The Oregon rule set is in VS 3.63. I helped Scott put it there. When you
select your city in Oregon you will see the Oregon rules. In your email you
say 90.1-2004. The Oregon compliance rule set is probably 2004 I just don't
have time to confirm for sure.
Lynn Bellenger will soon be the first female president of ASHRAE..ASHRAE is
117 years young. Lynn's goal is to improve energy modeling. She is a PE and
a BEMP and a LEED AP. She has even more letters after her name but you will
have to ask her. She deserves every one of them. Lynn rocks. If I was a
betting woman, I would bet on Lynn to try to get this done. You will see I
have attempted to cc her on this. I have also bcc'd her to make sure she
gets the message.
I'm not sure I follow you. (Was this tongue in cheek?) What statistical
analysis are you referring to? I think the software certainly has its
limitations, but if you are aware of them you can certainly get useful
results. Perhaps you could clarify what you dislike about energy
modeling?
I suggest that you embrace the art part and get good at the science. Your
model will be just as good as your input. Whats that old saw? When you point
the finger you have 3 others pointing back at you. While some modeling tools
might be close to beta and hard to use, eQUEST isn't one of them. Each new
version has bugs, but those are relatively few and are fixed quickly. You
use energy modeling to predict the energy use and energy cost of a baseline
and proposed buildings. Here in Oregon we actually do follow-up and make
sure the predicted came close to the actual. We call it model verification.
I would recommend that you spend more time learning the art, gathering the
info, creating an actual weather file if the typical one's aren't good
enough for you, and very carefully inputting the data into your modeling
tool of choice. I'd be happy to offer you peer review services if you ever
want to make sure your work is accurate.
Best,
Carol
PS I resent the heck out of LEED paperwork and am afraid they are rulemaking
creativity out of buildings. I've seen it happen over, and over, and
over.....
Since Carol brought up the subject of improving energy modeling I would like to ask the following question.
What is the most appropriate and effective avenue to make suggestions for improvements to eQUEST and addressing potential problems?
One improvement I would like to see made to eQUEST is to add the pan function.
For my two cents worth, all computer simulations are relative to something,
not absolute. Energy baseline models are relative to actual utility bills.
Anything within 5-10% is considered solid. All proposed models are relative
to this good baseline. But as one of the replies mentioned this proposed
model should always be verified in the real world.
Same is true from my days in the auto industry. We create finite element
models to predict low and high speed crash simulations. We had actual
performance of previous production models to baseline from, but must always
verify by actual test. You would be amazed at how close we could get. Once
the model is correlated to the actual test results all variances built into
the model can be deemed reliable.
Building simulation models are much simpler, and in my mind very reliable -
if the inputs are correct. I have not tried all of the different modeling
tools, but eQuest provides a relatively friendly user-interface.
I am merely a young EIT of 2 and some-odd years, but I and surely most
other practicing MEP designer/modelers fully sympathize with your
frustrations. ASHRAE/IESNA 90.1 (and through it, LEED) is certainly not
yet a perfect standard... but the driving committees will be quick to
point out nobody is saying it is (and may solicit you to
volunteer/contribute to development). In any case, it's what we must
work under today... So we have to come to terms with the beast =)!
[ CAUTION: Skip this paragraph if you aren't interested in 90.1 nuances
- you'll risk glazing your eyes over! ]
The core baseline/proposed issues you mention are agreeably arguable on
a fundamental level! To pick up on your example, a glass box (well, up
to 40% technically) certainly has more opportunity to demonstrate
exemplary performance over its baseline than an opaque one under the
current ruleset. I think however most elements of the current
baseline/proposed system, including the flat 20% glazing alternative you
propose, is a damned-if-you-do/damned-if-you-don't situation for the
standard developers... In my modeling experience (from an annual energy
consumption/cost perspective): "optimal glazing percentages" are not
always 0% (sometimes they are), and can vary a LOT building-to-building
when daylighting controls enter the mix. Site shading, building element
self-shading, permanent/operable window shades, and orientations of
course all play vital roles in determining a meaningful optimal
window/wall ratio for any given space, but 90.1 Appendix G as written
nullifies each of these variables in a somewhat heavy-handed fashion for
the baseline model (sometimes the proposed also). I understand the
purpose of these measures is generally to help us easily determine
savings/losses based on a concept of "energy conscious building/site
orientation" (which I'd argue is kind of silly in and of itself), but
it's simultaneously dumbing-down our comparative results (moving them
further from reality). Removing self-shading/permanent shades for
example can both hurt and help the baseline/proposed comparative
performance - it's inconsistent depending on the climate and building
facade shape/orientation... I think these rules are built partly on the
assumption that shades are always beneficial for annual energy
consumption.
[ END OF CAUTION ]
To come back to the surface, I sleep at night by making one thing very
clear to any owners/architects that care to listen (though I've learned
some don't want to hear it): LEED-certified buildings, even those with
lots of energy modeling credits, do not inherently consume less energy
or pay lower utility bills than un-certified buildings*. Comparative
LEED energy models by design are not and should not be misconstrued by
building owners as modeling reality. As John touches on and Carol is
getting at: modeling "reality" before a building is built is guesswork
at best, and is much harder and more complex than earning any LEED
credits. Modeling "reality" post-construction and assuming historical
bills/behaviors will repeat themselves in the future is also
fundamentally guesswork - too much rides on the variability of actual
building occupant behavior and actual weather.
Not to cheapen anyone's credentials**, but when one fully understands
that all energy modeling is to some small/large degree guesswork, it's
so much easier to grasp that, even at its most complex, energy modeling
is simply a tool to make decisions with. In the right hands: a darn
useful tool, even =)!
~Nick
*If anyone isn't following - I would consider the following article
(notably dated) required reading for anyone practicing LEED energy
modeling, if only for practical perspective:
It's not hard to google and find similar studies - LEED buildings, even
those earning high certification levels, can easily consume more energy
than their un-certified modern counterparts.
If I can interject one point that hasn't really been discussed: LEED is not just an energy tool. Forgive me if I get some of the categories wrong, but as far as I am aware there are credits for daylight provision, water savings and... exceeding the minimum outdoor requirements.
I'm under the impression that even if Building A and B have the same energy consumption per SF (or whatever metric you'd like to compare them by) building A may provide users more fresh air, more outside views, uses less water and has xx% recycled materials.
I do believe that LEED needs some work, especially in regards to comparing operational energy consumption to designed energy consumption - My personal belief is to give a design rating that expires after a few years and that a building needs to PROVE that its operations are as efficient as the proposed design.
And briefly: I'll play devil's advocate and say that a building should be able to use as much GREEN energy as long as it's willing to pay for it. Sure, it's poor practice to leave lights on overnight, but if those lights are wind-powered ... well then there's no carbon emissions and it's just an expensive poor choice - not necessarily a climate-change inducing one.
