made available for viewing by non-UK VSS subscribers? As there are currently no Energos workflow training webinars available on either the U.S. VSS portal or Vw University, having access to this UK-focused one would be much appreciated. Thanks.

Edited by rDesign
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On 1/29/2016 at 8:10 AM, PVA - Jim said:

I am fairly confident this will be changed because of multiple instances of this feedback, there are many alterations planned for Energos. I will confirm if possible.


@Luka Stefanovic here’s a post from Jim W. back in 2016 acknowledging the need to specify in terms of both U- and R-values.

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@rDesign I'm not aware of a setting which allows you to display both U-values and R-values simultaneously, but I'm UK based and only ever used U-values really so the option works fine for me. I might be missing a trick here but I will check with our team in the US and report back. As someone in the thread mentioned, the relationship between them is inversely proportional, so if your Units are set to R-values you could have a small window U-value conversion worksheet to display 1/R-value. I understand it's a workaround but I'll let you know if it's possible to do it on an object by object basis.

 

1 hour ago, rDesign said:

As there are currently no Energos workflow training webinars available on either the U.S. VSS portal or Vw University, having access to this UK-focused one would be much appreciated

We are doing a webinar for our US customers in May, it will be announced soon. I'll post a link to register in this thread when we have a date. @Luc Lefebvre what's your view on this?

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