Environmental Design

Re: Environmental Design

fostertom — Wed, 17 Dec 2008 15:34:45 GMT

I revise my previous mentions of FEA in dynamic thermal modelers. Here is an excellent summary: http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1427&page=4#Item_3 - see BristolPaul's post, incl

"TAS has an hourly simulation timestep. Heat transfer through the fabric of the building is dealt with by a response factor approach (ASHRAE methodology) and the overall heat balance is gained by basically solving a set of simultaneous energy equations for the surface and air temperatures, etc at the same time."

This, and other dynamic modelers' methodologies, is not FEA but is still 'superior' to the approach of the 'second rank' of modelers such as (AFAIK) Autodesk's EcoTech and the free Canadian Hot2000 (not to be confused with Hot3000).

Re: Environmental Design

fostertom — Thu, 30 Oct 2008 02:19:06 GMT

Thermal modelling goes mainstream: http://www.aecmag.com/index.php?option=com_content&task=view&id=257

A somewhat cut down FREE version of EIS is now available not only for Revit, but now Sketchup Free!

Every 'design your dream house' amateur will now be getting hands-on experience of fundamental and detailed energy efficiency factors, and as such may well find themselves better informed than any professionals they may turn to.

Brilliant

This must mean that model simplification happens automatically - no way would a Sketchup Free app require the model to be rebuilt just for thermal modelling?

Re: Environmental Design

fostertom — Wed, 22 Oct 2008 20:51:23 GMT

All true, so Autodesk/EIS/Ecotech boasting about so-called direct import from CAD (actually via shaky gbxml) is a red herring - so far.

But if in future CAD models can be imported and automatically simplified as necessary for Tas etc, why not?

Would be specially useful when trying different building shapes - instead of changing the model manually many times iteratively and re-running Tas, to find optimum shape for thermal performance, great to do the changes in a parametric CAD modeller and re-import.

Even better to let GC do the iterations for you, to converge on thermal optimum.

Re: Environmental Design

Andreas Zieritz — Wed, 22 Oct 2008 17:51:12 GMT

I'm just back from a weeks training course in TAS, and would like to share my points of view.

To come with the conclusion first - it doesn't make any sense to put every information in one model. There are far too many different interests between the different professions. While an integrated approach between the architect and the structural engineer sometimes makes sense, it's a different kind of thing between the environmental stuff and other professions.

When designing 3D models in TAS, you don't snap to anything at all. +- 50mm, even 100mm doesn't change anything at all. You really just sketchup the model, like you would do by hand.

The thing which is much more interesting in TAS is how your wall is built up, which layers it has, and how they perform (humidity, insulation, thermal mass). More or less things which I'm not interested in as a structural engineer at all.

Others things are e.g if you can open your windows, if you have blinds (permanently or when the sun is shining), how your ventilation systems performs, etc.

It's really 2 completely different subjects. So it doesn't make any sense to make one model. Usually you don't have the time to do that eather...

Re: Environmental Design

fostertom — Wed, 22 Oct 2008 14:46:43 GMT

Stunning simulations of what Ecotect can do, standalone or allied to Autodesk products: http://www.nottingham.ac.uk/sbe/creative_energy_homes/stoneguardC60/analysis_animate.html - and Ecotect isn't even a true dynamic FEA modeller like Bentley (EDSL) Tas http://www.bentley.com/en-US/Products/Bentley+Tas/ or Bentley Hevacomp simulator http://www.bentley.com/en-US/Products/Hevacomp+Dynamic+Simulation/

I'm looking forward to this and more, seamlessly in Bentley products, and hope it happens soon enough to catch this wave, which has already been going strong for a year

Edit: see my post 17 Dec 08 - it's not FEA

Re: Environmental Design

fostertom — Sun, 12 Oct 2008 23:46:14 GMT

Thomas V, that's a good article from 'few years ago' . But Danny, is that what you meant? Seems Thomas is talking about embodied energy of building components, which can be simply totalled.

If you're talking about energy in use, that surely can't be assessed that way. Yes the physics attributes of individual components, as well as their geometry (shape and relative position) can be very neatly input as part of a BIM model, rather than manually addfing the physics attributes to the geometry within Tas or whatever. But the physics result (thermal behaviour) depends on the interplay between them and weather changes, sun path etc, which no BIM is capable of - yet.

A FEA program like Tas recalculates the way that heat is passed from one component (or part of a composite component) to another, time and again, iteratively, in small time steps. We have to look forward to Tas's capabilities being added to Microstation or BA.