Just because we are energy modelers doesn't mean we should lose focus on the fact that a "green" building can have implications beyond just energy use.
My 2?. I thought I would share it as I've enjoyed reading others' opinions on this very relevant topic.
And FYI - I too am a young professional in the field fueled more by a passion and a willingness to learn than great experience.
This is hands down the most interesting listserv discussion since Hornets
Nest in the year 2000. Search the archives. Kudos to those who have regular
paychecks and can thus write long, wonderful responses. I am self employed
and available to work for anyone. I love researching and answering questions
on this listserv, but must keep it to a minimum. I agree with many of you
and I think you know who you are. Earlier today, I purposefully brought this
back onto the listserv . IMHO that's where it needs to be.
Peace to all and don't forget to have fun and play, too.
Alex, if you look at how LEED-EB is progressing, don't be surprised if, in the not too distant future,?proving ongoing sustainable building operation will be requried to keep a LEED designation.
John,
Following up on Eric's post, what do you dislike about modeling? What is
the basis for your comments? It's a bold move to tell a group dedicated
to modeling to destroy modeling and say the work we do, the work many
people on this list have dedicated their lives to, is voodoo with no
meaningful results.
If you have real arguments with supported data and evidence, I would be
happy to listen.
As the one who started this post, I must say I have learned a lot.
Thank you very much.
What I have learned.
1. I have been misusing energy modeling. I have been trying to use energy
modeling for the sole purpose of earning LEED points.
2. I use it late in the design. Late in the design I have found it easier to
tweak my model instead of my design. (in order to get the desired number of
points)
(I do have integrity, so it kills me to "game" the system. But with
so few rules it wasn't hard to rationalize inputs. I go home not feeling
proud.)
3. When the goal is a realistic energy modeling, a very good model can be
created. When you are simply trying to reach compliance with some code, the
system can be gamed. This misuse and gaming of energy modeling is a waste of
time, but this is the users (MY) fault.
4. I need to get the other departments to realize that this isn't MY
(mechanical engineer) energy model, but OUR energy model. (I'm trying to get
my model done and the electrical engineer still doesn't have his light loads
and the Architect hasn't have a final roof design.)
I'm like a monkey hammering with a wrench. The frustration was a
misunderstanding of the tool.
I hope I can get the other departments on-board and maybe start using the
model as a design tool as it was intended.
To those who are being asked to misuse modeling, it is rough.
Once again, my frustration and stress with energy modeling was growing to the
point it disturbed my sleep. Having this discussion helped. The most
helpful was all the responses I received about the benefits of the proper use
of energy modeling, and empathy from others who know the pain of trying to
create a model just to earn points.
Ouch, maybe you shouldn't have admitted to #2/#3 below...there are a few members of the EAc1 TAG team that are part of this list :)
Don't let anyone force you to "misuse" an energy model. Period. You're the one with the power, so if an Architect is asking for results of a model but hasn't yet designed a lighting system or roofing system, you know where you can tell them to go (politely). As an engineer, that's one of my favorite parts of the job! And if someone is asking you to "take another look at the model" to see if you can get additional points, don't "game" the system! Sleep is too important...
In defense of LEED modeling: although I am not a LEED AP, I understand
that energy savings is not the primary goal. To judge it by energy
conservation standards, therefore, is unfair. My bag is energy
conservation program impact evaluation engineering, and I rely somewhat
on DOE2 modeling. To help circumvent the GIGO problem, I strive for as
much real audit data as possible and calibrate the models carefully to
customer billing data whenever possible. But I must admit that energy
conservation modeling results of buildings in the design stages must be
considered as unverified predictions (at least for a year or two). On
the other hand, if applied carefully by experienced engineers and
architects, they're generally more reliable than simpler methods, and
definitely better than nothing.
Perhaps it is time for the energy conservation community, including
myself, to push for something nationally in commercial building design
that strives for the same effect as Energy Star does for the residential
sector. But, recently, new energy codes seem to be going in that
direction with a reasonable level of aggression, if we can overcome the
problem of inconsistent enforcement.
John seems to have unusually strong negative feelings about the modeling
approach, but I appreciate his willingness to express his opinions
because they help keep (or make) us building energy modelers more honest
and humble.
I'd like to append a statement in support of Glenn and others: I am
most comfortable withholding from judging LEED in any positive or
negative light (as far as I'm concerned, it is what it is). There are
however individuals throughout the design chain, from
engineers/architects to building owners, who do misinterpret LEED's
broader purposes/intent as an effective energy conservation metric.
They do get upset when reality comes to light, which is exactly why I'm
making the point below that it's vital to educate anyone who will
listen, lest they blame the messenger (us modelers) when the utility
bills come in.
Amen, brother Nick. We are just users of the tools: LEED, eQUEST, etc. We
always are doing the best job we can. Some of us can do a better job than
others, of course. As we all learn more, and we do through this listserv, we
all raise the bar. Let's keep raising that bar!
1. I went room by room and input actual equipment. Example: I have 1
computer per person in a workstation. 155 Watts/computer from ASHRAE.
(Includes CPU and monitor)
1-A. Is this a constant 155Watts. Would the load be constant for printers,
projectors, refrigerators, dishwashers, microwave ovens, server rooms,
elevators?
2-B. I was given the server heat or rejection. Does the server really put
out that much at night also?
3-C. I use ASHRAE recommended values, but I assume these are for loads, not
hour-by-hour year round modeling. Are there other guides?
2. I currently have my infiltration set to 0.3 ACH for my exterior rooms.
2-A. Are there accepted or standard values?
2-B. Should I use ACH or cfm/sq ft of wall
2-C. Does the baseline and purposed need to be the same?
2-D. Is there a set standard for the baseline?
3. Thermostat.
(Positive note!! Instead of thinking of changing "night-time set back" values
as gaming, I should look at it as finding the best way to operate the system.
I think I am starting to understand!! If setting the thermostat back 10
degrees saves energy, I should do it! And the model shows me what to do!)
3-A. Besides the owner's request are there any rules for thermostats?
3-B. Some have modeled heating only spaces as having a cooling system but
set the thermostat set point very high so it would not turn on. Is this an
acceptable method? (Example- I have a mechanical room which is
cooled by an exhaust fan when the temp is above 80 degrees, I modeled the
unit to turn on when the temp reached 95 degrees. The result it the cooling
never turns on, since the exhaust fan offers enough cooling.)
4. Odd rooms. It is easy to model office spaces, but I have found
electrical rooms, mechanical rooms, elevator equipment rooms, vestibules,
stairwells, and server rooms to be lacking on guidance.
4-A. Is there any resources besides general judgment?
5. Minimal model. There is a lot of information which can be input.
Besides general gut feeling, how percise should the model be?
