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Sustainable design; Energy Evaluation, EcoDesigner and EcoDesigner STAR

Moderators: ejrolon, Barry Kelly, Karl Ottenstein, LaszloNagy, gkmethy

By rod hughes
#149920
Have been using this for about two weeks. Very impressed with speed of computation but would like to know what assumptions are built in to the function settings and also the assumed power and lighting consumptions. Some of the evaluation configurations give wildly inaccurate energy consumption figures when compared to real buildings. I am using this for several small community buildings so building and usage not complicated.

Also wonder whether altering 3d model has any effect upon solar shading given that you enter data on shading in drop down menus, Evaluations dont seem to relate to changes in roof overhangs etc. Anyone have any experience comments? This is a great design tool but be careful of the results.
User avatar
By Karl Ottenstein
#149935
rod hughes wrote:Also wonder whether altering 3d model has any effect upon solar shading given that you enter data on shading in drop down menus, Evaluations dont seem to relate to changes in roof overhangs etc..
No effect - perhaps my biggest disappointment with ED. Adjusting overhangs and playing with different style shading devices is too fundamental (and synergistic) a design issue issue to be ignored in the computation IMHO.

Karl
By cesarzlu
#150777
I am currently modeling an existing single family residence in archiCAD. Our goal is to perform a full energy audit on the residence and compare the existing structure to the structure after energy upgrades are made. We are developing our own energy analysis spreadsheet, and are trying to decide whether eco designer and possibly VIP energy will become a part of our energy auditing procedure. I have been using eco designer for about a week and half now and I am trying to accomplish as accurate an evaluation of the structure as eco designer can allow.

How does ED treat unconditioned spaces such as sun porches and attics? I have a sun porch and I would like to know, if I eliminate it from the building volume do i have to delete it from Archicad? if not does ED recognize there is a porch there that is unconditioned and full of windows?

I also have a partially finished 2nd story that has unconditioned attic space separated from finished space by an insulated wall... I have been able to get the building volume space on the second floor to model correctly but does ED recognize that the "exterior" walls are actually protected by roof?

I have both user guides
(regular and advanced) printed and other information gleaned from forums which I will be using this week as I try to get output from ED that I like for this project. I could use all the help I can get as I continue to learn this program. So if you are listening Karl and Sved, I may need some clarification on this and other questions! thanks
By cesarzlu
#150779
If I change a building elements structure type using the highlight selected element in the model review setting, then re-analyze my model, it reverts back to the original settings and ignores my building structure changes?

How does eco designer decide where to stop the building volume besides story settings? is is just based upon the outer most walls? what about roofs. If you set the story settings for your upper most floor to be above the peak of the roof it would add all your attic space as part of the building volume huh? going back to overhangs/ sunporches etc. can ED recognize such building elements?

on a separate note, what is the naming of materials in the catalog based on? I see timber 500 and timber 700 and wood 500.13 in the cataloge, but I have no idea what that means?

How does ED differentiate between slab on ground and basement floor? can you change the color of basement walls, slabs etc so they view differently in the model review? I feel like I've been working with this program all week and am still in the dark about how some of this stuff works.

also, you should have a tree tool to plop trees in and give them parameters to better model shading. you know, this tree is here and it's about this tall and it's a blue spruce... makes sense to me. and a mesh tool to better model grade change conditions.

why can't you tell ED what layer you want exterior walls on and roofs etc instead of that mark up tool palette model review thing? If ED could recognize building shell elements by layer wouldn't that make more sense? and then you could also split those walls/ roof etc into passive and active in order to differentiate between conditioned and unconditioned space.
By upintheclouds
#150781
"on a separate note, what is the naming of materials in the catalog based on? I see timber 500 and timber 700 and wood 500.13 in the cataloge, but I have no idea what that means?"

Off the top of my head that looks like a specific heat capacity figure, or density.

If you havnt seen this wiki page yet, it could help you with some of your questions:
http://www.archicadwiki.com/EcoDesigner ... tomization

Be careful with these types of numbers for different materaisl as I have found that different sources give different values.
User avatar
By Karl Ottenstein
#150784
Wow. So many questions, that I'm not going to quote them as it will take too long! I do sympathize. Since I downloaded and reviewed the 'advanced' manual that you found here:
http://www.archicadwiki.com/EcoDesigner ... User_Guide

I actually have more questions rather than fewer, myself!