What's interesting beyond that, is the possibility of those physics attributes and the Tas capability becoming something that GC could handle, with non-geometric parameters (the physics attributes, weather changes, sun path etc) allowed to play just like geometric ones, governed by rules (Tas's algoriths, you might call it) to automatically generate thermally optimised buildings. I'm sure that fantastic possibility is what Bentley sees in Tas, and with Hevacomp they have access to another thermal modeller as well.

Presumably at heart GC is already a kind of FEA program, if it recalculates time and again in small steps. The time dimension (Thomas's 4d) is already here!

There's discussion about this on the Green Building Forum http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1427&page=3#Item_21

Edit: see my post 17 Dec 08 - it's not FEA

Re: Environmental Design

Thomas Voghera — Fri, 10 Oct 2008 15:16:32 GMT

I agree and think the same.

http://discussion.bentley.com/cgi-bin/dnewsweb.exe?cmd=article&group=bentley.triforma.structural&item=2754&utag=

is how I wrote about it s few years ago. Keeping as much as possible "in" ustn.

Triforma parts, or probably better DGS. The Components still has a def for "lambda". Has anyone ever used it in ustn? Or in Brics?

--
regards /Thomas Voghera

<danny-cooley> wrote in message news:16303@communities.bentley.com...

Hello Tom

Must admit "full" FEA is beyond myself at this point. I was tying to think along the lines of something that would allow me (or someone) to compile or "catalogue" various "eco-points" (depending on which environmental performance system they're using) as they are building up their model(s). I'm still more inclined to attemp this by building up a (Triforma) dataset, that includes various environmental performance factors/weightings than exporting the model(s) to various other apps for further analysis.

The idea being that in the same manner that you can extract a door schedule, areas schedule or various quantities (tons of concrete or whatever), you could then "scan" the model(s) and it would total up your score: ....... you have achieved 87 points which is the equivalent to BREEAM very good or Code for Sustainable Homes Level, 3, 4 or 5 (for example). I assume this would/could be output to a spreadsheet (or maye something more customised to your requirements) so that you could review the overall performance and see where you might be able to improve things or how to go about "trading off" various aspects of the design.

Must admit, I've only really started "playing" around with this (there's still stacks of other goodies to do things with!) so won't be able to provide any real results/feedback for some time (like next year at this rate ...... )

------------

Apparently now, Bentley own TAS ...........

http://www.bentley.com/en-US/Products/Bentley+Tas/

Seems to have slipped by quite quietly that one

This would seem like good news (for Microstation users particularly)

Looking forward to seeing what they come up with

Regards

Danny Cooley

Freelance CAD technician

http://communities.bentley.com/Products/Building/Building_Analysis___Design/f/5917/t/8684.aspx#16303

Re: Environmental Design

danny-cooley — Fri, 10 Oct 2008 05:34:34 GMT

Hello Tom

Must admit "full" FEA is beyond myself at this point. I was tying to think along the lines of something that would allow me (or someone) to compile or "catalogue" various "eco-points" (depending on which environmental performance system they're using) as they are building up their model(s). I'm still more inclined to attemp this by building up a (Triforma) dataset, that includes various environmental performance factors/weightings than exporting the model(s) to various other apps for further analysis.

The idea being that in the same manner that you can extract a door schedule, areas schedule or various quantities (tons of concrete or whatever), you could then "scan" the model(s) and it would total up your score: ...... you have achieved 87 points which is the equivalent to BREEAM very good or Code for Sustainable Homes Level, 3, 4 or 5 (for example). I assume this would/could be output to a spreadsheet (or maye something more customised to your requirements) so that you could review the overall performance and see where you might be able to improve things or how to go about "trading off" various aspects of the design.

Must admit, I've only really started "playing" around with this (there's still stacks of other goodies to do things with!) so won't be able to provide any real results/feedback for some time (like next year at this rate ..... )

------------

Apparently now, Bentley own TAS ...........

http://www.bentley.com/en-US/Products/Bentley+Tas/

Seems to have slipped by quite quietly that one

This would seem like good news (for Microstation users particularly)

Looking forward to seeing what they come up with

Regards

Danny Cooley

Freelance CAD technician

Re: Environmental Design

fostertom — Thu, 09 Oct 2008 04:44:11 GMT

AFAIK Ecotect isn't a FEA program - not a dynamic modeller which recalculates the whole again and again in small time steps. If not FEA, so-called thermal modellers are just basically spreadsheets that have been tweaked empirically to come close to the results of a proper FEA simulation - however good their front end looks. Unless FEA, they are only accurate within pre-conceived and verified limits, whereas a true FEA program is more 'do-anything' from first principles.True FEA modellers are Tas (UK), esp-r, (UK) Hot3000 (Canadian using esp-r as engine) and EIS (UK). Not sure about Hevacomp's, which is based on a US program, reputedly very slow

Edit: see my post 17 Dec 08 - it's not FEA

Re: Environmental Design

danny-cooley — Tue, 16 Sep 2008 04:56:24 GMT

Hello ...

