[bldg-sim] wind speed data in TMY2 files

[Jeff Haberl]

Sorry, I should have made this more clear. 

The "ground temps" that show up when one runs DOE-2 are from Kusuda's algorithm. These are calculated by internally by DOE-2 in the absense of data on the file. These values are also used by default for the water source temperatures for DHW. One can replace either or both of these with real monthly average temps in the input file. 

Jeff 
BB 8=!  8=)  :=)  8=)  ;=)  8=)  8=(  8=)  :=')  8=)  8=)  8=? BB

Jeff S. Haberl, Ph.D., P.E.............................jhaberl at esl.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.......................URL: www-esl.tamu.edu

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-----Original Message-----
From: Drury.Crawley at EE.DOE.GOV <Drury.Crawley at EE.DOE.GOV>
To: Jeff Haberl <jeffhaberl at tees.tamus.edu>
Sent: Sun Sep 18 22:43:38 2005
Subject: Re: [bldg-sim] wind speed data in TMY2 files


Jeff,

TMY2s don't have ground temps.

Dru



                                                                                                        
                      "Jeff Haberl"                                                                     
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                      Sent by:                 Subject:  [bldg-sim] wind speed data in TMY2 files       
                      bldg-sim at gard.com                                                                 
                                                                                                        
                                                                                                        
                      09/18/2005 10:49 PM                                                               
                      Please respond to                                                                 
                      jeffhaberl                                                                        
                                                                                                        
                                                                                                        
                                                                                                        



FYI

This point was well described by Geoff Levermore in his recent ASHRAE
Seminar presentation, where he showed side-by-side measurements of  contact
anemometers vs more accurate ultrasound sensors. This will cause
under-predictions of buildings being analyzed for natural ventilation.

So, until TMY2 files are recompiled with new data, or corrected somehow, we
are all at least using the same bad data. Oh and don't forget the
suspicious ground temperatures,  and as yet to be compiled service water
temperatures, both potential fodder for future ASHRAE RPs.

Jeff
BB 8=!  8=)  :=)  8=)  ;=)  8=)  8=(  8=)  :=')  8=)  8=)  8=? BB

Jeff S. Haberl, Ph.D., P.E.............................jhaberl at esl.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.......................URL: www-esl.tamu.edu

BB 8=/  8=)  :=)  8=)  ;=)  8=)  8=()  8=) 8=?  8=)  8=)  8= BB


-----Original Message-----
From: Andy Lau <asl1 at psu.edu>
To: Jeff Haberl <jeffhaberl at tees.tamus.edu>
Sent: Sun Sep 18 18:37:54 2005
Subject: Re: [bldg-sim] wind speed data in TMY2 files

Jeff,

Thanks.  Do you know of any investigations that have tried to better
quantify the error?   Cutting out below 3-5 mph is not a big problem if
using the data to predict turbine performance because they typically do not

operate below 5-8 mph.

Andy
At 03:20 PM 9/18/2005, you wrote:
>I believe these are derived from NWS measurements, which tend to be 10
>meter towers. However, the problem with NWS wind data is that it
>represents an average of a 3-5 minute snapshot taken 15 minutes before the

>hour, and thus seriously overstates the integrated average wind speed
>taken over the whole hour.
>
>Also, until quite recently,  these were taken with contact anemometers
>that cut-out below 3-5 MPH, which understates the amount of wind at low
>wind speeds.
>
>Jeff
>BB 8=!  8=)  :=)  8=)  ;=)  8=)  8=(  8=)  :=')  8=)  8=)  8=? BB
>
>Jeff S. Haberl, Ph.D.,
P.E.............................jhaberl at esl.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.......................URL: www-esl.tamu.edu
>
>BB 8=/  8=)  :=)  8=)  ;=)  8=)  8=()  8=) 8=?  8=)  8=)  8= BB
>
>
>-----Original Message-----
>From: bldg-sim at gard.com <bldg-sim at gard.com>
>To: bldg-sim at gard.com <bldg-sim at gard.com>
>Sent: Sat Sep 17 07:45:10 2005
>Subject: [bldg-sim] wind speed data in TMY2 files
>
>Does anybody know at what height the TMY2 wind speed data was measured?
>
>
>
>Andy Lau, Associate Director, Center for Sustainability, Penn State
>213-F Hammond Building, University Park, PA 16802
>814-863-9075, 814-863-7229 (FAX), andylau at psu.edu, www.engr.psu.edu/cfs
>
>
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