The World is my Oyster...Again!

Experienced Architect and Design Technology Consultant very excited about the opportunities that are awaiting me in this great wide world. For more about me, check out my LinkedIn profile. I am open to any and all possibilities. Whoa...Déjà vu!

New Worlds

Just so I have at least one more post this year…I thought I would throw this up.

New job, in a new city, with a new house, new schools, new people.  At least the earth is remaining the same…except for that whole global warming thing. 

Where to Next

I don’t know.  The reasons for wanting to blog haven’t changed.  I will hopefully journal about technology, architecture, sustainability, business, wine, chocolate, LEED, Revit, fashion, design, and food.

But we will see.

One thing I have done recently was talk about technology implementation.  Check it out here:  http://aiacc.org/now-next-future-conference-presentations/

I had the honor of sharing the stage with some very esteemed speakers.  It was a humbling and invigorating experience.

The World is My Oyster

Experienced Architect and Design Technology Consultant very excited about the opportunities that are awaiting me in this great wide world.  For more about me, check out my LinkedIn profile.  I am open to any and all possibilities.

Vasari 2.0 Just Released

Check out the new features here.  Also check out their project page here.  Note that this version is based on Revit 2012.  Also note that it does not expire until December 31, 2011.  Super cool stuff!!

Function Matters for Shading

Now, I’ve been using Revit for a long time.  And just when I think I know a thing or two about it, I get slapped in the face with something new.  Maybe this has been around for a while, I don’t know.  But recently, I have been digging deeper into gbXML exporting and workflows between Revit and energy analysis tools, and today I discovered a tasty little tidbit that was most interesting, if not a little confusing.  So for your reading pleasure, I offer you the following.

Function

There are a number of system families in Revit that have a Type Parameter called “Function.”  For years, I ignored this little setting.  Superstitiously, I would modify it when I made new wall types, but I didn’t really know what would happen if I didn’t.  Well now I do…at least a little.

I was digging deeper into the meaning of Sliver Tolerance and it’s affect on the gbXML file and subsequent Ecotect model.  I had made an interior shaft and was studying it. (I know what you’re thinking, “Wow, I wish I had his life. It’s so exciting!!).

When I looked at the analytical surfaces, I saw what I expected to see.

Then, I haphazardly swapped out a standard interior partition for an exterior brick wall.  I expected to see the same image again.  Well, wouldn’t ya know, the next time I looked at the analytical surfaces in my gbXML preview window, I saw a little piece of something poking up.

I completed the export process and dropped the gbXML file into Ecotect.  Sure enough, that little surface, even though it is under the roof, was assigned to the External Shading zone.

Experimentation

So now I start down the rabbit hole. 

First, I put a room in the attic space.  As soon as a room object was touching the wall, it turned into an Exterior Wall surface.  In addition, all of the interior partitions stopped being ignored.  They showed up as  Interior Wall surfaces, now that a room was touching them.  (I should note at this point that all walls in this little building extend up and are attached to the roof).  This was the behavior I expected, so before continuing on, I deleted the room.

Next, I started changing the Function parameter to the various options and viewing the results in the Export gbXML dialog.  The values of Exterior, Foundation, Retaining Wall and Soffit, all acted the same.  Interior and Core-Shaft did not, they were ignored.

I was half way down the rabbit hole at this point, so I decided to continue to see what I could find.

Shading Surfaces

I know now that walls, whose Function is set to Exterior, Foundation, Retaining and Soffit, all produce Shading Surfaces when they are set as Room Bounding and not adjacent to any rooms. 

In addition to walls, floors also have the Function parameter.  The values are limited to just Interior or Exterior.  If a floor’s Function is set to Exterior, if it is room bounding, and if it is not adjacent to any rooms then it will be exported as a shading surface.

Note that you must have your Export Complexity set in the Export gbXML dialog to “Complex with Mullions and Shading Surfaces” to get all of these to show up.  Depending on the size of your model, this may result in a slow export.

