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<P><FONT SIZE=2>As a designer of geothermal hvac systems I found this very relevant. For vertical closed loop systems you buy by the foot. Over design of 5 or 10 percent adds that much cost and effects the return on investment for the client. The ground loop is sized based on monthy peak and total loads.<BR>
<BR>
Steve DiBerardine PE CGD LEED AP<BR>
Strategic Energy Solutions<BR>
steved@sesnet.com<BR>
<BR>
<BR>
-----Original Message-----<BR>
From: Haynes, Glenn [<A HREF="mailto:Glenn.Haynes@kema.com">mailto:Glenn.Haynes@kema.com</A>]<BR>
Sent: Thursday, May 20, 2010 06:57 PM Eastern Standard Time<BR>
To: ssavich@systemswestengineers.com; Eurek, John S NWO; bldg-sim@lists.onebuilding.org<BR>
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering<BR>
<BR>
The difference between using equipment sizing software and hourly<BR>
building energy simulation software is interpretation of the peak loads.<BR>
The equipment sizing software utilizes a worst case scenario of load<BR>
contributing conditions to size the equipment and yields an appropriate<BR>
peak system load up front - no need to beef it up except to cover errors<BR>
or extenuating circumstances.<BR>
<BR>
A building energy simulation code yields the peak loads under the most<BR>
probable conjunction of extreme conditions, so you should beef those up<BR>
by some reasonable factor if you need to guarantee enough capacity under<BR>
the most extreme combination of factors.<BR>
<BR>
Either way, you should end up with approximately the same system size<BR>
without unnecessary over sizing. But if you beef up the equipment<BR>
sizing software results without proper justification, and then select<BR>
the next higher modular equipment size, you will probably end up with an<BR>
unnecessarily oversized system; a low personal risk approach, but not<BR>
the best design choice for the client who has to pay for it and live<BR>
with it.<BR>
<BR>
Glenn<BR>
<BR>
-----Original Message-----<BR>
From: bldg-sim-bounces@lists.onebuilding.org<BR>
[<A HREF="mailto:bldg-sim-bounces@lists.onebuilding.org">mailto:bldg-sim-bounces@lists.onebuilding.org</A>] On Behalf Of Steven<BR>
Savich<BR>
Sent: Thursday, May 20, 2010 2:12 PM<BR>
To: 'Eurek, John S NWO'; bldg-sim@lists.onebuilding.org<BR>
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering<BR>
<BR>
John,<BR>
<BR>
Using energy modeling programs for sizing is another topic that we'll<BR>
find a lot of people on the list disagreeing about.<BR>
<BR>
Really, Trane Trace and Carrier HAP are equipment sizing programs that<BR>
also do energy modeling.<BR>
<BR>
eQuest/DOE 2.2 (the program I am most familiar with) also has the option<BR>
of setting design day schedules, and will give you reports that show<BR>
peak Heating and Cooling loads. With sound engineering judgment, a<BR>
thorough understanding of the modeling program you're using, and careful<BR>
checking of your results, I believe that you can use many hourly<BR>
modeling programs to size your equipment, or at least to provide a<BR>
"second opinion" about the results from your primary sizing program.<BR>
<BR>
<BR>
Steven<BR>
<BR>
<BR>
<BR>
-----Original Message-----<BR>
From: bldg-sim-bounces@lists.onebuilding.org<BR>
[<A HREF="mailto:bldg-sim-bounces@lists.onebuilding.org">mailto:bldg-sim-bounces@lists.onebuilding.org</A>] On Behalf Of Eurek, John<BR>
S NWO<BR>
Sent: Thursday, May 20, 2010 10:59 AM<BR>
To: bldg-sim@lists.onebuilding.org<BR>
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering<BR>
<BR>
Brad,<BR>
<BR>
Using energy modeling for system sizing would be a misuse of a<BR>
tool.<BR>
<BR>
The energy model uses average temperatures, design uses extreme<BR>
temperatures. <BR>
<BR>
Another example would be a classroom which can hold up to 40<BR>
people.<BR>
Actual use is estimated at 25 people, but owner would like to be able to<BR>
have 40 people. The model would use 25 people (actual use) but the<BR>
designer would size equipment for 40 people (worst case).<BR>
<BR>
Also, energy models get to count rejected heat from office<BR>
equipment and people. When sizing equipment you can not count the<BR>
