[Bldg-sim] Modelling for retrofit ECM's

[Jeff Haberl]

ONE MORE...



BTW, there's one more paper that is worth point out because it is one of the first articles that I recall that pointed to the fact that the "final" values for a simulation input parameters may have little to do with the nominal values that are first observed and entered. That paper was presented at the 1996 ASME conference in San Antonio, TX.



The citation is:



Manke, J., Hittle, D. and Hancock, C., 1996. "Calibration Building Energy Analysis Models Using Short-term Test Data", Proceedings of the 1996 ASME Solar Energy Conference, p. 369, San Antonio, TX.



This study reviewed a conference center in Gunnison, CO, using BLAST, and another buidling. In this paper they showed that strange things happen when you do a "blind" best fit for various parameters. However, at the end of the effort, they had a much improved fit of the simulation output to the measured data. For example, such things as the UA of a wall or floor might actually give better simulation results if it was 10, 100 or 1000x what the nominal value was. In general, they use a 0.1x to 10x approach to systematically explore different variables until they got the best fit to some short term data.



So, the point of bringing this into the ongoing discussion, is that when a simulator is "fitting" a simulation to measured data, hopefully some short-term measured data, don't be surprised if the "final" values of the parameters are totally unrealistic as this may be indicating a physical characteristic that is not being well represented by the model (i.e., an interior convection coefficient), and in fact is better modeled when the input parameter is completely "empirical", sometimes being 0.01x, 0.1x, 1x, 10x, 100x or 1000x the known value. Weird stuff indeed, but worth keeping in the back of you mind as you calibrate your simulation!



Jeff



8=!  8=)  :=)  8=)  ;=)  8=)  8=(  8=)  8=()  8=)  8=|  8=)  :=')  8=)8=?

Jeff S. Haberl, Ph.D.,P.E., FASHRAE..............jhaberl at tamu.edu

Professor............................................................Office Ph: 979-845-6507

Department of Architecture.............................Lab Ph:979-845-6065

Energy Systems Laboratory.............................FAX: 979-862-2457

Texas A&M University.....................................77843-3581

College Station, Texas, USA, 77843..................URL:www.esl.tamu.edu

8=/  8=)  :=)  8=)  ;=)  8=)  8=()  8=)  :=)  8=)  8=!  8=)  8=? 8=)8=0
________________________________
From: bldg-sim-bounces at lists.onebuilding.org [bldg-sim-bounces at lists.onebuilding.org] on behalf of Jeff Haberl [jhaberl at tamu.edu]
Sent: Saturday, February 05, 2011 4:04 PM
To: Carol Gardner; R B
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Modelling for retrofit ECM's

ALSO:


Here are a few papers that shed light on the ELF/OLF proxy method and other findings, somewhat dated but useful:

 Haberl, J., Komor, P. 1990. “Improving Commercial Building Energy Audits: How Daily and Hourly Consumption Data Can Help,” ASHRAE Journal, Vol. 32, No. 9, pp. 26 - 36 (September).

 Haberl, J., Komor, P. 1990. “Improving Commercial Building Energy Audits: How Annual and Monthly Consumption Data Can Help,” ASHRAE Journal, Vol. 32, No. 8, pp. 26 - 33 (August).



Haberl, J., Komor, P. 1989. “Status Report on Methods for Using Hourly, Daily and Monthly Data to Provide Useful Information on Building Energy Use,” submitted to the New Jersey Energy Conservation Lab, Center for Energy and Environmental Studies at Princeton University, Princeton, New Jersey (May).



Haberl, J., Komor, P. 1989. “Investigating An Analytical Basis for Improving Commercial Building Energy Audits: Early Results from a New Jersey Mall,” Thermal Performance of the Exterior Envelopes of Buildings IV, ASHRAE, Atlanta, Georgia, pp. 302 - 331 (December).


Haberl, J., Komor, P., Haberl, J. 1989. “Investigating An Analytical Basis for Improving Commercial Building Energy Audits: Results from a New Jersey Mall,” Center for Energy and Environmental Studies Report No. 264 (June).

________________________________
From: bldg-sim-bounces at lists.onebuilding.org [bldg-sim-bounces at lists.onebuilding.org] on behalf of Jeff Haberl [jhaberl at tamu.edu]
Sent: Saturday, February 05, 2011 3:44 PM
To: Carol Gardner; R B
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Modelling for retrofit ECM's


Rohini,



Zoning a building is still an art form. There are very few papers that have looked into this with any rigor.



In one thesis we did on the Zachry building, which was the basis for the Predictor Shootout I and II, we looked at 1, 2, 5 and actual zoning on the building. What we saw was that, in general, the centroid of the "cloud" of data points remained about the same. However, the scatter in the cloud became more  pronounced at we added more zones.



So, if all the zones in the floor are being operated the same, I'd use 1, 2 or 5 zones per floor, depending on the functions of what's going on in each zone. Real walls or air walls between the zones usually get the job done.



The quickest way to get the light and receptacle loads on a real building is using "blink" tests, which can be done on a Saturday, with walkie talkies, and a data logger on the whole-building electric feed, possibly some sub feeds. I first heard of this test from Todd Taylor at PNNL. We've used it to help resolved motor loads, lighting loads, receptacles, etc. Seems to work pretty well.