Do NOT click the button to analyze your model after you have made any changes in Model Review (which is almost always necessary)... it takes you back to the beginning, as you saw. Only do that if you have made substantial model changes and it would be faster to reanalyze and change rather than use Model Review to add in or change the modified elements.

The Advanced Guide describes the issue with basement floor vs slab on grade and how to deal with each. However, I was a bit confused in the way that the guide mentioned that the ground level entered in the first screen is used in this calculation... since the ground may well be sloped or stepped. (Early in the guide, it says to use the average grade ... but that's not very accurate for a two-stepped structure on a sloping site where you would want the average for each part. Perhaps in a case like that one needs to analyze each part of the building separately.)

Trees and real shading effects (roof overhangs/etc) are discussed as well ... and that they do not intend for ED to have that level of detail. It does not calculate solarization according to the manual. Thus, the shading values for each facade ... described in more detail in the Advanced Guide (although the numeric value for shading is not quantified in a way to help us know what a sensible number would be were we to want to change things... ditto other numeric values that are basically presented as "here they are" without any units or means to tie them to reality or design intent. I have to assume that the Advanced Guide is a first draft rushed out after I posted the customization article on the Wiki and that it will get edited and fleshed out in time.)

The Advanced Guide also suggests ways of treating unconditioned spaces.

No, you never have to delete anything from ArchiCAD to delete it from the ED building volume. Again, Model Review is your friend ... and essential to understand well. If auto analysis included some structures that should not delineate the building volume, then just select them and clear the highlight. They will then be ignored. Yes, if a wall serves multiple functions, you need to split it in ArchiCAD so that in Model Review you can assign different attributes to it. But, that's how your model should be built anyway.

Unconditioned attic space is described in the Advanced Guide.

Do not know what you mean by 'exterior walls protected by roof'? If you mean that they are shaded, then no. If you mean connected to form a volume, then yes - see Model Review and modify as required with the palette.

I believe that there is a problem with vaulted (cathedral, non-cubic) spaces still and that ED does not compute the volume for them properly.

Back on Model Review... your customization is saved with your file, so it does not need to be repeated. Be sure to say 'yes' to save things.

Telling ED what layers things are on would not really help ... in that ED attempts to intelligently locate enclosed spaces. Some external walls might not enclose a space. No reason to make modeling and layer assignment more persnickety IMHO. If auto-assignment and model review do not quickly describe your exact building volume, then you should post an image so that the ED team can see where there is a problem. Do note! If you have made your model with multiple walls to represent skins (sheathing, finish) etc rather than use a composite, then getting them all assigned as external with proper insulating values becomes a mess... as ED combines the thickness of the wall with the insulative properties to obtain the insulative characteristics of the wall. Also note that it says that ED does not handle complex profiles walls well, which is a shame since I use them for almost all exterior walls and many interior ones.

I do think that Graphisoft would do well to create a tutorial file with a building more complex than the slab-on-grade box in the User Guide and walk us through every step of model review, assignment and analysis, discussing the options and trade-offs along the way. It needs this to be a complete 'product', ready for customer use I think as I think every one of your questions is reasonable and should be answered as part of a methodical case study.

Cheers,
Karl
By cesarzlu
#150834
Karl, I really appreciate the prompt response. I kinda went off on a stream-of-thought question extravaganza there for a minute. After reading all the threads on eco designer and the user guides I have a better understanding of the intention of the program and its capabilities. I hope this discussion is beneficial to others.

I will look back through the advanced user guide as it pertains to my specific questions and hopefully gain some clarity (especially on the unconditioned spaces thing)

I will not use the re-analyze button anymore and instead trust that my changes in model review are automatically reflected in the structures window and stored when eco designer is closed.

I did play around with the ground level input in the first window of eco designer and I now understand how it works in terms of walls and slabs... I
think. re-analyze in model review was doing some weird things yesterday to
my model, but hopefully I can figure out why.

a more intuitive trees/overhang capability not being included in ED is a disappointment as these building and site elements have an important affect on passive solar properties of a building... I'm not sure what ED's assumptions are with the current shading options.