5-1. If I leave all the thermostat "by zone", and don't actually model the
thermostat in the room is this okay?
5-2. In an office, how do I schedule the meeting rooms? Do I show that the
population in the general office drops when everyone goes to the meeting?
Darn it! I've got work to be doing today but I'm a real sucker for
ethical discussions...
To get one thing out of the way first, call me a blind optimist, but I
reckon any EAc1 reviewer that subscribes to onebuilding.org lists is
probably a cut above their peers and will professionally avoid bringing
any unrelated postings into their current reviews. I sincerely hope
everyone agrees: these mailing-lists are an environment where we can
freely ask questions and demonstrate what we do and don't know. If
students were punished in a classroom for raising their hands, there
wouldn't be much learning going on.
It's weird to me however - when I was in school learning about
engineering ethics, it never dawned on me that energy modeling would
frame the context for the vast majority of my ethical decision making,
and that it would occur on a daily basis! I'm sure most of us strive to
do right by the system, within the constraints of our own ability and
time... but I'm also sure it is quite impossible to perform any LEED
EAc1 analysis without being forced to make subjective decisions
regarding 90.1/LEED intent and where to draw the line on "sufficiently
accurate" for a myriad of things.
So here's it is... my current take on LEED modeling & ethics (this has
certainly evolved over time):
1. Energy modeling for LEED is a game, USGBC reviewers are the Refs, and
the rest of us modelers are the Players who are charged with playing by
the rules of the game. Some of the Players are driven (personally or by
pressure) to earn as many points as possible, and others are not.
Exactly where you sit on that spectrum is an entirely personal and
non-ethical decision, it is NOT your employer's decision to make. It IS
an ethical dilemma anytime you knowingly break/bend the rules - whether
a Ref catches you or not. It's NOT an ethical issue if/when you should
seek to understand the nuances/intent of the rules better than others
and win the game by scoring more points. Like any game: Players with
more experience and understanding of the rules will naturally have a
higher potential to score legitimate points than players lacking either.
2. Players earning fewer points and the Refs who miss fouls (or must
justify their positions) will inevitably and understandably complain
about Players "gaming the system."
3. "Gaming the system" is a term (thrown around a bit loosely here,
imho) that implies bending/breaking the rules (unethical behavior), but
it's easy to confuse with trying to understand and act on the finer
points of the rules. I personally prefer to see phrases like "Working
within the system" used when that's what is meant. Why is this so
important that I made it a separate bullet? I and others will
rightfully take offense when anyone charges a fellow player of unethical
behavior without proper grounds, so please take care with that phrase.
As an aspiring Professional, I think I speak for a large group by saying
we take our ethical foundations very seriously - they are inseparable
and pertinent to the practice of energy modeling.
On a lighter note, I'll extend my analogy to tie back to the first
point: It would ALSO be an ethical dilemma if a Ref (USGBC reviewer)
were to dig into a Player's past history (these mailing list archives),
and decide to exact "punishment" for past behavior outside of the
project at-hand. John below is obviously interested in turning over a
new leaf, and he is NOT alone. Many of us (myself included) face a
daily struggle to maintain a personal ethical balance in our work. The
realities of deadlines, client/boss demands, inadequate
teamwork/communication on the design side, the need to prioritize
sleep/family time, and holistically the complexity of the entire process
can all work AGAINST those subjective ethical decisions we have to make
individually every time we pick up a project.
Then again... maybe some just don't think about this stuff too much?
On Thu, May 20, 2010 at 11:30 AM, Nick Caton wrote:
*Me too.*
*Doing anything out of fear should always be avoided. It's called being in
survival by some. For instance, some people can sit in a room by themselves
and cause whole groups of people to do what they say. They do this by
"controlling the purse strings". When we don't talk about something life
that it's like we are colluding with it. That's unethical.* Ignorance is
never bliss, is it?
*I agree 100%*
*Nick and I agree.*
*I agree. I always, purposefully err on the conservative side. My last
client actually questioned me about it: why was I showing xx % savings. Why
didn't I get 1.5 X xx%*
*Nick and I agree 100%*
*I agree, once again, with Nick. And, I am continually surprised by what
people say and do. I have heard the darnedest things*. The good news is, I
believe, that most LEED reviewers are also energy modeling practitioners.
I'm not sure that any of them aren't. If there are some LEED should not
contract with them.
*You and I and others continue to try to be the unpaid teachers, Nick. I
swear I am not going to teach anyone anything else for at least and hour.
HA!*
One of my favorite approaches when things aren't designed yet is to make a
responsible assumption and use it in the model. With the model results, my
clients get a list of assumptions and inputs. This way you can use the
model to push the designers to create a responsible design. The lighting
designer hasn't finished designing yet? OK, enter 0.6 w/sf in your model
push them to get their power density down while still providing enough
light! You can do the same with the building envelope, mechanical systems,
etc. If things are not finished, this also opens the opportunity for you to
get involved and help the design team create the design. Show them the
difference with model results between x and y. Show them how good their
building can be, if they want it to. This does mean that the model has to
be re-worked when it's time to submit LEED documentation to reflect what is
actually provided, but it's a small price to pay.
I can tell you some of the assumptions I routinely make for energy models, but what you should use always depends on what the goals for the energy model are.
Kelsey Van Tassel
General questions:
1. I went room by room and input actual equipment. Example: I have 1
computer per person in a workstation. 155 Watts/computer from ASHRAE.
(Includes CPU and monitor)
1-A. Is this a constant 155Watts. Would the load be constant for printers,
projectors, refrigerators, dishwashers, microwave ovens, server rooms,
elevators?
No, the loads are probably not constant. The easiest thing to do would be to make a reasonable estimate for how much power is consumed when some or most of the equipment is on (it is unlikely that every single piece of equipment would be on at full power all at once, though). Input that power density into eQUEST and make sure that the hour-by-hour profile (consisting of fractions of that peak load) is reasonable based on your occupancy schedule.
2-B. I was given the server heat or rejection. Does the server really put
out that much at night also?
Maybe. Were you given a maximum or an average? Did you set up a separate schedule for the server load?
3-C. I use ASHRAE recommended values, but I assume these are for loads, not
hour-by-hour year round modeling. Are there other guides?
I use Table N2-3 from the California Nonresidential ACM Approval Manual which lists receptacle loads found from a study conducted by Lawrence Berkeley National Laboratory.
2. I currently have my infiltration set to 0.3 ACH for my exterior rooms.
2-A. Are there accepted or standard values?
Section 27.23 in the 2005 ASHRAE Handbook of Fundamentals discusses Nonresidential Air Leakage. In it, they cite a 1976 study done on 8 Canadian Office buildings with sealed windows which showed an average air leakage rate between 0.12 and 0.48 cfm/sq ft wall area. I have been using 0.12 cfm/sq ft wall area for perimeter spaces for all of my models unless I am specifically studying infiltration reduction. This value is about 3 times higher than the eQUEST default.