No Function

There are some other objects that do not have the Function parameter but still create shading surfaces in the gbXML.  These are Roofs and Curtain Wall Mullions. Roofs make sense.  Curtain Wall Mullions make sense.  But what about mullions in regular window families?

I tried to add an object in a window family to act as a light shelf spanning from interior to exterior.  I set the subcategory to Frame/Mullion.  Sadly, I discovered that gbXML does not recognize that subcategory as a shading surface like it does the curtain wall mullions.

So apparently, you must create your light shelves in Revit out of floors or roofs (or ceilings on the inside).  However, beware that as soon as you project a room bounding object into a space, you get all sorts of craziness…

like voids and exterior walls disappearing.  Notice that there is no Exterior Wall surface above where the roof cuts into the inside of the building.

At this point, I don’t have any good suggestions on how to do light shelves.  If someone out there does, please comment below.

In Conclusion

I found the bottom of the rabbit hole!  I can’t go any further right now.  However, along the way, I figured out some cool new stuff that can improve the quality of my gbXML exports.  It was good exercise crawling down that rabbit hole.  Sadly, I didn’t see any cute fuzzy bunnies or that waskely wabbit. (Elmer Fudd)

Ironically, when I bottomed out, I started looking in the help menu and found this on the new WikiHelp that Autodesk is doing now for 2012 products.  I also found this helpful, although I don’t think it is quite accurate.  In any case, I hope this has been useful.  Stay tuned for more coming soon.

Conceptual Energy Analysis in Revit (8 of 8)

Well, this is it.  The cone of silence is coming off.  Now, my mother always said, if you can’t say something nice, then don’t say anything at all.  In addition, I have always felt that “the truth” is no excuse for hurting someone’s feelings.  So with those two things in mind, I will make the following entry.

It has been a number of months since my last post.  In that time I have been learnin’ me some stuff.  I have been learnin’ that there are some super smart people in my company that know a whole lot about energy modeling and energy analysis.  I have also learnt that there are standards, protocols and procedures that are industry wide in the area of energy modeling.  So with my newly found learnin’, I have a couple comments on the Revit Conceptual Analysis tool.

Zones

First, let’s talk about zones.  The automatic zoning does not follow standards.  I am not going to quote chapter and verse of where the discrepancies are, but I do know that this is right..

and this is not right.

The automatic perimeter zones do not stay at the corners of the geometry as is dictated by industry practices.

Other Stuff

There are some other issues that need to be addressed before this is going to be a good automated tool.  I don’t really feel like listing them all.  Suffice to say that before embarking on any preliminary energy analysis using the CEA tool, be sure you are aware of the energy modeling industry standards for modeling and setting up zones.  Some good references are ANSI/ASHRAE/IESNA Standard 90.1-2007 (I-P Edition) Page 179 and Commercial Buildings Energy Modeling Guidelines and Procedures, RESNET Publication 2010-001.  This is not all inclusive, but it is a good place to start.

In Conclusion

This has been a fun series.  I have learned me a ton of stuff…my head hurts ‘cause it’s so full.  I think I will continue to write on Revit CEA, now that 2012 is out.  I will probably write some on Ecotect, Green Building Studio and gbXML. 

Also, I will be attending the AIA Convention in a couple weeks in New Orleans.  I am planning to blog about all of the classes and events I will be attending.  Lots of stuff about AIA TAP and BIM and sustainability.  So come back and check me out soon. 

Conceptual Energy Analysis inside Revit (7 of ?)

As I sit here listening to Let it Snow on my IPod and enjoying a peppermint candy cane chunk, my mind wanders…what is in that really big present under the tree with my name on it…elves pointy ears must never get cold since they are never tucked into their pointy hats…how do I customize the properties of surfaces and zones in Revit CEA?  Weird?  I don’t think so.  It’s Christmas…why shouldn’t I be thinking about elves?  Merry Christmas!

