<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:12pt"><DIV>I did all that 30 years ago using the Meriwether ESAS program for Hilton Hotels. Before DOE-2. Before DOE-1 !!<BR></DIV>
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<B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> "Haynes, Glenn" <Glenn.Haynes@kema.com><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> Chris <chris@zed-uk.com>; backer@uidaho.edu; paul@zed-uk.com; thomasv@iit.edu<BR><B><SPAN style="FONT-WEIGHT: bold">Cc:</SPAN></B> bldg-sim@lists.onebuilding.org<BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Fri, May 21, 2010 8:22:53 AM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering<BR></FONT><BR>Chris,<BR><BR>You make a good point, and it also can apply to centrifugal chillers,<BR>which are sometimes most efficient at 60-80% loaded. But you still have<BR>to remember that the client has to pay for the larger equipment, which<BR>costs more, plus larger system components (which cost more) and more<BR>space (which costs more).<BR><BR>You also maake a good point about the system loads 90% of the time,<BR>which raises an interesting
question regarding sizing for optimum<BR>operating efficiency. What if we sized certain types of equipment to<BR>meet the most predominant loads within their most efficient capacity<BR>ranges? That is not difficult when using hourly simulation software.<BR>Of course, you have to keep an eye on peak loads and capacities. I<BR>haven't thought this through yet, but I'll bet someone else has.<BR><BR>Thanks,<BR>Glenn<BR><BR>-----Original Message-----<BR>From: "Chris" [mailto:<A href="mailto:chris@zed-uk.com" ymailto="mailto:chris@zed-uk.com">chris@zed-uk.com</A>] <BR>Sent: Thursday, May 20, 2010 7:13 PM<BR>To: Haynes, Glenn; <A href="mailto:backer@uidaho.edu" ymailto="mailto:backer@uidaho.edu">backer@uidaho.edu</A>; <A href="mailto:paul@zed-uk.com" ymailto="mailto:paul@zed-uk.com">paul@zed-uk.com</A>; <A href="mailto:thomasv@iit.edu" ymailto="mailto:thomasv@iit.edu">thomasv@iit.edu</A><BR>Cc: <A href="mailto:bldg-sim@lists.onebuilding.org"
ymailto="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</A><BR>Subject: Re: [Bldg-sim] Fwd: Re: RE: Voodoo Engineering<BR><BR>Glenn,<BR><BR>Oversize isn't always bad! A condensing boiler is generally at its most<BR>efficient at < 20% of its capacity.<BR><BR>All the same, the mid-season is largely ignored when it comes to sizing.<BR>Ridiculous really, when you think this is where the plant will be 90% of<BR>the time.<BR><BR>Perhaps this is more of an issue when you are shifting large amounts of<BR>chilled water to various pieces of zone equipment but has anybody<BR>considered Valve Authority? Unfortunately my experience is limited when<BR>it comes to the nitty gritty of piping networks. But, I do know one<BR>thing: valve response is not linear, especially if there is a<BR>substantial head in the system. My hunch is mid season control could get<BR>really messed up if plant has spare capacity but designers haven't been<BR>quite as
generous with pipe sizes.<BR><BR>Such questions should be in the domain of simulation in the next few<BR>years.<BR><BR>Chris<BR><BR>on 20/5/10 8:15 PM, "Haynes, Glenn" <<A href="mailto:Glenn.Haynes@kema.com" ymailto="mailto:Glenn.Haynes@kema.com">Glenn.Haynes@kema.com</A>> wrote:<BR><BR>> Brad,<BR>><BR>> I did HVAC design consulting for 14 years, and I used to oversize <BR>> systems just like everyone else. Now I am an energy conservation <BR>> programs evaluator, and have discovered the extent and negative <BR>> impacts of over sizing. Not speaking for all designers who oversize, <BR>> I did it mainly out of willful ignorance. It was easier for me to <BR>> loosely calculate the peak loads and then beef those estimates up <BR>> enough to safely cover and mistakes or false assumptions than it was <BR>> to calculate the loads with enough confidence to properly size the <BR>> systems. I