I would be interested if anyone knows of any more recent or comprehensive studies.
2-B. Should I use ACH or cfm/sq ft of wall
It doesn't matter. eQUEST treats both the same. There are other infiltration calculation methods available in detail mode, but they are mostly for residential buildings, I think.
2-C. Does the baseline and purposed need to be the same?
It depends on what the energy model is intended to show. But in general, the weather file, occupancy schedules, building footprint and floor plans and process loads are kept the same.
2-D. Is there a set standard for the baseline?
Depends on what type of energy modeling you are doing. If it is for LEED, you must follow ASHRAE Standard 90.1 Appendix G. State incentive programs, utility programs and energy tax credit rules will all have different requirements for the baseline model. If you are trying to show energy savings of upgrades to an existing building, your baseline will be the current as-built design.
3. Thermostat.
(Positive note!! Instead of thinking of changing "night-time set back" values
as gaming, I should look at it as finding the best way to operate the system.
I think I am starting to understand!! If setting the thermostat back 10
degrees saves energy, I should do it! And the model shows me what to do!)
Sure, just be careful that the assumptions you are making are realistic.
3-A. Besides the owner's request are there any rules for thermostats?
Just to be careful. You may be able to model controls that are not really realistic. Such as having a very narrow deadband (difference between setpoints for heating and cooling mode) or temperatures that are controlled very precisely to within 0.5 deg.
3-B. Some have modeled heating only spaces as having a cooling system but
set the thermostat set point very high so it would not turn on. Is this an
acceptable method? (Example- I have a mechanical room which is
cooled by an exhaust fan when the temp is above 80 degrees, I modeled the
unit to turn on when the temp reached 95 degrees. The result it the cooling
never turns on, since the exhaust fan offers enough cooling.)
That is one way to do it. In rooms where the temperature is allowed to float, I remove the heating and/or cooling t-stat schedules entirely.
4. Odd rooms. It is easy to model office spaces, but I have found
electrical rooms, mechanical rooms, elevator equipment rooms, vestibules,
stairwells, and server rooms to be lacking on guidance.
4-A. Is there any resources besides general judgment?
I generally find these types of rooms fairly easy to model since they usually do not contain people for any significant amount of time. Ventilation or exhaust is determined by square footage. The hardest part is determining an appropriate receptacle load.
5. Minimal model. There is a lot of information which can be input.
Besides general gut feeling, how percise should the model be?
This again depends on the goals for the energy model.
5-1. If I leave all the thermostat "by zone", and don't actually model the
thermostat in the room is this okay?
It could be. Would all the rooms normally have individual thermostats? Are you grouping only similar rooms?
5-2. In an office, how do I schedule the meeting rooms? Do I show that the
population in the general office drops when everyone goes to the meeting?
Unless you have the building divided up into multiple shells, there is only one occupancy schedule that is the average for the entire building.
It's late on a Friday night, and watching TV is boring, so here are my thoughts on this topic/thread. I hope they are useful to somebody.
Way back in the email chain, somebody said that what they did in energy modeling had no effect on the construction drawings. That is a realistic result for some projects, but unfortunate. I share the frustration because I have worked on projects like that in the past. However, if we energy modelers are doing our jobs, we should be pushing the designers, and giving them feedback early on in the design process. But we have to step up and do that. We can't be a mouse and cannot just complain about the architect and engineering design team members not paying attention to the energy. Go educate them, & insert yourself in the design process. Give them the feedback that Karen has described. Measure your success not by how many LEED points the project earns, but by the fact that you helped the design team change something about the building so that it is more efficient in the real world (i.e. better wall insulation, better glass selection, better light fixtures, higher efficiency HVAC equipment, etc.). I like how somebody put it earlier in that energy modeling is for making decisions. If you helped the design team make some decisions, consider your effort a success. If your energy modeling resulted in nothing different in the construction documents, figure out why and fast because you are not adding value to the design process, which could be detrimental to your employment status. My personal opinion is that I do not think an energy modeling profession will survive solely to estimate LEED point for completed designs. If that is all we are doing, I think the building owners will figure out a way to eliminate us and our corresponding fees.
I think all energy modelers should read the document available from Energy Design Resources, called "Advanced Simulation Guidebook Volume II - The High Performance Building Process"
This document has some good thoughts regarding energy modeling and the design process.
This document correctly relays the fact that some kind of feedback early on in the design phase is a lot better than detailed modeling late in the game when the CD's are near 100% & little can be changed.
Don't get focused on making everything perfect or more detailed than it needs to be, especially if that is holding up getting decision making information to the design team. The thing about design teams is that they will make the decisions with or without you and move on to meet the deadline.
Finally, real buildings can and usually will operate far differently than our energy models suggest. If you really care about buildings using less energy, focus more on going into real buildings and helping the operators and owners figure out the best way to operate them to reduce energy. This gets into the M&V area, which I think all energy modelers should be focused on going forward because it can add real value. To that end, I will leave the group with one final bit of advice. Check out the Universal Translator freeware program available from the following website: http://utonline.org/cms/
I was very excited to find that this program existed because, in a nutshell, this program allows you to very easily work with real data from real building automation systems to figure out what the heck is going on in the buildings that are using too much energy. The UT program is developed by the Pacific Energy Center of PG&E.
Lots of good programs come out of California (which I'm very grateful for), like eQuest & now the Universal Translator. Add the UT to your toolkit. I think you will find the program to be very valuable.
Does anyone have experience?on?creating an energy model?for an industrial facility to satisfy LEED?EAc1 and EAp2?
?
ASHRAE 90.1.2007?says (2.Scope - page 4), you do not?need to follow 90.1?if it is?an industrial, manufaturing or commerical process facilities. Please share your experience on how to develop a baseline model.
?
Regards,
?
Senthil kumar a r
Hi Curt.
The Oregon rule set is in VS 3.63. I helped Scott put it there. When you
select your city in Oregon you will see the Oregon rules. In your email you
say 90.1-2004. The Oregon compliance rule set is probably 2004 I just don't
have time to confirm for sure.
Good Luck,
Carol
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Hello Scott,
Thanks for the help on this question.
Is there anything available now or in the works for ASHRAE 90.1-2004 or 2007 compliance analysis?
Thanks again,
Paul
Paul Buchheit
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All,
Lynn Bellenger will soon be the first female president of ASHRAE..ASHRAE is
117 years young. Lynn's goal is to improve energy modeling. She is a PE and
a BEMP and a LEED AP. She has even more letters after her name but you will
have to ask her. She deserves every one of them. Lynn rocks. If I was a
betting woman, I would bet on Lynn to try to get this done. You will see I
have attempted to cc her on this. I have also bcc'd her to make sure she
gets the message.