In the last post, we talked about how to customize the zones and glazing on our mass model using geometry.  There was a lot to cover and by the time we got to the end, we had all run out of steam.  So we didn’t talk about the other way to customize, by adjusting the analysis properties of individual surfaces and zones.  So let’s get into it now.

First things to know is that to adjust surfaces or zones you need to have the appropriate Show Mass option selected.

Surfaces

There are a lot of new kinds of sub-categories courtesy of the CEA tool.  You can see them by expanding the Mass category in the Object Styles.  All but one of them are related to surfaces.  You get just one guess as to which one is not related.

To access the surfaces of your model, you need to switch your view to Show Mass Surface Types.  Once you get your model showing surfaces, the Tab key on your keyboard will be your buddy.  Use it to toggle through the different surfaces.  Now find and pick on Mass Exterior Wall and check out what is available in the properties palette. 

To access the customizable fields you will need to change the Values parameter from By Energy Settings to By Surface.  Now you can adjust the glazing and shading.  You can also change the Conceptual Constructions which allows you to affect things like the R-value, unit density and heat capacity.

Now tab to pick a window on your surface.  Oh, huh.  Weird.  All the windows on the surface are picked.  So now you can change the Conceptual Constructions for the glazing types for a surface.  But you can’t change it per window.  I hope that will be fixed in the future.

If you keep moving around and tabbing you can find the other surfaces like Mass Roof, Mass Interior Wall and Mass Floor, each of which will allow you to change various settings.  This is how you customize your surfaces.

And finally, on surfaces, if you happen to figure out how to make a Mass Opening, please let me know.  I have tried a bunch of different ways to see if I can generate a Mass Opening but with no luck.

Zones

Just like with surfaces, to be able to customize your zones, you need to be sure you can see and select them.  To do this, change to Show Mass Zones and Shades.  Now I don’t know why it says Shades.  I can see the Shades (as in window shade projections) in both the Show Mass Surface Types and Show Mass Zones and Shades.  Maybe the word Shades should be removed.  Or maybe I am just splitting hairs or candy canes.

Now that I can see my zones, I can pick one and check out what is customizable in the Properties palette.  Not as much as for the surfaces, but you can change the space type.  This allows you to customize your zones to have different energy use values than the default building type set in the Energy Settings dialog.  To see what values change, check out the Reference for Conceptual Energy Analysis under Space Type Data.  There you will find 125 different space types and associated energy use data.

One last thing on the zone properties.  In case you haven't been following this series, you should not try to change the Graphical Appearance of a zone.  Or at least if you do, don’t try to change it back to By Surface Type.  For more info see my earlier post here.

Well that’s all I have discovered regarding customizing your energy model.  I hope you have been able to glean something.  And if you have something to share back, I would love to hear it.  I am all about the rigorous exchange of ideas.

And if I don’t write again in the next couple weeks, some seasonal wishes for you.  May you get everything you want for Christmas, except for one thing so you can have something to wish for next Christmas.  May you eat enough Christmas dinner but not so much your shirt and pants pop open (this isn’t Thanksgiving ya know!). 

And finally, may you find someone less fortunate than you and help them out, so you can get that true Christmas feeling in your heart.  Food, clothes, shelter, shoulder.  If you have it and they don’t, share!

Merry Christmas and Happy New Year.

Conceptual Energy Analysis inside Revit (6 of ?)

Everyone likes the word ‘custom’.  It is on of those words that has increased the value of countless, otherwise mundane items.  It makes the item feel special, unique and individually tailored.  And anyone can us it.   See what happens when it is added to everyday words.  Custom Shoes, Custom Car, Custom Paper, Custom Design (one of architect’s favorites).  But does it work in Revit.  Do you get the same feeling when you read:  Custom Energy Model?  Yeah, me neither.  So we don’t feel the same about a Custom Energy Model as we might a custom suit, but let’s try it on and see how it fits (see what I did there).