I will un-highlight building elements that I don't want ED to evaluate. I will also continue to use different walls and composite structures to model my buildings accurately.

QUESTION: for the common case of timber framing with insulation between, as far a I know it is not possible to create a composite structure with a material fill to model this scenario (alternating materials in section) in ArchiCAD....

In your opinion, should I:
To ED should I call my framing space by the insulation type in the stud bay, neglect the timber framing and consequent delta-u, and manually change the thermal bridging value in ED to model this condition OR manually input the effective u-value of the wall and leave the thermal bridging value as is...

(I'm trying to avoid having to modify .xml script. I'm hoping that ED has all the thermal values for the materials we will use and that I can interpret the names in the ED library well enough)

speaking of thermal bridge affect, and internal and external heat transfer coefficient... I will have to do some more research to get a better understanding of these inputs as well.
By upintheclouds
#150835
The fact that ED doesn't calculate shading from the model is for me a big let down. Anyone wanting to do any serious "eco design" will be seriously handicapped especially if trying anything involving passive design ideas.

I have the impression that ED is in fact VIP Energy Lite and that in order to do a proper energy analysis one needs to buy a copy of VIP Energy.

As usual with Graphisoft, they don't communicate what their intentions are with ED, so we don't know if it a product that will continue to be developed to include shading, passive house design in the future. This is VERY frustrating!
User avatar
By LaszloNagy
#150843
upintheclouds wrote:The fact that ED doesn't calculate shading from the model is for me a big let down. Anyone wanting to do any serious "eco design" will be seriously handicapped especially if trying anything involving passive design ideas.

I have the impression that ED is in fact VIP Energy Lite and that in order to do a proper energy analysis one needs to buy a copy of VIP Energy.

As usual with Graphisoft, they don't communicate what their intentions are with ED, so we don't know if it a product that will continue to be developed to include shading, passive house design in the future. This is VERY frustrating!
As far as I remember GS has communicated here on this Forum that they intend to further develop EcoDesigner.
But normally software developers do not give promises as to what will be included in future releases.
This is the original thread about ED's release:
http://archicad-talk.graphisoft.com/vie ... hp?t=28266

Here is where I summarize the info I got from GS about ED:
http://archicad-talk.graphisoft.com/vie ... 287#146287
User avatar
By Karl Ottenstein
#150851
cesarzlu wrote:.. should I call my framing space by the insulation type in the stud bay, neglect the timber framing and consequent delta-u, and manually change the thermal bridging value in ED to model this condition OR manually input the effective u-value of the wall and leave the thermal bridging value as is...

(I'm trying to avoid having to modify .xml script. I'm hoping that ED has all the thermal values for the materials we will use and that I can interpret the names in the ED library well enough)

speaking of thermal bridge affect, and internal and external heat transfer coefficient... I will have to do some more research to get a better understanding of these inputs as well.
Since you're in the US, I assume that you mean timber framing (as done with Ralph's / Encina's FrameWright add-on) and not stud framing, which is called timber framing in some other countries.

The Advanced Guide notes that the parameters assume a thermal bridging factor which presumably would account for conventional framing. It does NOT specify what the value of that number in the xml file means in any way to guide us as to how to intelligently modify it.

Were we to have a clear understanding of the thermal bridging coefficient, then that would seem to be the easiest way to handle your walls - customize the xml file (sorry) for the mass of the timbers. Of course, when I say mass - it would only handle the bridging effect. It would NOT handle the actual heat storage mass values of such timbers.

I believe that the only way you might get the bridging and mass of the timbers handled properly is if the timber structure were modeled with columns and beams (or the beautiful FrameWright elements) and the insulation was done as in-fill walls. But, I can't remember if ED will assign thermal properties to columns, beams and objects? (Mind is elsewhere.)

Generally in ArchiCAD "model it the way you would build it" is the rule of thumb to getting good drawings and other data. But, ED lets you make assumptions about the performance of a surface. So, something in between may work ... but it would require that someone from GS or StruSoft explain the thermal bridge coefficient very precisely I think?

Sorry for rambling...can only make guesses.

Cheers,
Karl