Energy Modeling for the Masses

For free, always has been, and I pray it always will be


eQUEST is the oldie but goodie fronting for the older and goodier DOE 2. 

Not a clue what I"m talking about
A long long time ago in a world far far away.....
A few visionaires started on the long and lonely road to create a way to model energy use in buildings.
The road branched endlessly, and each branch has had to be explored and mapped to discover enough to create a  functional building energy model (BEM for short).   most excellent history of Building Energy Modeling is available at the IBPSA USA BEMBOOK
Of the top choices to use in NYS / NYC for Building Energy Modeling, only one was up to the task of modeling an older building, which is over 1/2 our building stock.
The contenders were:
(These are number crunchers, not presentation heavy contenders, see below for more.)
RES Check
COM Check
Prescriptive Code:  NYC ECC
After running each contender through it's paces, the results were:
RES Check:  Fail
NYC ECC - prescriptive Tabular Analysis:  Fail
eQUEST:  Pass AND closely approximates actual energy use - See Below. 
The excellence and ease of modeling programs not withstanding, just like a dimension string, DUE DILIGENCE demands a reality check, in this case, by hand calcs - albeit, my hand creating an excel sheet.
For hand analysis of building energy use see below.

For the Pay Back / Life Cycle Costs for various energy conservation and alternative energy production initiatives for my old house(click here).


See bottom of page for more on why eQUEST works when other easy BEM systems fail.



It's what inside that counts...


Not in an image obsessed world.
Image, vision, graphics, clarity (which seems to mean - no words) and buzz sell.
Even in the cut and dry world of building energy modeling.
If you can't sell you're client on your design, your building, the architect who does may well not be as concerned with sustainability, with design, as with the presentation that will sell the design and get the building built.
There are a raft of new BEM products that produce FANTASTIC graphics.
You're likely more familiar with them then EQuest, Com or Res Check.

However, after you sell your sustainble design, what will get you the next green building client relies on your sustainable solution performing as predicted.  Every low energy building of yours becomes a giant buisness card for the world to see.  Every happy client will boast how much energy they've saved, generated and the money they've saved to one up their peers, be it the home owner next door, or the real estate tycoons at the next charity benefit.
Which is why you'll very likely need to run two energy models, or three. 
One energy model to produce the best graphics
One known accurate energy model you can work with to manipulate and model the architectural form to conserve as much energy / generate as much energy as possible.
One energy model your MEP will run to ensure no matter the weather, your ability to design / model for occupant comfort, that the building will be comfortable and completely usable for the client.  You don't need to worry about this being accurate, that is the primary engineering mantra.
Wow, that's alot of work.  Yes it is.  In time the market will condense.  Only time will tell what BEM software is accurately modeling energy use and alternative energy generation AND producing winning graphics.  Time as in decades.  Until then, you need to work harder and smarter to get ahead.  As it has always been and always will be.

Below are pdfs of the above slides. 

Much easier to read!

Document Library

DocumentCopy_7_of_2013-05-21_R_Higgins_2_Scenario 1
DocumentCopy_7_of_2013-05-21_R_Higgins_4_Scenario 3
DocumentCopy_7_of_2013-05-21_R_Higgins_5_Check with "hand" calcs
DocumentCopy_7_of_2013-05-21_R_Higgins_6_Check with "hand" calcs some more

Energy Modeling

NOT as hard as it looks

Practically, MOST  of the complexity in an energy model is in the MEP systems.

Don't worry about them!
You are an architect, you design the most energy efficent and beautiful building envelope, mass, and interiors that you can.
About solar gain, shading, wind......  DON'T, THAT IS WHAT THE SOFTWARE DOES SO WELL!
Retain the architectural  portions of the energy model for YOU to work with.
(For the most part you can model over and over again with no concern with what the MEP Engineers are cooking up system wise.  For, while MEP is a HUGE part of the energy budget of a building, your envelope, massing, layout is what will drive the energy use of the building.  It will drive what kind of MEP system and how it is implemented.  Your design, and energy model, will make or break the energy efficency of the building.  The cleverest MEP system can't save an inherently wasteful design, yet, the ultimate in energy conserving - and energy gathering design, PassivHaus - CAN make moot the most inefficent MEP system.)
Let the MEP engineers loose on "their" side of the model, collaborate to ensure your clients enviornmental needs are fully met, along with energy goals, but let the MEP's worry about the millions of minutia they'll need to input on every motor in the building. 
That means you need to learn how to import, export, and merge data files for your energy model. 
That's the only trick you'll need to learn.
Inputting the envelope, materials, massing and layout is at worst tedious, it is NOT difficult.
You, the architect, are now an expert energy modeler!