A good night to all and to all a good night!
Carol
I would prefer Lynn work to ban/destroy/do-away-with energy modeling.
Any chance this voo-doo engineering will go away any time soon? It is only
statistical analysis with no meaningful/useful results for anyone.
As a community I think we are going in the wrong direction for the right
goals.
John,
I'm not sure I follow you. (Was this tongue in cheek?) What statistical
analysis are you referring to? I think the software certainly has its
limitations, but if you are aware of them you can certainly get useful
results. Perhaps you could clarify what you dislike about energy
modeling?
Cheers,
Eric
John, you army guy you...
I suggest that you embrace the art part and get good at the science. Your
model will be just as good as your input. Whats that old saw? When you point
the finger you have 3 others pointing back at you. While some modeling tools
might be close to beta and hard to use, eQUEST isn't one of them. Each new
version has bugs, but those are relatively few and are fixed quickly. You
use energy modeling to predict the energy use and energy cost of a baseline
and proposed buildings. Here in Oregon we actually do follow-up and make
sure the predicted came close to the actual. We call it model verification.
I would recommend that you spend more time learning the art, gathering the
info, creating an actual weather file if the typical one's aren't good
enough for you, and very carefully inputting the data into your modeling
tool of choice. I'd be happy to offer you peer review services if you ever
want to make sure your work is accurate.
Best,
Carol
PS I resent the heck out of LEED paperwork and am afraid they are rulemaking
creativity out of buildings. I've seen it happen over, and over, and
over.....
Hello All,
Since Carol brought up the subject of improving energy modeling I would like to ask the following question.
What is the most appropriate and effective avenue to make suggestions for improvements to eQUEST and addressing potential problems?
One improvement I would like to see made to eQUEST is to add the pan function.
Thanks,
Paul Buchheit
For my two cents worth, all computer simulations are relative to something,
not absolute. Energy baseline models are relative to actual utility bills.
Anything within 5-10% is considered solid. All proposed models are relative
to this good baseline. But as one of the replies mentioned this proposed
model should always be verified in the real world.
Same is true from my days in the auto industry. We create finite element
models to predict low and high speed crash simulations. We had actual
performance of previous production models to baseline from, but must always
verify by actual test. You would be amazed at how close we could get. Once
the model is correlated to the actual test results all variances built into
the model can be deemed reliable.
Building simulation models are much simpler, and in my mind very reliable -
if the inputs are correct. I have not tried all of the different modeling
tools, but eQuest provides a relatively friendly user-interface.
Gregory Sarkisian, P.E.
John et al,
I am merely a young EIT of 2 and some-odd years, but I and surely most
other practicing MEP designer/modelers fully sympathize with your
frustrations. ASHRAE/IESNA 90.1 (and through it, LEED) is certainly not
yet a perfect standard... but the driving committees will be quick to
point out nobody is saying it is (and may solicit you to
volunteer/contribute to development). In any case, it's what we must
work under today... So we have to come to terms with the beast =)!
[ CAUTION: Skip this paragraph if you aren't interested in 90.1 nuances
- you'll risk glazing your eyes over! ]
The core baseline/proposed issues you mention are agreeably arguable on
a fundamental level! To pick up on your example, a glass box (well, up
to 40% technically) certainly has more opportunity to demonstrate
exemplary performance over its baseline than an opaque one under the
current ruleset. I think however most elements of the current
baseline/proposed system, including the flat 20% glazing alternative you
propose, is a damned-if-you-do/damned-if-you-don't situation for the
standard developers... In my modeling experience (from an annual energy
consumption/cost perspective): "optimal glazing percentages" are not
always 0% (sometimes they are), and can vary a LOT building-to-building
when daylighting controls enter the mix. Site shading, building element
self-shading, permanent/operable window shades, and orientations of
course all play vital roles in determining a meaningful optimal
window/wall ratio for any given space, but 90.1 Appendix G as written
nullifies each of these variables in a somewhat heavy-handed fashion for
the baseline model (sometimes the proposed also). I understand the
purpose of these measures is generally to help us easily determine
savings/losses based on a concept of "energy conscious building/site
orientation" (which I'd argue is kind of silly in and of itself), but
it's simultaneously dumbing-down our comparative results (moving them
further from reality). Removing self-shading/permanent shades for
example can both hurt and help the baseline/proposed comparative
performance - it's inconsistent depending on the climate and building
facade shape/orientation... I think these rules are built partly on the
assumption that shades are always beneficial for annual energy
consumption.
[ END OF CAUTION ]
To come back to the surface, I sleep at night by making one thing very
clear to any owners/architects that care to listen (though I've learned
some don't want to hear it): LEED-certified buildings, even those with
lots of energy modeling credits, do not inherently consume less energy
or pay lower utility bills than un-certified buildings*. Comparative
LEED energy models by design are not and should not be misconstrued by
building owners as modeling reality. As John touches on and Carol is
getting at: modeling "reality" before a building is built is guesswork
at best, and is much harder and more complex than earning any LEED
credits. Modeling "reality" post-construction and assuming historical
bills/behaviors will repeat themselves in the future is also
fundamentally guesswork - too much rides on the variability of actual
building occupant behavior and actual weather.
Not to cheapen anyone's credentials**, but when one fully understands
that all energy modeling is to some small/large degree guesswork, it's
so much easier to grasp that, even at its most complex, energy modeling
is simply a tool to make decisions with. In the right hands: a darn
useful tool, even =)!
~Nick
*If anyone isn't following - I would consider the following article
(notably dated) required reading for anyone practicing LEED energy
modeling, if only for practical perspective:
http://www.buildingscience.com/documents/insights/mis2014leed2014ing/
This is notably a sidebar to the following, also insightful &
tongue-in-cheek article by the same author:
http://www.buildingscience.com/documents/insights/bsi-007-prioritizing-g
reen2014it-s-the-energy-stupid
It's not hard to google and find similar studies - LEED buildings, even
those earning high certification levels, can easily consume more energy
than their un-certified modern counterparts.
** I know, easy for me to say!
NICK CATON, E.I.T.
All,
If I can interject one point that hasn't really been discussed: LEED is not just an energy tool. Forgive me if I get some of the categories wrong, but as far as I am aware there are credits for daylight provision, water savings and... exceeding the minimum outdoor requirements.
I'm under the impression that even if Building A and B have the same energy consumption per SF (or whatever metric you'd like to compare them by) building A may provide users more fresh air, more outside views, uses less water and has xx% recycled materials.
I do believe that LEED needs some work, especially in regards to comparing operational energy consumption to designed energy consumption - My personal belief is to give a design rating that expires after a few years and that a building needs to PROVE that its operations are as efficient as the proposed design.
