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<DIV>I really must take some exception to your dismissal of using DOE2 to
calculate energy savings. After all, what do you think people use DOE2, or
any other energy simulation program, for?</DIV>
<DIV> </DIV>
<DIV>We have done far more projects using DOE2 to estimate energy savings than I
care to think about. The answers produced by the analysis must be taken
with some caveats, but in general, they are the best available estimate of
savings reasonably attainable. Part of what you are getting at, I believe,
it the fact that people's behavior on an individual scale is unknowable and that
generalized answers do not necessarily apply to specific cases.</DIV>
<DIV> </DIV>
<DIV>In a commercial building this may manifest itself in the fact that part of
a building is unexpectedly unoccupied, or that the facilities guy stuck a 2x4 in
the outside air damper to get rid of "that stink in suite 302". If you did
not anticipate these factors, then of course the energy prediction will be
less accurate. On the other hand, if you could predict these factors, then
DOE2 would have no problem accounting for them. If you want to conduct an
energy savings analysis for a specific building, an audit is really
required. If you enter an accurate description of the building and its
operation, then DOE2 does an extremely good job of predicting its energy
use. And that is what DOE2 is intended to do. It, of course, cannot
predict deviant and unexpected behavior in the building operation on
it's own ... the person modeling the building must do this.</DIV>
<DIV> </DIV>
<DIV>If you apply savings analysis for a "typical" small office to a specific
building operating under specific conditions, then yes, there is and should be
significantly less confidence in the answer. This is an issue for the
analysis itself, and is not a limitation of the analysis tool.</DIV>
<DIV> </DIV>
<DIV>In residential buildings, this phenomena is even more evident. We
have used DOE2.2 to predict the energy flows of residential homes throughout the
U.S.. These houses were operated under test conditions, and actual energy flows
were measured using co-heating and co-cooling techniques. The test
protocol included adding/removing window shades, decreasing/increasing duct
loss, increasing/decreasing ventilation rates, etc.. Time after time, the
analysis using DOE2 was able to predict the hourly energy flows of these houses
within a very small error band (on the order of 1 or 2 percent). This
required a detailed model, including all the site and self shading for that
individual house. But given detailed and correct inputs, DOE2 has no
problem predicting accurate hourly energy use.</DIV>
<DIV> </DIV>
<DIV>Now, add real people to these houses and all bets are off! It is
impossible to predict the individual behavior of people. Just think, 20
years ago there were two popular singers, the wholesome Michael Jackson and the
apparently perverse "Prince". Who could have predicted that Prince would
turn out to be the straight family guy and the other one would become ... well,
"Michael Jackson". Put both these guys in a house and try and predict the
energy use ... no way! Luckily, group behavior is much easier to predict
and estimates of typical energy use are possible, even for residential
buildings.</DIV>
<DIV> </DIV>
<DIV>We've been using DOE2.2 for a couple years now, and I encourage anyone
using DOE2.1 on a regular basis to check it out. The systems/plant is much
more flexible now and organized in a far more logical way. On the loads
side, the use of polygons to describe spaces makes detailed models far easier
(it took me awhile to realize the advantages of this approach, but once I made
the switch the time savings became very evident). The addition of "expressions"
to the BDL language makes for the possibility of some extremely "smart" BDL
code. Okay okay, the possibility still exists of producing BDL code that
thinks it's really smart, but really has a 2x4 stuck in the wrong
place.</DIV>
<DIV> </DIV>
<DIV>Paul Reeves</DIV>
<DIV>
<DIV>The Partnership for Resource Conservation<BR>140 South 34th Street,
Boulder, CO 80303<BR>(303) 499-8611 </DIV>
<DIV> </DIV>
<DIV>----- Original Message ----- </DIV></DIV></DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A href="mailto:David.Chassin@pnl.gov" title=David.Chassin@pnl.gov>Chassin,
David P</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A href="mailto:BLDG-SIM@gard.com"
title=BLDG-SIM@gard.com>BLDG-SIM@gard.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, January 28, 2000 11:28
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [BLDG-SIM] hornets nest? Stay
the course !!</DIV>
<DIV><BR></DIV>"And for the retrofit industry, I STILL gotta match the utitliy
meters...."<BR>I don't think we have any hope of ever achieving that with
today's tools (or<BR>even those that are in the works). Our simulation
tools can't simulate *all*<BR>the stupid mistakes and failures that are made
in building design, construction,<BR>and operation. The only time you'll
get your output to match the utility meter<BR>is if you tweek something else
that probably has nothing to do with reality.<BR>This is just one of the
things that give me pause when people talk about using<BR>DOE-2 (or any other
engine in existence) to simulate buildings in order to<BR>estimate
savings. We *know* the model is wrong because it can't simulate a
2x4<BR>stuck in the makeup vane of an economizer by a frustrated operator
trying to get<BR>some fresh air in a building with a messed up economizer
control he can't figure<BR>out. These kind of things happen all the
time.<BR>Dave<BR><BR>David P. Chassin<BR>Staff Scientist<BR>Pacific Northwest
National Laboratory<BR>Richland, Washington<BR>509-375-4369<BR><A
href="mailto:david.chassin@pnl.gov">david.chassin@pnl.gov</A> <<A
href="mailto:david.chassin@pnl.gov">mailto:david.chassin@pnl.gov</A>>
<BR><BR>Disclaimer: The facts above are based on memory proven faulty on
numerous<BR>occasions, and the opinions are not those of my employer or its
clients even<BR>though I sometimes wish they were.<BR><BR><BR>-----Original
Message-----<BR>From: John Aulbach [<A
href="mailto:SMTP:jaulbach@sna.sempra-esco.com">SMTP:jaulbach@sna.sempra-esco.com</A>]<BR>Sent:
Thursday, January 27, 2000 14:09<BR>To: <A
href="mailto:BLDG-SIM@gard.com">BLDG-SIM@gard.com</A><BR>Subject: [BLDG-SIM]
hornets nest? Stay the course !!<BR><BR>[snip]<BR><BR>And for the retrofit
industry, I STILL gotta match the
utitliy<BR>meters....<BR><BR><BR><BR>======================================================<BR>You
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