Customizing the Energy Model

There are three basic ways to customize your energy model in Revit.  The first way is through geometry by creating custom zones and fenestration.  The second way is through the analysis properties of individual surfaces and zones.  Finally, the third way is to adjust the graphical appearance of each individual zone or surface.  Although this last one sounds good in theory, it does not work well.  You can check out my previous post “Hey Doc, it hurts when I do this…”.  In addition to this issue, I discovered that if you change the graphical appearance of an analytical surface to anything other than By Construction, you cannot get the graphical appearance back to By Construction.  Oh sure, it says in the parameter value “By Construction” but the actual graphical appearance in the modeling window is still whatever the last material was.  I have another support request into Autodesk for this.

Geometry for Custom Zones

But let’s re-focus and talk about what does work.  It is actually quite cool to be able to use the auto-magical zone tool.  In talking to a few engineers and energy modelers, the zoning that is produced by the CEA tool is much more realistic than what is required for a Revit gbXML export.  Five zones per level is more like what the engineers want to work with, instead of a zone for every room in the building.  But sometimes the way the zones work out is funky, so sometimes it is better to create your zones more deliberately.  It is really quite simple.  You just need to think about creating a mass for each zone you want.  The best way to do this is to create your overall mass building shape.  Then for every place you want a zone, you create another mass and subtract it from the overall mass using the Solid-Cut-Solid tool.

 

Once you finish your mass, go to the Energy Settings and check the Create Energy Model checkbox.  Be sure to set your Core Offset to 0’ and uncheck Divide Perimeter Zones.  Now click OK and check out the zones in your model.  You will have one zone per mass per floor that the mass intersects.  You can see this by selecting various zones and using Hide/Isolate to expose them as shown below.

Talking to your energy modelers or engineers when doing this will really go a long ways towards getting a better model for analysis that they will not have to fiddle with as much.

Geometry for Custom Fenestration

The next major way to affect your energy model through geometry is by doing custom glazing.  It is really nice to use the Target Percentage Glazing parameter in the Energy Settings dialog to set your glazing automatically for you.  And I think that at the conceptual stage this is probably the best thing to do, but you can make your own glazing layout using some new drawing features in the Conceptual Massing environment.

These new options appear when editing a mass in the options bar when you start the draw command (either line or rectangle) and check 3D Snapping (as shown).  They allow you to draw on the surface of your mass.  Now, in order for the CEA to know that these are windows you’re drawing and not just lines on the surface of your mass, you must have “Make surface from closed loops” and “Sketch on Surface” checked.  So, what do these three options do?  David Light has a very good blog entry on their function here.  But suffice to say they allow you to draw glazing on the surface of your mass.  Like so (showing mass surfaces)…

As you play around with this you will get the feel for it.  It can be very useful.  But it can also be a little frustrating to try to draw something regular on an irregular surface.  But give it a try.

It is important to point out that you can combine the custom glazing with the Target Percentage Glazing parameter.  However the results are very weird.

This is what it looks like when I go into the Energy Settings dialog and set the Target Percentage Glazing to 50%.  The little windows that run up the sides of the large custom glazing areas are what Revit added.  As you can obviously see, the glazed area is far more than 50% of the wall area as set in the target parameter.  What this means is that Revit does not take into account the custom glazing in the target percentage calculation.  In fact, it is very difficult to see how the math is being done.  So when using both % glazing and custom glazing, Revit sees the custom glazing shape and adjusts the automatic glazing around it but does not take the custom glazing into account when looking at the target percentage glazing.  Target percentage glazing is only calculated by the automatic glazing feature.

Wow!  So that was a lot longer than I thought it would be.  I will pick up with the other way to customize - through the adjusting of analysis properties of individual surfaces and zones – with the next post.  For now, I will leave you with one of my all time favorite quotes.  I don’t know who said it but for sure they were smarter than me.

“Heavy emphasis on the “how-to” guarantees the loss of the critical “why”.

Hey Doc, it hurts when I do this…

 

It always hurts when Revit crashes on you.  It’s a little like a good friend letting you down.  They didn’t really betray you, but they took the last cold beer and didn’t put more in the fridge and so you are just a bit disappointed and a little hurt. 