And briefly: I'll play devil's advocate and say that a building should be able to use as much GREEN energy as long as it's willing to pay for it. Sure, it's poor practice to leave lights on overnight, but if those lights are wind-powered ... well then there's no carbon emissions and it's just an expensive poor choice - not necessarily a climate-change inducing one.
Just because we are energy modelers doesn't mean we should lose focus on the fact that a "green" building can have implications beyond just energy use.
My 2?. I thought I would share it as I've enjoyed reading others' opinions on this very relevant topic.
And FYI - I too am a young professional in the field fueled more by a passion and a willingness to learn than great experience.
Cheers,
Alex Krickx
This is hands down the most interesting listserv discussion since Hornets
Nest in the year 2000. Search the archives. Kudos to those who have regular
paychecks and can thus write long, wonderful responses. I am self employed
and available to work for anyone. I love researching and answering questions
on this listserv, but must keep it to a minimum. I agree with many of you
and I think you know who you are. Earlier today, I purposefully brought this
back onto the listserv . IMHO that's where it needs to be.
Peace to all and don't forget to have fun and play, too.
Carol Gardner PE
Alex, if you look at how LEED-EB is progressing, don't be surprised if, in the not too distant future,?proving ongoing sustainable building operation will be requried to keep a LEED designation.
?
Do you mean we all will have to pay the big bucks to LEED to join them and
take their test? Too expensive for me!
No offense intended to anyone, ever.
Carol
John,
Following up on Eric's post, what do you dislike about modeling? What is
the basis for your comments? It's a bold move to tell a group dedicated
to modeling to destroy modeling and say the work we do, the work many
people on this list have dedicated their lives to, is voodoo with no
meaningful results.
If you have real arguments with supported data and evidence, I would be
happy to listen.
Sam Mason
As the one who started this post, I must say I have learned a lot.
Thank you very much.
What I have learned.
1. I have been misusing energy modeling. I have been trying to use energy
modeling for the sole purpose of earning LEED points.
2. I use it late in the design. Late in the design I have found it easier to
tweak my model instead of my design. (in order to get the desired number of
points)
(I do have integrity, so it kills me to "game" the system. But with
so few rules it wasn't hard to rationalize inputs. I go home not feeling
proud.)
3. When the goal is a realistic energy modeling, a very good model can be
created. When you are simply trying to reach compliance with some code, the
system can be gamed. This misuse and gaming of energy modeling is a waste of
time, but this is the users (MY) fault.
4. I need to get the other departments to realize that this isn't MY
(mechanical engineer) energy model, but OUR energy model. (I'm trying to get
my model done and the electrical engineer still doesn't have his light loads
and the Architect hasn't have a final roof design.)
I'm like a monkey hammering with a wrench. The frustration was a
misunderstanding of the tool.
I hope I can get the other departments on-board and maybe start using the
model as a design tool as it was intended.
To those who are being asked to misuse modeling, it is rough.
Once again, my frustration and stress with energy modeling was growing to the
point it disturbed my sleep. Having this discussion helped. The most
helpful was all the responses I received about the benefits of the proper use
of energy modeling, and empathy from others who know the pain of trying to
create a model just to earn points.
Thank you all,
John Eurek
Ouch, maybe you shouldn't have admitted to #2/#3 below...there are a few members of the EAc1 TAG team that are part of this list :)
Don't let anyone force you to "misuse" an energy model. Period. You're the one with the power, so if an Architect is asking for results of a model but hasn't yet designed a lighting system or roofing system, you know where you can tell them to go (politely). As an engineer, that's one of my favorite parts of the job! And if someone is asking you to "take another look at the model" to see if you can get additional points, don't "game" the system! Sleep is too important...
James Hansen, PE, LEED AP
Go with god, son. If you want a double check on whether you made a
reasonable change vs gamed the system, hire one of us peer reviewers.
Carol
In defense of LEED modeling: although I am not a LEED AP, I understand
that energy savings is not the primary goal. To judge it by energy
conservation standards, therefore, is unfair. My bag is energy
conservation program impact evaluation engineering, and I rely somewhat
on DOE2 modeling. To help circumvent the GIGO problem, I strive for as
much real audit data as possible and calibrate the models carefully to
customer billing data whenever possible. But I must admit that energy
conservation modeling results of buildings in the design stages must be
considered as unverified predictions (at least for a year or two). On
the other hand, if applied carefully by experienced engineers and
architects, they're generally more reliable than simpler methods, and
definitely better than nothing.
Perhaps it is time for the energy conservation community, including
myself, to push for something nationally in commercial building design
that strives for the same effect as Energy Star does for the residential
sector. But, recently, new energy codes seem to be going in that
direction with a reasonable level of aggression, if we can overcome the
problem of inconsistent enforcement.
John seems to have unusually strong negative feelings about the modeling
approach, but I appreciate his willingness to express his opinions
because they help keep (or make) us building energy modelers more honest
and humble.
Yours truly,
Glenn
I'd like to append a statement in support of Glenn and others: I am
most comfortable withholding from judging LEED in any positive or
negative light (as far as I'm concerned, it is what it is). There are
however individuals throughout the design chain, from
engineers/architects to building owners, who do misinterpret LEED's
broader purposes/intent as an effective energy conservation metric.
They do get upset when reality comes to light, which is exactly why I'm
making the point below that it's vital to educate anyone who will
listen, lest they blame the messenger (us modelers) when the utility
bills come in.
~Nick
NICK CATON, E.I.T.
Amen, brother Nick. We are just users of the tools: LEED, eQUEST, etc. We
always are doing the best job we can. Some of us can do a better job than
others, of course. As we all learn more, and we do through this listserv, we
all raise the bar. Let's keep raising that bar!
Carol
General questions:
1. I went room by room and input actual equipment. Example: I have 1
computer per person in a workstation. 155 Watts/computer from ASHRAE.
(Includes CPU and monitor)
1-A. Is this a constant 155Watts. Would the load be constant for printers,
projectors, refrigerators, dishwashers, microwave ovens, server rooms,
elevators?
2-B. I was given the server heat or rejection. Does the server really put
out that much at night also?
3-C. I use ASHRAE recommended values, but I assume these are for loads, not
hour-by-hour year round modeling. Are there other guides?
2. I currently have my infiltration set to 0.3 ACH for my exterior rooms.
2-A. Are there accepted or standard values?
2-B. Should I use ACH or cfm/sq ft of wall
2-C. Does the baseline and purposed need to be the same?
2-D. Is there a set standard for the baseline?
3. Thermostat.
(Positive note!! Instead of thinking of changing "night-time set back" values
as gaming, I should look at it as finding the best way to operate the system.
I think I am starting to understand!! If setting the thermostat back 10
degrees saves energy, I should do it! And the model shows me what to do!)
3-A. Besides the owner's request are there any rules for thermostats?