There are also several ways to get the plug loads, including: by proxy, by weather-day-type profiles, by daily readings, and a method that uses an energy balance. The proxy methods can use square proxies for for the occupancy based on OLF/ELF ratios, the weather-day-type method was something that I heard about from Don Hadley at PNNL, later adopted by Bou Saada on the Forrestal building and daycare center. The daily readings are just that, read the main meter by eye, daily, especially during weather independent times. The energy balance method is documented in papers by Claridge et al. at the ESL.



There is also some encouraging work being done by Abushakra and Reddy on ASHRAE RP 1404, now in progress and scheduled for completion later this year. This is based on previous work by Abushakra for his Ph.D. thesis.



Hope this helps.



Jeff



PS: here are some helpful papers:


Song, S., Haberl, J. 2008. “A Procedure for the Performance Evaluation of a New Commercial Building: Part I – Calibrated As-built Simulation”,  ASHRAE Transactions-Research, Vol. 114, Pt. 2, pp. 375-388 (June ).

Song, S., Haberl, J. 2008. “A Procedure for the Performance Evaluation of a New Commercial Building: Part II – Overall Methodology and Comparison of Results”,  ASHRAE Transactions-Research, Vol. 114, Pt. 2, pp. 389 – 403 (June).

Claridge, D., Abushakra, B., Haberl, J. 2003. “Electricity Diversity Profiles for Energy Simulation of Office Buildings (1093-RP),” ASHRAE Transactions-Research, Vol. 110, Pt. 1 (February), pp. 365-377.

Haberl, J., Bou-Saada, T. 1998. “Procedures for Calibrating Hourly Simulation Models to Measured Building Energy and Environmental Data,” ASME Journal of Solar Energy Engineering, Vol. 120, pp. 193 - 204 (August).

Haberl, J., Bronson, D., O'Neal, D. 1995. “An Evaluation of the Impact of Using Measured Weather Data Versus TMY Weather Data in a DOE-2 Simulation of an Existing Building in Central Texas,” ASHRAE Transactions-Research, Vol. 101, Pt.. 2, pp. 558 - 576 (June).

Haberl, J., Bronson, D., Hinchey, S., O'Neal, D. 1993. “Graphical Tools to help Calibrate the DOE-2 Simulation Program to Non-weather Dependent Measured Loads,” ASHRAE Journal, Vol. 35, No. 1, pp. 27 - 32 (January).

Haberl, J., MacDonald, M., Eden, A. 1988. “An Overview of 3-D Graphical Analysis Using DOE-2 Hourly Simulation Data,” ASHRAE Transactions-Research, Vol. 94, Pt. 1, pp. 212 - 227 (January).

Kim, K., Haberl, J. 2010. “Development of a Calibration Methodology for Code-Complaint Simulation With Results From Using a Case-Study House in a Hot and Humid Climate”,  Proceedings of the 17th  Symposium on Improving Building Systems in Hot and Humid Climates, Texas A&M University, Austin, Texas, accepted for publication (May).

Bronson, D., Hinchey, S., Haberl, J., O'Neal, D. 1992. “A Procedure for Calibrating the DOE-2 Simulation Program to Non-Weather Dependent Loads,” ASHRAE Transactions-Research, Vol. 98, Pt. 1, pp. 636 - 652 (January).





8=!  8=)  :=)  8=)  ;=)  8=)  8=(  8=)  8=()  8=)  8=|  8=)  :=')  8=)8=?

Jeff S. Haberl, Ph.D.,P.E., FASHRAE..............jhaberl at tamu.edu

Professor............................................................Office Ph: 979-845-6507

Department of Architecture.............................Lab Ph:979-845-6065

Energy Systems Laboratory.............................FAX: 979-862-2457

Texas A&M University.....................................77843-3581

College Station, Texas, USA, 77843..................URL:www.esl.tamu.edu

8=/  8=)  :=)  8=)  ;=)  8=)  8=()  8=)  :=)  8=)  8=!  8=)  8=? 8=)8=0
________________________________
From: bldg-sim-bounces at lists.onebuilding.org [bldg-sim-bounces at lists.onebuilding.org] on behalf of Carol Gardner [cmg750 at gmail.com]
Sent: Saturday, February 05, 2011 12:59 PM
To: R B
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Modelling for retrofit ECM's

Hi Rohini,

When you are bill matching there are not magical ways of doing things. You pretty much have to put what's in the building in your model. Those things you can control. The tricky part is to figure out how the building is really being operated and to get the most accurate weather data you can for your site.

Cheers,

Carol

On Fri, Feb 4, 2011 at 8:34 AM, R B <slv3sat at gmail.com<mailto:slv3sat at gmail.com>> wrote:

Hi All,
While modelling existing building (with calibration to utility bill), do you model every VAV zone or lump similar ones together? What could be possible disadvantages of lumping down the road? Any ECM's that will be affected by this simplification?
Is there a magical way to figure the W/sqft for lighting and plug loads without having to count everything on site?
Thanks for any insights.
-Rohini

_______________________________________________
Bldg-sim mailing list
http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
To unsubscribe from this mailing list send  a blank message to BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG<mailto:BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG>




--
Carol Gardner PE
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20110206/0e9ea438/attachment-0002.htm>