This is what I am feeling today.  Both Revit Conceptual Energy Analysis tool and the brand new Vasari (and on Facebook) technology preview, seem to have the same unfortunate flaw.  Now maybe it is just my computer.  Maybe someone can tell me.  Try this and tell me if you get the same results.

Make your conceptual mass, assign floors, geographic location, check the Create Energy Model check box and click OK.  Next, in a 3D view, switch to Show Mass Zones and Shades.  Now, pick one of the zones and in the Properties Palette, click on the nugget for Graphical Appearance.

In the Materials dialog box, choose By Category.  Now choose that same zone, click the nugget again and change it back to By Surface Type.  If your Revit is acting like mine you will get this.

I have tried this with various templates in both Revit Architecture and Revit MEP with the same results.  I was playing around with Vasari and on a hunch, tried the same thing there…with the same results.  The wonderful thing about a reliably repeatable error is that it should be easier to fix or at least diagnose.  To that end I have submitted a Subscription Support request and provided journal files for review by the support gurus.

I am hoping they will buy me a six-pack…or at least restock the fridge…that’s what a true friend would do.  ;0)

Conceptual Energy Analysis inside Revit (5 of ?)

How’s that for a sexy image!  I know I’m likely to have just sent most of you running for a site with better graphics – CLICK (it’s safe, I promise).  But if you can muster and stick with me, I am pretty sure it will be worth it.

The Dialog Box

We all know that energy modeling is far more about the data than the geometry.  So in this post we will explore the data that Revit uses when creating a conceptual energy analysis.  The tough part of writing about this is the tangential way things are linked into this dialog box.  Although tangents can be fun at times.  That reminds me of a story.  This one time, at band camp… Oh, sorry.  There I go, off on a tangent.  I will try to stay focused.  Maybe more coffee will help.  I like coffee.  That reminds me of a story…

Okay, let’s get into it.  We are going to take this dialog box one section at a time.  First thing to mention is a not very obvious connection.  This Energy Settings dialog is the same dialog you get by going to Manage tab>Project Information>Energy Settings.  That is one thing I think the factory did well with CEA.  They didn’t create new dialogs, they just exposed and enhanced existing ones.

Common

In this first section of the dialog, you have three options to set: your building type, the ground level and your projects location. 

The Building Types gives some 33 building types to choose from.  Each building type is associated with a set of assumptions about its operation and use.  For example, the Hospital or Healthcare building type assumes certain values for sensible heat gain, light load density, operating schedule, infiltration flow, etc., that are different from an Exercise Center.  The actual values at this stage of the project are not really what’s important.  Since this tool is best for comparing various designs, choosing a building type and sticking with it is the most important. 

The ground level seems simple enough, right?  What level of your model defines the ground level around your building.  Important to note here is that Revit will make assumptions about the Conceptual Constructions of components that occur below your ground plane.  In other words, it will treat those elements as being under ground and will analyze them accordingly.

The Location setting is another example of how the factory smartly decided NOT to make a new dialog box.  Clicking the little nugget here takes you to the same place as if you had click Location from the Manage tab.  Be sure to pick a weather station location that makes sense for your project.  It might be the one physically closest, but not always.  Watch out for microclimate elements like bodies of water, hills or valleys around your site and pick a weather station that most closely represents the same kind of geography. 

Last note on the Common settings section:  These settings affect both the Conceptual Energy Analysis results as well as analysis in Revit MEP (using heating and cooling loads) and exporting a gbXML of a more developed model.

Detailed Model Settings

This is gonna be a quickie.  Nothing in this section of the dialog box affects the Conceptual Energy Analysis.  These settings do affect analysis in Revit MEP (using heating and cooling loads) and exporting a gbXML of a more developed model.  Also, check out the difference in the Detailed Model section between Revit Architecture (above) and Revit MEP (below).