believed in the old adage that too much is just right from<BR><BR>> my perspective, because it minimized risk.<BR>><BR>> But now I have to measure the effects of excessive over sizing and see<BR><BR>> the results, some of which are poor humidity control, short cycling, <BR>> reduced system operating efficiency and higher first cost to the<BR>owner.<BR>> My DOE2 models usually indicate peak (I mean absolute hourly peak <BR>> loads) at about 20% less than Manual J loads, on average, for <BR>> residential applications. But even Manual J allows up to 20% above <BR>> their calculated loads, which have already been calculated using <BR>> conservative estimates for most inputs that are not explicitly <BR>> defined. The observed<BR>> (measured) field results have proven the average residential AC system<BR><BR>> to be about 70% to 75% oversized, with some as high as 200% (that's 3 <BR>> times the peak
load). 20% to 25% over ASHRAE's 2.5% design standard <BR>> is acceptable to me now, but anything above 25% without some <BR>> overriding owner requirement (plans to add on to the current building,<BR><BR>> etc.) begins to waste the owner's resources (from first cost to energy<BR><BR>> and maintenance costs) and reduce the lifetime of the equipment while <BR>> at the same time decreasing his overall level of comfort through <BR>> limited latent performance.<BR>><BR>> There! You obviously rubbed a sore spot in my emotional make-up, but <BR>> I appreciate the opportunity to make a point. And the point is this: <BR>> no matter how good your modeling software is, the outcome is still in <BR>> the hands of the user.<BR>><BR>> Glenn<BR>><BR>> -----Original Message-----<BR>> From: <A href="mailto:bldg-sim-bounces@lists.onebuilding.org"
ymailto="mailto:bldg-sim-bounces@lists.onebuilding.org">bldg-sim-bounces@lists.onebuilding.org</A><BR>> [mailto:<A href="mailto:bldg-sim-bounces@lists.onebuilding.org" ymailto="mailto:bldg-sim-bounces@lists.onebuilding.org">bldg-sim-bounces@lists.onebuilding.org</A>] On Behalf Of Acker, <BR>> Brad<BR>> Sent: Thursday, May 20, 2010 1:45 PM<BR>> To: Paul Carey; Chris Yates; Varkie C Thomas<BR>> Cc: <A href="mailto:bldg-sim@lists.onebuilding.org" ymailto="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</A><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><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 <BR>> part is what most bugs me. Why do people put so much effort into <BR>> models and then not use them to
size the systems? Preventing over <BR>> sizing is a great benefit of modeling. What is your experience with <BR>> using models to size systems? Why do engineers fall back on the vendor<BR><BR>> based programs and 9 out of 10 times end up over sizing systems?<BR>><BR>> Brad Acker, P.E.<BR>><BR>> -----Original Message-----<BR>> From: <A href="mailto:bldg-sim-bounces@lists.onebuilding.org" ymailto="mailto:bldg-sim-bounces@lists.onebuilding.org">bldg-sim-bounces@lists.onebuilding.org</A><BR>> [mailto:<A href="mailto:bldg-sim-bounces@lists.onebuilding.org" ymailto="mailto:bldg-sim-bounces@lists.onebuilding.org">bldg-sim-bounces@lists.onebuilding.org</A>] On Behalf Of Paul <BR>> Carey<BR>> Sent: Thursday, May 20, 2010 3:42 AM<BR>> To: 'Chris Yates'; 'Varkie C Thomas'<BR>> Cc: <A href="mailto:bldg-sim@lists.onebuilding.org" ymailto="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</A><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 <BR>> limits regarding energy modelling and its role in building regulation,<BR><BR>> we are seeing buildings that are being built and designed to purely <BR>> meet compliance. This is in some part is useful as it brings all <BR>> buildings up to a minimum standard, the flip side of that problem is <BR>> that it also means, that to many developers this means there is no <BR>> incentive to strive for alternatives or innovative solutions. It can <BR>> also allow therefore lead to the use of simpler tools that meet those <BR>> prescribed limits, but really don't push the boundaries of engineering<BR><BR>> design 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 <BR>> you consider the design process as a whole. If you use the tools at <BR>> the concept or schematic design phases, this can quantitatively <BR>> confirm an engineer's instinct or gained experience in way that will <BR>> enable them to show compliance later on. It will then allow the team <BR>> to come to a decision on the most energy efficient but also compliant <BR>> route of design earlier on in the design stage and should stop the <BR>> repeat iteration of designs as the building design progresses and <BR>> therefore reduce design costs and with luck increase productivity and<BR>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 <BR>> to do modelling, I know the principles of good low energy design, I <BR>> can read