lighting, office equipment and people heat to assist in heating.<BR>
<BR>
There is more CYA in equipment sizing. There is more liability.<BR>
<BR>
<BR>
-----Original Message-----<BR>
From: bldg-sim-bounces@lists.onebuilding.org<BR>
[<A HREF="mailto:bldg-sim-bounces@lists.onebuilding.org">mailto:bldg-sim-bounces@lists.onebuilding.org</A>] On Behalf Of Acker, Brad<BR>
Sent: Thursday, May 20, 2010 12:45 PM<BR>
To: Paul Carey; Chris Yates; Varkie C Thomas<BR>
Cc: bldg-sim@lists.onebuilding.org<BR>
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering<BR>
<BR>
I do not do modeling on a daily basis so I'm not as experience as many<BR>
other here. I do agree modeling just for LEED is silly. I have seen<BR>
modeling inform designs, reduce loads, and SIZE SYSTEMS. This last part<BR>
is what most bugs me.<BR>
Why do people put so much effort into models and then not use them to<BR>
size the systems? Preventing over sizing is a great benefit of modeling.<BR>
What is your experience with using models to size systems? Why do<BR>
engineers fall back on the vendor based programs and 9 out of 10 times<BR>
end up over sizing systems?<BR>
<BR>
Brad Acker, P.E.<BR>
<BR>
-----Original Message-----<BR>
From: bldg-sim-bounces@lists.onebuilding.org<BR>
[<A HREF="mailto:bldg-sim-bounces@lists.onebuilding.org">mailto:bldg-sim-bounces@lists.onebuilding.org</A>] On Behalf Of Paul Carey<BR>
Sent: Thursday, May 20, 2010 3:42 AM<BR>
To: 'Chris Yates'; 'Varkie C Thomas'<BR>
Cc: bldg-sim@lists.onebuilding.org<BR>
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering<BR>
<BR>
Just to add a couple of points to this interesting debate.<BR>
<BR>
I see the problem being that, as we increasingly set more defined limits<BR>
regarding energy modelling and its role in building regulation, we are<BR>
seeing buildings that are being built and designed to purely meet<BR>
compliance. This is in some part is useful as it brings all buildings<BR>
up to a minimum standard, the flip side of that problem is that it also<BR>
means, that to many developers this means there is no incentive to<BR>
strive for alternatives or innovative solutions. It can also allow<BR>
therefore lead to the use of simpler tools that meet those prescribed<BR>
limits, but really don't push the boundaries of engineering design<BR>
enhancement of buildings.<BR>
<BR>
The correct implementation and use of energy modelling need not be a<BR>
hindrance to projects nor be seen as a necessary "extra" or evil if you<BR>
consider the design process as a whole. If you use the tools at the<BR>
concept or schematic design phases, this can quantitatively confirm an<BR>
engineer's instinct or gained experience in way that will enable them to<BR>
show compliance later on. It will then allow the team to come to a<BR>
decision on the most energy efficient but also compliant route of design<BR>
earlier on in the design stage and should stop the repeat iteration of<BR>
designs as the building design progresses and therefore reduce design<BR>
costs and with luck increase productivity and profit accordingly.<BR>
Fanciful dream perhaps, but it does work.<BR>
<BR>
I visited an architect a while back and he said to me "Why do I need to<BR>
do modelling, I know the principles of good low energy design, I can<BR>
read books<BR>
and learn more if I need to". To which I replied, "Well every time you<BR>
send me a job to check for building regulation compliance 3 weeks before<BR>
it goes before a planning team, I normally have to tell you what you<BR>
need to do in terms of meeting compliance as your buildings are<BR>
consistently failing and you then have to rush to make those changes. I<BR>
am effectively designing your buildings for you, so if you want to<BR>
continue without using energy modelling then please carry on, and I'll<BR>
continue to design your buildings."<BR>
As you can imagine this was one of those Eureka moments for this<BR>
Architect, as I waved my red rag in front of his face.<BR>
<BR>
My tuppence worth.<BR>
<BR>
Paul<BR>
<BR>
<BR>
<BR>
<BR>
<BR>
-----Original Message-----<BR>
From: bldg-sim-bounces@lists.onebuilding.org<BR>