This should illustrate to you that there is more information available to put into a gbXML from Revit MEP than from Revit Architecture.  But that is a discussion for a different post.

Energy Model

This is where the magic happens!  This is the control center for the Conceptual Energy Analysis tool.  It is so simple, yet so complex!  Ah, irony.  Don’t you love it?  It all starts with a simple check box.  The Create Energy Model check box makes the rest of this section come alive (literally).  Until you check the box, you can’t edit the parameter values.  So we check the box.  If we do nothing else and just click OK, Revit chugs away and generates zones and analytical surfaces based on the default values preset for the parameters in this section.  I would call this a baseline model, at least in terms of the CEA.  So what happens when we click OK?  This is what I’ve observed.  Follow along with the description in the image above.

• Revit divided each level into 5 zones:
  • A Core zone Offset 12’ back from the exterior face of the overall mass.
  • Revit created four Perimeter Zones, equal in area, around the Core zone. 
• Revit assigned Conceptual Constructions to the zones and surfaces.  (we’ll discuss this in more detail later)
• Revit created rectangular glazing on the exterior surfaces of each zone comprising of 40% of that surface. 
• Revit also set the sill height of this glazing to 2’-6”.
• Revit did not apply a 2’ deep shading device over each glazing area as the checkbox was unchecked. 
• Likewise, Revit did not make skylights on the top surface of the mass as the Target Percentage Skylights was set to 0%.

These are the defaults settings if you do nothing to the parameter values after checking the Create Energy Model checkbox.  Of course, if you so choose, you can manipulate these till your hearts content.  If you don’t want to generate a core zone, set the offset to 0’.  If you don’t want to divide the perimeter, uncheck the checkbox.  Etcetera, etcetera, etcetera.

One final note.  These setting, do not affect analysis in Revit MEP (using heating and cooling loads) or exporting a gbXML of a more developed model.  They only affect the Conceptual Energy Analysis.

Energy Model - Building Services

The last section of the Energy Settings dialog is small but important.  Only three parameters here:  Building Operating Schedule, HVAC System and Outdoor Air Information.  The values you see in the image directly above are the defaults.

The Default value for Building Operating Schedule means that the operating schedule is being taken from the Building Type setting in the Common section.  This parameter allows you to override the default by choosing from a list of operating schedules such as 24/7, 24/6, 12/7, Year-Round School, etc.  This provides further flexibility in your energy calculations. 

HVAC System allows you to choose from among different system configurations.  Personally, I don’t know enough about HVAC systems to be able to pick a good one, so I would need to ask an engineer.  What is displayed in the image above is the default system.

Outdoor Air Information is interesting.  By default it is blank (as shown below).  You can actually make multiple selections here.  Revit will choose which one to use in analysis depending on which produces the largest outdoor air volume.  The person count is set by the Building Type you picked; the area is found in the model and the air changes per hour is based on the operating schedule set - either by the Building Type or the override set in the Building Operating Schedule [CORRECTION] the number of times in one hour that the total volume of air in the building is replaced with outdoor air.

And again, like the Energy Model section, these setting do not affect analysis in Revit MEP (using heating and cooling loads) or exporting a gbXML of a more developed model.  They only affect the Conceptual Energy Analysis.

Wrap Up

All the data that you could ever want about the settings is available in the help menu.  More graphs and charts than you could dream of.  If you need to know exactly what the percent occupied assumption is for a 12/6 operating schedule on a Thursday at 6pm, you can find that. (It’s 40%).  Check out the Reference section of the help menu…you'll find it.

Next time, we’ll talk about custom zoning and glazing tools.

Wow that was long.  I’m exhausted.  I think I was able to stay on track…all that coffee paid off.  I like coffee.  That reminds me of a story…

Conceptual Energy Analysis inside Revit (4 of ?)

So the rose (or green) colored glasses are off.  I have found a chink in the armor of my Revit CEA knight.  One of the new features of the auto-magical Create Energy Model checkbox is this.  As soon as you create a mass and assign a mass floor, Revit CEA assumes you want to include it in the energy calculations. 