I must admit these are things I've heard of and am vaguely aware of (but only vaguely)

I had a browse around the Hevacomp web site and it would seem to be a very good move by Bentley. Though probably a fair bit too advance for myself, and I'd guess many people mainly working as architects (more for the M & E people I'd guess)

Tas looks very promising and I’ve heard good reports about it. Though again, probably a bit too advanced for myself at this stage.

Andreas: I'm glad you've had some good results/are pleased with the TAS products

"it shouldn't be any problem to use programs from different software companies" I wish I shared you're optimism on that one!

I might give it a go at some point. For the time being I guess I'll attempt some tweaking in Triforma/BA. Though that would seem like a long haul.

Most of the products/solutions available seem to mainly focus on HVAC related issues. Perhaps understandable as they were probably initially developed with that in mind. And no doubt the big issue of the moment

What about recycled content? Toxicity? Water re-use/recycling? Flexibility? Potential for disassembling/re-using parts of the building, or building component.

It would seem there is a reasonably clear path for assessing if your building (or proposal) complies with the various structural codes (give it to a structural engineer huh!), if it complies with various energy related issues/requirements (guess who you call then? those nice people who work in M&E). This can be done suffciently/adequately/impressively (take you're pick) with Bentley's current suite of products.

It would seem at the moment then the main thing to do with respect to environmental impact assessment would be to export your model to another package. But this will still entail some further re-modeling it would seem. I can accept that to some degree, as regardless of the package, I assume at some point you will have to "tell" it what you want to assess and where

From what bits I've seen (only playing around with the trial version briefly and then seeing a demo), for my more immediate purposes (and I would have though for architectural practices generally), Ecotect seem to be a few steps ahead of the other options. I was quite hopeful that there would be some more dynamic linking with dgn stuff in the pipeline. Though as this is now an Autodesk product, maybe they aren't in too much of a rush to develop things too much in that direction. Maybe the recent dgn/dwg agreement will prove to be fruitful. It may still be someway off before we see any significant benefits from that (next year?). As mentioned, I think I'll prod around with BA for the foreseeable future (some months probably) and see how that pans out before I attempt anything with any other products.

Anyway, …..

Thanks again

Regards

Danny Cooley

Freelance CAD technician

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Re: Environmental Design

Andreas Zieritz — Mon, 15 Sep 2008 15:06:24 GMT

EDSL TAS is actually a superb product which we are using here in our office. What I like is that they want to be independent of the big software companies. For me it's more important that a product is good, than that it is integrated into something else we already have in our office. As long as all programs support open interfaces (gbXML, IFC), it shouldn't be any problem to use programs from different software companies.

Re: Environmental Design

fostertom — Sun, 14 Sep 2008 01:38:52 GMT

First http://www.bentley.com/en-US/Corporate/News/Quarter+1/Hevacomp.htm?skid=CEE_NA_COR_BN_76_080130&MIG=http:

Then http://www.reuters.com/article/pressRelease/idUS149469+30-Jun-2008+BW20080630

EDSL Tas is the second best of all the dynamic (FEA) thermal modellers - the others have also been bought up by CAD majors, except the acknowledged best, esp-R, which is still not married off. Hevacomp is useful too. Bentley have taken the crown jewels, this time. I await integration of these non-geometric parametrics into GC, with great interest

Edit: see my post 17 Dec 08 - it's not FEA

Re: Environmental Design

Mueller — Sun, 14 Sep 2008 00:46:25 GMT

In addition to the GC to Ecotect connector Bentley Architecture does have gbXML export in beta now. Here is a link to the Bentley Architecture list of features.

Re: Environmental Design

Ben Doherty — Sat, 13 Sep 2008 09:29:12 GMT

There is a very embrionic GC--> ecotect live interface. this still has some potential to be useful, but even if it never really goes anywhere, i'd still go with ecotect as my analysis package of choice.

unless you get a rash if you go near the big A, in which case, topical cream should solve it.