[Bldg-sim] Fwd: Re: RE: Voodoo Engineering

Fri May 21 12:15:50 PDT 2010

John,

If this is the procedure you're following for modeling in TRACE, I can see why you view modeling as a pain in the arse. With proper use of schedules, day types, and diversity, what you've described below is easily accomplished in one alternative in one file. I highly suggest attending one of several of our training sessions held throughout the year.

http://www.trane.com/Commercial/Dna/View.aspx?i=708

Scott Hintz
Trane C.D.S.
(608) 787-3926

-----Original Message-----
From: Eurek, John S NWO [mailto:John.S.Eurek at usace.army.mil]
Sent: Thursday, May 20, 2010 2:09 PM
To: MAWK (Matthew Kimball); bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering

Matt,

I use trace for Sizing and energy modeling.  But I have 3 different files.

1.  Equipment sizing - This has the max number of people ever expected in the
building. So if it was a school I don't count a child in the classroom and
the lunch room (he is either in one place or the other).  I set the lights
and people to be cooling only.  This is used to size chillers, boilers, the
other plants.

2.  System sizing -  I call this a butt in every seat. This has the max
number of people in each zone. I use this to size VAV boxes and other zone
equipment.  The number of people is larger than reality.

3.  Energy Model - This has schedule, the office equipment schedules (heat
rejection counts), I input data about equipment performance, drift points....
Well you know about energy modeling.

What you can't do is print out your enegy model and try to use the results to
size equipment. (from what I understand)

I use the same program, same construction, same temperature setting but each
file has a different intent.  I change the weather from 99.5% to the 8760, I
change the number of people from worst case, to actual.

There many be other methods, but this is how I do it.

-----Original Message-----
From: MAWK (Matthew Kimball) [mailto:MAWK at nnepharmaplan.com]
Sent: Thursday, May 20, 2010 1:45 PM
To: Eurek, John S NWO; bldg-sim at lists.onebuilding.org
Subject: RE: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering

So let me ask you John,

How do you find peak heating and cooling loads without using a modeling
program such as HAP or Trane Trace to take into account equipment loads and
solar heating loads?  Of course you can't use equipment loads to find peak
heating load, but you can use them to find peak cooling loads.  Do you only
size heating equipment?  And don't you realize that modeling software can be
changed for different occupation conditions?  If you are using effective
modeling software, there are a multitude of factors and situations that are
taken into account.  Its not the software itself that is effective, it is the
person who is using it intelligently ; )

Matthew Kimball
AutoCAD Developer, Process & Mechanical

NNE Pharmaplan

mawk at nnepharmaplan.com    www.nnepharmaplan.com

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-----Original Message-----
From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Eurek, John S
NWO
Sent: Thursday, May 20, 2010 1:59 PM
To: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering

Brad,

        Using energy modeling for system sizing would be a misuse of a tool.

        The energy model uses average temperatures, design uses extreme
temperatures.

        Another example would be a classroom which can hold up to 40 people.
Actual use is estimated at 25 people, but owner would like to be able to have
40 people.  The model would use 25 people (actual use) but the designer would
size equipment for 40 people (worst case).

        Also, energy models get to count rejected heat from office equipment
and people.  When sizing equipment you can not count the lighting, office
equipment and people heat to assist in heating.

        There is more CYA in equipment sizing.  There is more liability.

-----Original Message-----
From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Acker, Brad
Sent: Thursday, May 20, 2010 12:45 PM
To: Paul Carey; Chris Yates; Varkie C Thomas
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering

I do not do modeling on a daily basis so I'm not as experience as many other
here. I do agree modeling just for LEED is silly. I have seen modeling inform
designs, reduce loads, and SIZE SYSTEMS. This last part is what most bugs me.
Why do people put so much effort into models and then not use them to size
the systems? Preventing over sizing is a great benefit of modeling. What is
your experience with using models to size systems? Why do engineers fall back
on the vendor based programs and 9 out of 10 times end up over sizing
systems?

Brad Acker, P.E.

-----Original Message-----
From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Paul Carey
Sent: Thursday, May 20, 2010 3:42 AM
To: 'Chris Yates'; 'Varkie C Thomas'
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering

Just to add a couple of points to this interesting debate.

I see the problem being that, as we increasingly set more defined limits
regarding energy modelling and its role in building regulation, we are seeing
buildings that are being built and designed to purely meet compliance.  This
is in some part is useful as it brings all buildings up to a minimum
standard, the flip side of that problem is that it also means, that to many
developers this means there is no incentive to strive for alternatives or
innovative solutions.  It can also allow therefore lead to the use of simpler
tools that meet those prescribed limits, but really don't push the boundaries
of engineering design enhancement of buildings.