(If you don’t assign a mass floor, then it assumes the mass object is a shading object…something, like an adjacent building, that could cast shadows on your building.)

However, Revit CEA cannot create the analytical zones or surfaces if multiple masses overlap and are not joined.  So, checking the Create Energy Model automatically joins overlapping masses.  It is important to talk here about a couple of ways to create a unified mass from a few discrete masses.  First there is the Join Geometry tool.  Second there is the Cut Geometry tool.  The Join Geometry tool is what I first used and is what is used by CEA to automatically join overlapping masses (if the creator doesn’t join them before hitting finish mass).  When I tried to run an analysis I got the following error message:

What to do now?  I submitted a support request….and in the meantime I kept playing with it.  At first I was stumped.  I didn’t know what I did wrong.  So after some time zooming, panning and spinning the model, toggling the view between mass zones, mass surfaces and mass floors, I noticed something.  I could only see it in the mass zone view.  A small gap in the zoning surfaces was showing.

I tried the other method for joining two solids.  That is the Cut Geometry tool which cuts one solid from another.  As soon as I hit finish mass, the zoning model changed and the gap was gone.  I was able to send it up to Green Building Studio without error.

Aaahhhh, the sweet, sweet taste of victory!

So when subscription support responded back to me I happily told them what I had discovered and what I had done to fix it (their suggestion was to review the modeling best practice tips found in the CEA help menu).

The one thing that really irked me?  I had to hunt around for the problem.  The program did not tell me there was a gap in my zoning model.  Also, unlike when exporting a gbXML file from a more developed model, there is not a gbXML browser option that allows me to see the zones and surfaces in a tree structure and review them one by one.  So if the default zoning materials had not been translucent, I might never have seen the gap!

I have since expressed this to Autodesk through their Feedback page here.

I will get back on track with my next post which will be on the Energy Settings dialog and all that it controls.

Conceptual Energy Analysis inside Revit (3 of ?)

Now that we have developed a couple of options and run them through the Green Building Studio (GBS) “cloud”, let’s take a look at what we’ve got. Oooo, aaahhhh. Is it hot?

Or is is it cool?

I just don’t know. No, I do know…That’s hot!


Enough with the Pretty Pictures!


The pictures are nice, yes. But what do they really mean. What do they really tell you. This is where we turn to the Results & Compare tool. Within the Results and Compare window, you can select multiple analysis results (ctrl + click) and then select the all important Compare button. Now the real benefit comes out. We can look at our different Design Option runs against each other and, yes, you guessed it…


Compare!


Which one has the highest projected Annual Energy Use. Which one has the lowest projected Life Cycle Energy Use/Cost. Which one will sell more lollypops…okay maybe not that. But you can even see and compare some the Building Performance Factors like total Exterior Wall Area, Exterior Window Ratio and all the weather charts and graphs you could ever hope for. Oh joy, oh bliss…Calgon, take me away!

Now For You Skeptics



I know what you’re thinking. How are these tables calculated? These are mysterious numbers, maybe even magical numbers. Where do they come from? How do I know I can trust the data? What was that noise? Is someone watching me? I’m not paranoid…you’re paranoid!


Anywho…so I had these same thoughts…hey, I’m not a pessimist, I’m a realist. ;0) So I dug into the help menu. The information found by hitting F1 is pretty detailed. All of the reference material is available. The documentation states that the data used to make the assumptions on construction assemblies, building operations hours, etc. is based on ASHRAE Standards. There are many more charts, tables and graphs. But, I needed more. I am no engineer. Nor am I intimately familiar with ASHRAE standards. And I wondered, is this the right ASHRAE data? Is this the stuff that an architect should use at the conceptual level? So I asked for help from an energy modeling expert who’s credentials are beyond debate…he really knows his stuff. I asked him those questions.