3-B. Some have modeled heating only spaces as having a cooling system but
set the thermostat set point very high so it would not turn on. Is this an
acceptable method? (Example- I have a mechanical room which is
cooled by an exhaust fan when the temp is above 80 degrees, I modeled the
unit to turn on when the temp reached 95 degrees. The result it the cooling
never turns on, since the exhaust fan offers enough cooling.)
4. Odd rooms. It is easy to model office spaces, but I have found
electrical rooms, mechanical rooms, elevator equipment rooms, vestibules,
stairwells, and server rooms to be lacking on guidance.
4-A. Is there any resources besides general judgment?
5. Minimal model. There is a lot of information which can be input.
Besides general gut feeling, how percise should the model be?
5-1. If I leave all the thermostat "by zone", and don't actually model the
thermostat in the room is this okay?
5-2. In an office, how do I schedule the meeting rooms? Do I show that the
population in the general office drops when everyone goes to the meeting?
Darn it! I've got work to be doing today but I'm a real sucker for
ethical discussions...
To get one thing out of the way first, call me a blind optimist, but I
reckon any EAc1 reviewer that subscribes to onebuilding.org lists is
probably a cut above their peers and will professionally avoid bringing
any unrelated postings into their current reviews. I sincerely hope
everyone agrees: these mailing-lists are an environment where we can
freely ask questions and demonstrate what we do and don't know. If
students were punished in a classroom for raising their hands, there
wouldn't be much learning going on.
It's weird to me however - when I was in school learning about
engineering ethics, it never dawned on me that energy modeling would
frame the context for the vast majority of my ethical decision making,
and that it would occur on a daily basis! I'm sure most of us strive to
do right by the system, within the constraints of our own ability and
time... but I'm also sure it is quite impossible to perform any LEED
EAc1 analysis without being forced to make subjective decisions
regarding 90.1/LEED intent and where to draw the line on "sufficiently
accurate" for a myriad of things.
So here's it is... my current take on LEED modeling & ethics (this has
certainly evolved over time):
1. Energy modeling for LEED is a game, USGBC reviewers are the Refs, and
the rest of us modelers are the Players who are charged with playing by
the rules of the game. Some of the Players are driven (personally or by
pressure) to earn as many points as possible, and others are not.
Exactly where you sit on that spectrum is an entirely personal and
non-ethical decision, it is NOT your employer's decision to make. It IS
an ethical dilemma anytime you knowingly break/bend the rules - whether
a Ref catches you or not. It's NOT an ethical issue if/when you should
seek to understand the nuances/intent of the rules better than others
and win the game by scoring more points. Like any game: Players with
more experience and understanding of the rules will naturally have a
higher potential to score legitimate points than players lacking either.
2. Players earning fewer points and the Refs who miss fouls (or must
justify their positions) will inevitably and understandably complain
about Players "gaming the system."
3. "Gaming the system" is a term (thrown around a bit loosely here,
imho) that implies bending/breaking the rules (unethical behavior), but
it's easy to confuse with trying to understand and act on the finer
points of the rules. I personally prefer to see phrases like "Working
within the system" used when that's what is meant. Why is this so
important that I made it a separate bullet? I and others will
rightfully take offense when anyone charges a fellow player of unethical
behavior without proper grounds, so please take care with that phrase.
As an aspiring Professional, I think I speak for a large group by saying
we take our ethical foundations very seriously - they are inseparable
and pertinent to the practice of energy modeling.
On a lighter note, I'll extend my analogy to tie back to the first
point: It would ALSO be an ethical dilemma if a Ref (USGBC reviewer)
were to dig into a Player's past history (these mailing list archives),
and decide to exact "punishment" for past behavior outside of the
project at-hand. John below is obviously interested in turning over a
new leaf, and he is NOT alone. Many of us (myself included) face a
daily struggle to maintain a personal ethical balance in our work. The
realities of deadlines, client/boss demands, inadequate
teamwork/communication on the design side, the need to prioritize
sleep/family time, and holistically the complexity of the entire process
can all work AGAINST those subjective ethical decisions we have to make
individually every time we pick up a project.
Then again... maybe some just don't think about this stuff too much?
~Nick
NICK CATON, E.I.T.
On Thu, May 20, 2010 at 11:30 AM, Nick Catonwrote:
*Me too.*
*Doing anything out of fear should always be avoided. It's called being in
survival by some. For instance, some people can sit in a room by themselves
and cause whole groups of people to do what they say. They do this by
"controlling the purse strings". When we don't talk about something life
that it's like we are colluding with it. That's unethical.* Ignorance is
never bliss, is it?
*I agree 100%*
*Nick and I agree.*
*I agree. I always, purposefully err on the conservative side. My last
client actually questioned me about it: why was I showing xx % savings. Why
didn't I get 1.5 X xx%*
*Nick and I agree 100%*
*I agree, once again, with Nick. And, I am continually surprised by what
people say and do. I have heard the darnedest things*. The good news is, I
believe, that most LEED reviewers are also energy modeling practitioners.
I'm not sure that any of them aren't. If there are some LEED should not
contract with them.
*You and I and others continue to try to be the unpaid teachers, Nick. I
swear I am not going to teach anyone anything else for at least and hour.
HA!*
*PS write when you find work.......
Mom*
--
Carol Gardner PE
One of my favorite approaches when things aren't designed yet is to make a
responsible assumption and use it in the model. With the model results, my
clients get a list of assumptions and inputs. This way you can use the
model to push the designers to create a responsible design. The lighting
designer hasn't finished designing yet? OK, enter 0.6 w/sf in your model
push them to get their power density down while still providing enough
light! You can do the same with the building envelope, mechanical systems,
etc. If things are not finished, this also opens the opportunity for you to
get involved and help the design team create the design. Show them the
difference with model results between x and y. Show them how good their
building can be, if they want it to. This does mean that the model has to
be re-worked when it's time to submit LEED documentation to reflect what is
actually provided, but it's a small price to pay.
--
Karen
I can tell you some of the assumptions I routinely make for energy models, but what you should use always depends on what the goals for the energy model are.
Kelsey Van Tassel
General questions:
1. I went room by room and input actual equipment. Example: I have 1
computer per person in a workstation. 155 Watts/computer from ASHRAE.
(Includes CPU and monitor)
1-A. Is this a constant 155Watts. Would the load be constant for printers,
projectors, refrigerators, dishwashers, microwave ovens, server rooms,
elevators?
No, the loads are probably not constant. The easiest thing to do would be to make a reasonable estimate for how much power is consumed when some or most of the equipment is on (it is unlikely that every single piece of equipment would be on at full power all at once, though). Input that power density into eQUEST and make sure that the hour-by-hour profile (consisting of fractions of that peak load) is reasonable based on your occupancy schedule.
2-B. I was given the server heat or rejection. Does the server really put
out that much at night also?
