[BLDG-SIM] Weather Normalization Question

[Douglas Mahone]

To calibrate models to reality, you must also watch out for what's
included in the utility bills. In the real world of utility billing
meters, there can be other extraneous energy users attached that your
model may not know about.  Things like escalators, outdoor lighting,
pool pumps, outbuildings, even parts of neighboring tenants' spaces.

And, of course, there's the difference between how equipment is supposed
to operate and how it actually operates (going beyond the "unique
operating strategies" that Michael mentions).  Sometimes equipment is
plain broken and not drawing any energy, or else it's failed in such a
way that it's drawing a lot more energy, such an an economizer damper
failed open.

Calibrating models entails either incredibly detailed investigation of
the actual building, or else application of the black art of making
informed guesses ("engineering judgment").  In our experience, there's a
significant portion of models that just won't calibrate, because the
actual energy use is too strange and resources to investigate why are
not infinite.

The real objective of generating reasonable energy savings estimates,
however, can still be met if the model is overall reasonable.  It's the
delta in energy use attributable to the efficiency measures of interests
that matter, not necessarily tracking down all the unusual quirks of
utility metering and billing systems.  In the old days, we just
calculated the expected savings of an individual measure and ignored the
rest of the building.  Using a whole building simulation can be a big
improvement on that practice.

Good luck.


Douglas Mahone, Principal
Heschong Mahone Group, Inc.
11626 Fair Oaks Blvd. #302
Fair Oaks, CA  95628

(916) 962-7001
fax (916) 962-0101
dmahone at h-m-g.com

web site: www.h-m-g.com


-----Original Message-----
From: Michael Wilson [mailto:mwilsonbc at yahoo.com] 
Sent: Monday, March 10, 2003 3:38 PM
To: BLDG-SIM at GARD.COM
Subject: [BLDG-SIM] Weather Normalization Question


Hi, I've done a few calibrations to bills, and that's
how I've done it. I order up a years worth of weather
data for the most recent year and convert it to Doe2
format. But you also need to adjust your bills in
Excel if they don't end on the 31st of the month. This
can cause some problems if they're off by quite a bit,
ie. end on the 15th. 

Also I find you need to be careful with calibrations,
as real buildings often have interesting and unique
operating strategies not modelled well by Doe2. Check
carefully how the building controls are working.


--- Andrew Holden <andrew at heliosltd.com> wrote:
> Hi bldg-sims: 
> 
> After using DOE modeling tools intermittently now
> for many years I am now using eQuest and one of its
> cousins in earnest.  After reading the manuals a
> couple of things still are not totally evident.
> 
> I would like to synchronize the eQuest modeled
> behavior to the actual utility bills for a given
> calendar year (so I know I modeled it properly),
> then apply the 30 year average data to tell me how
> the building should perform going forwards in a
> baseline mode and after EEMs are applied.
> 
> Am I correct that the only way to do that is to take
> real weather data from say 2002, use some of the
> weather utility applications to create a suitable
> packed format for the DOE-2 engine, run that, make
> sure it is calibrated properly, then switch the
> weather data to 30-year data and re-run it.  
> 
> Do most of you seasoned modelers keep two sets of
> all your weather data laying around, DOE-2 packed
> actual yearly data plus the 30 year formats?  Or
> isn't it worth it?
> 
> Also, can I input actual bill histories into eQuest
> to compare modeled versus actual bills?
> 
> Any suggestions would greatly be appreciated.
> 
> Thanks,
> 
> Andrew Holden, CEM, LEED
> Helios Resources, Ltd.
> 1883 Old Kimberton Road
> Phoenixville, PA 19460
> Tel: 610-917-9111
> Fax: 610-917-1066
> Cell: 484-437-3754
> http://www.heliosltd.com
> "Nothing astonishes men so much as common sense and
> plain dealing." - Ralph Waldo Emerson, 1803-1882
> 
> 
> 
>
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=====
Michael Wilson
455 Elphinstone Ave.
Gibsons, BC, V0N 1V1
604-886-9864 phone
604-676-2604 fax

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