HIs answer? Yes! This is good data per ASHRAE. Good for conceptual use by architects in comparing design alternatives. However, not good for predicting actual energy use. There simply isn’t enough data in the model to do that. But that’s okay. This is intended for use at the very early conceptual stage. Detailed analysis will come as the project moves forward. True and accurate simulation will be developed further down the road.


To Sum Up


Compare the results of multiple analysis runs within Revit from the Results and Compare window. Data is good. Lots of pretty graphics.


Oh yeah, and you can export a file filled with all the wonderful GBS data from the Results and Compare window to PDF (*.pdf), GBXml file(*.xml), DOE2 file(*.inp) for use in eQuest and Energy Plus file(*.idf).


Oh, oh yeah, and you can drag and drop the charts and graphs from the Results and Compare window directly onto a Revit sheet.


Next time we will get into the Energy Settings dialog and maybe even some of the new mass object subcategories. Until then, enjoy this random thought.


“I went out to find a friend and could not find one there. I went out to be a friend, and friends were everywhere.”

Conceptual Energy Analysis inside Revit (2 of ?)

So now that we are all familiar with the basics of Revit’s new Conceptual Energy Analysis tool (CEA for short), let’s talk about the real power here.  That is options.  We all like options, choices, selection.  Nobody likes to be told they have no choice.  What, you didn’t want brussels sprouts for dinner, you don’t like them, tough!

Design Options

Fortunately, Revit provides you, yes, you, you pork-pie-hat-black-cap-and-round-black-glasses wearing designer you, with options.  Totally, 100% customizable until your little heart’s content, options. 

Design Options have been around in Revit for quite some time now.  However their use is still sometimes steeped in myth and misinformation.  I have been trying to come up with a good analogy to explain the best use of them…so here goes.

Think of a Design Options set as a shot glass (yes a drinking analogy) and your model as your favorite bottle of booze…the liquor is the data in the model.  If your bottle has only one ounce of liquor in it, you could pour that whole ounce into your shot glass.  However, if your bottle is full, you shouldn’t try to pour the whole thing into the shot glass.  It will spill all over the place, make a big mess, you’ll be taunted and teased with jeers like “Dude, major party foul”.  So don’t over-pour!

To put it more directly, when you use Design Options you need to think in terms of data size.  You don’t want to put too much data in your Design Options.  Too much data and/or too many Design Options will significantly impact your model size and performance.  So for example, you could use Design Options to study multiple, whole building massing configurations.  This would be a large portion of model but relatively little data.  At the other end of the spectrum, you could do a study of a couple of rooms, including walls, rooms, equipment, etc.  This would be a smaller portion of the model but a large amount of data.

Okay, now that we have gotten that bit of formality out of the way, let us move on to cooler things.

Design Options for CEA

So you have a few design ideas.  Say you are designing a tower.  You want to explore some different shapes.  First you make a shape, boring, orthogonal, rectilinear, expected.  The good thing about this shape is that it is your baseline against which you can compare your other shapes.  In your next option, you give the top of your tower a twist, say 10 degrees clockwise about the center axis.  Nice, you’re feeling groovy.  But twisting towers have been done.  So you start to push and pull your edges and you make some canted surfaces.  Awesome, now your feeling so cool, you’re hot!  That’s hot!

Now, you know you need to get real.  You want to see which one is better in terms of potential energy use.  The CEA tool will send to the Green Building Studio (GBS)  “cloud” whichever design option is visible in your non-perspective 3D view.  That’s simple enough right?  Within your default 3D view, you just need to toggle through your various options using Visibility/Graphics and send each one off to GBS via the Analyze Mass Model button.  You don’t even need to wait until the results come back.  You can just keep on firing off options to the GBS cloud.  That’s the beauty and awesome power of the cloud…it can multitask!

When the results are ready to review, you get a cute, happy little dialog that very politely tells you your results are ready to review.

This ability to analyze multiple configurations and review their energy data is the true power of this new bell.  To quote Quasimodo, “The bells, the bells, I must ring the bells”.  And so we shall continue with the next post, when we will talk about the analysis results.