10/28/10

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.”

No comments:

Post a Comment