[<A HREF="mailto:bldg-sim-bounces@lists.onebuilding.org">mailto:bldg-sim-bounces@lists.onebuilding.org</A>] On Behalf Of Chris Yates<BR>
Sent: 20 May 2010 07:55<BR>
To: Varkie C Thomas<BR>
Cc: bldg-sim@lists.onebuilding.org<BR>
Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering<BR>
<BR>
Varkie<BR>
<BR>
Vast subject. Kudos for condensing it whilst conveying all the necessary<BR>
meaning.<BR>
<BR>
We are now at a point where Energy Modellers are at the very least<BR>
specialist engineers. In fact, you could say the best are indeed<BR>
"wizards"!<BR>
<BR>
Chris<BR>
<BR>
Sent from my iPhone<BR>
<BR>
On 19 May 2010, at 21:35, Varkie C Thomas <thomasv@iit.edu> wrote:<BR>
<BR>
> Since my response has ended up on Bldg-Sim, I might as well include<BR>
> the attachment with the response which gave my views<BR>
> <Building-Energy-Programs-VCT.doc><BR>
> I am including the attachment that I included with my earlier response<BR>
<BR>
> to John Eurek. Using energy programs is like voodoo engineering if you<BR>
<BR>
> don't understand its engineering basis. It analyzes the various<BR>
> options quantitatively. It cannot be used as a magic black box.<BR>
> Experience and judgement have to applied to the results.<BR>
><BR>
> ----- Original Message -----<BR>
> From: Eric O'Neill <elo@MichaelsEngineering.com><BR>
> Date: Wednesday, May 19, 2010 12:03 pm<BR>
> Subject: RE: Voodoo Engineering<BR>
><BR>
>> John,<BR>
>><BR>
>> The purpose of energy modeling is to identify differences between two<BR>
<BR>
>> energy related setups. The idea is to tell you how much you could<BR>
>> conceivably save by switching from one design to another. This is<BR>
>> usefulfor a payback analysis or life cycle cost analysis.<BR>
>><BR>
>> Hope this helps, (I'm really not trying to be inflammatory :) )<BR>
>><BR>
>> Eric<BR>
>><BR>
>> -----Original Message-----<BR>
>> From: Eurek, John S NWO [<A HREF="mailto:John.S.Eurek@usace.army.mil">mailto:John.S.Eurek@usace.army.mil</A>]<BR>
>> Sent: Wednesday, May 19, 2010 11:19 AM<BR>
>> To: Varkie C Thomas<BR>
>> Cc: Eric O'Neill; cmg750@gmail.com<BR>
>> Subject: RE: Voodoo Engineering<BR>
>><BR>
>> Varkie, I read your attached paper.<BR>
>><BR>
>> "Energy programs are external to the design process. The results are<BR>
>> not used to generate construction drawings." This may be my #1 beef<BR>
>> with energymodeling. What is the purpose?<BR>
>><BR>
>> If you say, to save energy... It does not.<BR>
>><BR>
>><BR>
>> John Eurek<BR>
>> LEEP AP<BR>
>><BR>
>><BR>
>> -----Original Message-----<BR>
>> From: Varkie C Thomas [<A HREF="mailto:thomasv@iit.edu">mailto:thomasv@iit.edu</A>]<BR>
>> Sent: Wednesday, May 19, 2010 10:08 AM<BR>
>> To: Eurek, John S NWO<BR>
>> Subject: Voodoo Engineering<BR>
>><BR>
>> Academia institutions and research centers tend to attach<BR>
>> disproportionate amount of importance to energy modeling. Most them<BR>
>> have not dealt withreal buildings. Attached are my views on energy<BR>
>> modeling.<BR>
>><BR>
>> ----- Original Message -----<BR>
>> From: "Eurek, John S NWO" <John.S.Eurek@usace.army.mil><BR>
>> Date: Wednesday, May 19, 2010 8:14 am<BR>
>> Subject: Re: [Equest-users] Compliance rule set for Oregon<BR>
>><BR>
>>><BR>
>>> I would prefer Lynn work to ban/destroy/do-away-with energy<BR>
>> modeling.><BR>
>>> Any chance this voo-doo engineering will go away any time soon?<BR>
>>> It is only<BR>
>>> statistical analysis with no meaningful/useful results for anyone.<BR>
>>><BR>
>>> As a community I think we are going in the wrong direction for<BR>
>> the<BR>
>>> rightgoals.<BR>
>>><BR>
>>> -----Original Message-----<BR>
>>> From: equest-users-bounces@lists.onebuilding.org<BR>
>>> [<A HREF="mailto:equest-users-bounces@lists.onebuilding.org">mailto:equest-users-bounces@lists.onebuilding.org</A>] On Behalf Of<BR>
>> Carol<BR>
>>> Gardner<BR>
>>> Sent: Wednesday, May 19, 2010 12:30 AM<BR>
>>> To: Scott Criswell<BR>
>>> Cc: equest-users@lists.onebuilding.org; curt.strobehn@eesinet.com<BR>
>>> Subject: Re: [Equest-users] Compliance rule set for Oregon<BR>
>>><BR>
>>> All,<BR>
>>><BR>
>>> Lynn Bellenger will soon be the first female president of ASHRAE..<BR>
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