Maybe. Were you given a maximum or an average? Did you set up a separate schedule for the server load?
3-C. I use ASHRAE recommended values, but I assume these are for loads, not
hour-by-hour year round modeling. Are there other guides?
I use Table N2-3 from the California Nonresidential ACM Approval Manual which lists receptacle loads found from a study conducted by Lawrence Berkeley National Laboratory.
2. I currently have my infiltration set to 0.3 ACH for my exterior rooms.
2-A. Are there accepted or standard values?
Section 27.23 in the 2005 ASHRAE Handbook of Fundamentals discusses Nonresidential Air Leakage. In it, they cite a 1976 study done on 8 Canadian Office buildings with sealed windows which showed an average air leakage rate between 0.12 and 0.48 cfm/sq ft wall area. I have been using 0.12 cfm/sq ft wall area for perimeter spaces for all of my models unless I am specifically studying infiltration reduction. This value is about 3 times higher than the eQUEST default.
I would be interested if anyone knows of any more recent or comprehensive studies.
2-B. Should I use ACH or cfm/sq ft of wall
It doesn't matter. eQUEST treats both the same. There are other infiltration calculation methods available in detail mode, but they are mostly for residential buildings, I think.
2-C. Does the baseline and purposed need to be the same?
It depends on what the energy model is intended to show. But in general, the weather file, occupancy schedules, building footprint and floor plans and process loads are kept the same.
2-D. Is there a set standard for the baseline?
Depends on what type of energy modeling you are doing. If it is for LEED, you must follow ASHRAE Standard 90.1 Appendix G. State incentive programs, utility programs and energy tax credit rules will all have different requirements for the baseline model. If you are trying to show energy savings of upgrades to an existing building, your baseline will be the current as-built design.
3. Thermostat.
(Positive note!! Instead of thinking of changing "night-time set back" values
as gaming, I should look at it as finding the best way to operate the system.
I think I am starting to understand!! If setting the thermostat back 10
degrees saves energy, I should do it! And the model shows me what to do!)
Sure, just be careful that the assumptions you are making are realistic.
3-A. Besides the owner's request are there any rules for thermostats?
Just to be careful. You may be able to model controls that are not really realistic. Such as having a very narrow deadband (difference between setpoints for heating and cooling mode) or temperatures that are controlled very precisely to within 0.5 deg.
3-B. Some have modeled heating only spaces as having a cooling system but
set the thermostat set point very high so it would not turn on. Is this an
acceptable method? (Example- I have a mechanical room which is
cooled by an exhaust fan when the temp is above 80 degrees, I modeled the
unit to turn on when the temp reached 95 degrees. The result it the cooling
never turns on, since the exhaust fan offers enough cooling.)
That is one way to do it. In rooms where the temperature is allowed to float, I remove the heating and/or cooling t-stat schedules entirely.
4. Odd rooms. It is easy to model office spaces, but I have found
electrical rooms, mechanical rooms, elevator equipment rooms, vestibules,
stairwells, and server rooms to be lacking on guidance.
4-A. Is there any resources besides general judgment?
I generally find these types of rooms fairly easy to model since they usually do not contain people for any significant amount of time. Ventilation or exhaust is determined by square footage. The hardest part is determining an appropriate receptacle load.
5. Minimal model. There is a lot of information which can be input.
Besides general gut feeling, how percise should the model be?
This again depends on the goals for the energy model.
5-1. If I leave all the thermostat "by zone", and don't actually model the
thermostat in the room is this okay?
It could be. Would all the rooms normally have individual thermostats? Are you grouping only similar rooms?
5-2. In an office, how do I schedule the meeting rooms? Do I show that the
population in the general office drops when everyone goes to the meeting?
Unless you have the building divided up into multiple shells, there is only one occupancy schedule that is the average for the entire building.
Very well put.
It's late on a Friday night, and watching TV is boring, so here are my thoughts on this topic/thread. I hope they are useful to somebody.
Way back in the email chain, somebody said that what they did in energy modeling had no effect on the construction drawings. That is a realistic result for some projects, but unfortunate. I share the frustration because I have worked on projects like that in the past. However, if we energy modelers are doing our jobs, we should be pushing the designers, and giving them feedback early on in the design process. But we have to step up and do that. We can't be a mouse and cannot just complain about the architect and engineering design team members not paying attention to the energy. Go educate them, & insert yourself in the design process. Give them the feedback that Karen has described. Measure your success not by how many LEED points the project earns, but by the fact that you helped the design team change something about the building so that it is more efficient in the real world (i.e. better wall insulation, better glass selection, better light fixtures, higher efficiency HVAC equipment, etc.). I like how somebody put it earlier in that energy modeling is for making decisions. If you helped the design team make some decisions, consider your effort a success. If your energy modeling resulted in nothing different in the construction documents, figure out why and fast because you are not adding value to the design process, which could be detrimental to your employment status. My personal opinion is that I do not think an energy modeling profession will survive solely to estimate LEED point for completed designs. If that is all we are doing, I think the building owners will figure out a way to eliminate us and our corresponding fees.
I think all energy modelers should read the document available from Energy Design Resources, called "Advanced Simulation Guidebook Volume II - The High Performance Building Process"
This document has some good thoughts regarding energy modeling and the design process.
This document correctly relays the fact that some kind of feedback early on in the design phase is a lot better than detailed modeling late in the game when the CD's are near 100% & little can be changed.
Don't get focused on making everything perfect or more detailed than it needs to be, especially if that is holding up getting decision making information to the design team. The thing about design teams is that they will make the decisions with or without you and move on to meet the deadline.
Finally, real buildings can and usually will operate far differently than our energy models suggest. If you really care about buildings using less energy, focus more on going into real buildings and helping the operators and owners figure out the best way to operate them to reduce energy. This gets into the M&V area, which I think all energy modelers should be focused on going forward because it can add real value. To that end, I will leave the group with one final bit of advice. Check out the Universal Translator freeware program available from the following website: http://utonline.org/cms/
I was very excited to find that this program existed because, in a nutshell, this program allows you to very easily work with real data from real building automation systems to figure out what the heck is going on in the buildings that are using too much energy. The UT program is developed by the Pacific Energy Center of PG&E.
Lots of good programs come out of California (which I'm very grateful for), like eQuest & now the Universal Translator. Add the UT to your toolkit. I think you will find the program to be very valuable.
That's my two cents! :)
Thanks!
Regards,
JAH
James A. Hess, PE, CEM
Does anyone have experience?on?creating an energy model?for an industrial facility to satisfy LEED?EAc1 and EAp2?
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ASHRAE 90.1.2007?says (2.Scope - page 4), you do not?need to follow 90.1?if it is?an industrial, manufaturing or commerical process facilities. Please share your experience on how to develop a baseline model.
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Regards,
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Senthil kumar a r