Metaphysicallly, the great complexity in Energy Modeling is a myth based on hope and hubris.

The hope that if we input enough info, the building will magically use no energy, despite floor to ceiling glass walls.
The hubris is that mankind can "model" nature. 
Nature is the ultimate analog system with infinite nested feedback systems keeping it in balance. 
Heat loss alone is a non-trivial physics problem.
To say the "hotter" something is, the "faster" it will loose heat is usually an understandable shortcut to most, but still a gross simplification of the problem in pinning down heat loss.
Heat loss varies by temperature, the inside temp, the outside temp, varying second by second, compounded by wind and humidity, and mediated by the intervening material temps, varying millimeter by millimeter and also endlessly varying, second by second.  Each unique combination of temperatures, materials, humidity, solar gain, sky cover (even at night), sky exposure, defines the heat transfer for the assembly, for that second in time. 


Why it works when others fail
Why YOU have to learn how to use it!
There is NOTHING wrong with ResCheck, ComCheck, and prescriptive codes, such as the NYC Energy Conservation Code.  They are good, the NYC Energy good is pretty agressive actually.
Two issues make these methodologies moot:
1.  OLD buildings
2.  Cutting edge buildings
The issue is "old building".  ResCheck, ComCheck, and the NYC ECC have no methodology to account for the huge variation is old builidngs, massive walls, earth coupling, high ceilings, transoms, denser and thicker woods, etc..  In new buildings, passive energy collection and distribution, ERV's - Energy Recovery Ventilators, etc..
Do you as an architect, a client, want to do avoid the hideous waste of demolishing an old building just to build a shiny new one, want to push the boundries of design and sustainable design? 
Then, you are going to have to learn at least one modeling program.  If you don't, you'll be chained to someone who can, with the economic burden and without the experiential intuition modeling will give you to shortcut to viable sustainble initiatives that work!
eQUEST and by inclusion, DOE2... are the defacto standards when building departments, gov't agencies, LEED, require BEM simulations to prove intent, compliance, qualify for incentives, and credentialling and kudos.  If you don't know a DOE2 compliant BEM, you might as well close up shop, CAD, Sketch up, 3D Studio Max, Maya, all USELESS to you if your design is not DOE2 compliant.
You'll let your engineer do it. 
Your engineer's bank account thanks you.
Your employee's won't as their bonus goes towards paying for the endless BEM sims.
Your clients won't as your designs loose their edge, and all begin to look like engineered buildings.
No engineer is going to futz around tweaking membrane components trying to find some combination of assembly and material U values, shading factors, solar gain coefficents, orientations that will make your building meet it's sustainable energy goals AND remain on the cutting edge of design.  To an engineer a wall is a wall is a wall, etc..  It's who they are, like to you an HVAC system is.... a big box on the roof.
  Back in the 70's and 80's, while most of BEM development and research was taking place, we did not have modeling software to help us determine what energy conservation and alternative energy production would be cost effective, or just plain do anything at all.

Instead, we relied on


Sustainability and Due Diligence - Pre BEM


Back in the 70's and 80's, while most of BEM development and research was taking place, we did not have modeling software to help us determine what energy conservation and alternative energy production would be cost effective, or just plain do anything at all.

Instead, we relied on VERNACULAR architecture and it's responses to similiar enviornmental conditions we were attempting to mitigate, lower energy use, save energy, etc.. There was usually a slight problem, the vernacular was probably not developed in a Western country, and that's we were trying to deploye the solutions.

Sustainability initiatives, green building techniques, even simple energy conservation must take into account the society, the culture around it, building users, owners, etc. or, it won't work as well as it could. The sustainability initiative might even fail entirely, which is bad for your project, and bad PR for the sustainability at large.

To be edited:
Remember that old adage
Was never better applied than to energy modeling
Rather than trying to input every tiny variation in your envelope, employ "safe sided" generalities. 
Which, is another web page I'll try to get together sooner than latter.