The correct implementation and use of energy modelling need not be a
hindrance to projects nor be seen as a necessary "extra" or evil if you
consider the design process as a whole.  If you use the tools at the concept
or schematic design phases, this can quantitatively confirm an engineer's
instinct or gained experience in way that will enable them to show compliance
later on. It will then allow the team to come to a decision on the most
energy efficient but also compliant route of design earlier on in the design
stage and should stop the repeat iteration of designs as the building design
progresses and therefore reduce design costs and with luck increase
productivity and profit accordingly.  Fanciful dream perhaps, but it does
work.

I visited an architect a while back and he said to me "Why do I need to do
modelling, I know the principles of good low energy design, I can read books
and learn more if I need to".   To which I replied, "Well every time you
send me a job to check for building regulation compliance 3 weeks before it
goes before a planning team, I normally have to tell you what you need to do
in terms of meeting compliance as your buildings are consistently failing and
you then have to rush to make those changes.  I am effectively designing your
buildings for you, so if you want to continue without using energy modelling
then please carry on, and I'll continue to design your buildings."
As you can imagine this was one of those Eureka moments for this Architect,
as I waved my red rag in front of his face.

My tuppence worth.

Paul

-----Original Message-----
From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Chris Yates
Sent: 20 May 2010 07:55
To: Varkie C Thomas
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering

Varkie

Vast subject. Kudos for condensing it whilst conveying all the necessary
meaning.

We are now at a point where Energy Modellers are at the very least specialist
engineers. In fact, you could say the best are indeed "wizards"!

Chris

Sent from my iPhone

On 19 May 2010, at 21:35, Varkie C Thomas <thomasv at iit.edu> wrote:

> Since my response has ended up on Bldg-Sim, I might as well include
> the attachment with the response which gave my views
> <Building-Energy-Programs-VCT.doc>
> I am including the attachment that I included with my earlier response
> to John Eurek. Using energy programs is like voodoo engineering if you
> don't understand its engineering basis.  It analyzes the various
> options quantitatively.  It cannot be used as a magic black box.
> Experience and judgement have to applied to the results.
>
> ----- Original Message -----
> From: Eric O'Neill <elo at MichaelsEngineering.com>
> Date: Wednesday, May 19, 2010 12:03 pm
> Subject: RE: Voodoo Engineering
>
>> John,
>>
>> The purpose of energy modeling is to identify differences between two
>> energy related setups. The idea is to tell you how much you could
>> conceivably save by switching from one design to another. This is
>> usefulfor a payback analysis or life cycle cost analysis.
>>
>> Hope this helps, (I'm really not trying to be inflammatory :) )
>>
>> Eric
>>
>> -----Original Message-----
>> From: Eurek, John S NWO [mailto:John.S.Eurek at usace.army.mil]
>> Sent: Wednesday, May 19, 2010 11:19 AM
>> To: Varkie C Thomas
>> Cc: Eric O'Neill; cmg750 at gmail.com
>> Subject: RE: Voodoo Engineering
>>
>> Varkie, I read your attached paper.
>>
>> "Energy programs are external to the design process. The results are
>> not used to generate construction drawings."  This may be my #1 beef
>> with energymodeling.  What is the purpose?
>>
>> If you say, to save energy...  It does not.
>>
>>
>> John Eurek
>> LEEP AP
>>
>>
>> -----Original Message-----
>> From: Varkie C Thomas [mailto:thomasv at iit.edu]
>> Sent: Wednesday, May 19, 2010 10:08 AM
>> To: Eurek, John S NWO
>> Subject: Voodoo Engineering
>>
>> Academia institutions and research centers tend to attach
>> disproportionate amount of importance to energy modeling.  Most them
>> have not dealt withreal buildings.  Attached are my views on energy
>> modeling.
>>
>> ----- Original Message -----
>> From: "Eurek, John S NWO" <John.S.Eurek at usace.army.mil>
>> Date: Wednesday, May 19, 2010 8:14 am
>> Subject: Re: [Equest-users] Compliance rule set for Oregon
>>
>>>
>>> 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
>>> rightgoals.
>>>
>>> -----Original Message-----
>>> From: equest-users-bounces at lists.onebuilding.org
>>> [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of
>> Carol
>>> Gardner
>>> Sent: Wednesday, May 19, 2010 12:30 AM
>>> To: Scott Criswell
>>> Cc: equest-users at lists.onebuilding.org; curt.strobehn at eesinet.com
>>> Subject: Re: [Equest-users] Compliance rule set for Oregon
>>>
>>> All,
>>>
>>> Lynn Bellenger will soon be the first female president of ASHRAE..
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