books<BR>> and learn more if I need to". To which I replied, "Well every time<BR>you<BR>> send me a job to check for building regulation compliance 3 weeks <BR>> before it goes before a planning team, I normally have to tell you <BR>> what you need to do in terms of meeting compliance as your buildings <BR>> are consistently failing and you then have to rush to make those <BR>> changes. I am effectively designing your buildings for you, so if you<BR><BR>> want to continue without using energy modelling then please carry on, <BR>> and I'll 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>> -----Original Message-----<BR>> From: <A href="mailto:bldg-sim-bounces@lists.onebuilding.org"
ymailto="mailto:bldg-sim-bounces@lists.onebuilding.org">bldg-sim-bounces@lists.onebuilding.org</A><BR>> [mailto:<A href="mailto:bldg-sim-bounces@lists.onebuilding.org" ymailto="mailto:bldg-sim-bounces@lists.onebuilding.org">bldg-sim-bounces@lists.onebuilding.org</A>] On Behalf Of Chris <BR>> Yates<BR>> Sent: 20 May 2010 07:55<BR>> To: Varkie C Thomas<BR>> Cc: <A href="mailto:bldg-sim@lists.onebuilding.org" ymailto="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</A><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 <BR>> necessary 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 <<A href="mailto:thomasv@iit.edu" ymailto="mailto:thomasv@iit.edu">thomasv@iit.edu</A>> 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 <BR>>> response<BR>><BR>>> to John Eurek. Using energy programs is like voodoo engineering if <BR>>> 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 <<A href="mailto:elo@MichaelsEngineering.com"
ymailto="mailto:elo@MichaelsEngineering.com">elo@MichaelsEngineering.com</A>><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 <BR>>>> 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 [mailto:<A href="mailto:John.S.Eurek@usace.army.mil" ymailto="mailto:John.S.Eurek@usace.army.mil">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; <A href="mailto:cmg750@gmail.com" ymailto="mailto:cmg750@gmail.com">cmg750@gmail.com</A><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><BR>>>> not used to generate construction drawings." This may be my #1 beef<BR><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 [mailto:<A href="mailto:thomasv@iit.edu" ymailto="mailto:thomasv@iit.edu">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><BR>>>> have not dealt withreal buildings. Attached are my views on energy <BR>>>> modeling.<BR>>>><BR>>>> ----- Original Message -----<BR>>>> From: "Eurek, John S NWO" <<A href="mailto:John.S.Eurek@usace.army.mil" ymailto="mailto:John.S.Eurek@usace.army.mil">John.S.Eurek@usace.army.mil</A>><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: <A href="mailto:equest-users-bounces@lists.onebuilding.org" ymailto="mailto:equest-users-bounces@lists.onebuilding.org">equest-users-bounces@lists.onebuilding.org</A><BR>>>>> [mailto:<A href="mailto:equest-users-bounces@lists.onebuilding.org" ymailto="mailto:equest-users-bounces@lists.onebuilding.org">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: <A
href="mailto:equest-users@lists.onebuilding.org" ymailto="mailto:equest-users@lists.onebuilding.org">equest-users@lists.onebuilding.org</A>; <A href="mailto:curt.strobehn@eesinet.com" ymailto="mailto:curt.strobehn@eesinet.com">curt.strobehn@eesinet.com</A><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>>> _______________________________________________<BR>>> Bldg-sim mailing list<BR>>> <A href="http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org" target=_blank>http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org</A><BR>>> To unsubscribe from this mailing list send a blank message to<BR>> <A href="mailto:BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG"
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