[Equest-users] Fwd: Composition of weather file data

Joe Huang yjhuang at whiteboxtechnologies.com
Tue Feb 11 18:45:52 PST 2014


David,  no, can't you tell :-)

Could you explain to me in simple layman's terms what is "pre 
retro-commissioning" ?  I know what's commissioning, and even have a 
good idea what's "retro-commissioning", but "pre retro-commissioning" ?  
Is that like preparing to get ready to do something ?

Joe


On 2/11/2014 6:27 PM, David Eldridge wrote:
>
> Joe, you aren't performing "p-RCx energy models" very often?
>
> But seriously Arunabha, the magnitude of RCx savings for a facility 
> may not be a high percentage of the total usage -- although the 
> measures are low-cost and quick payback -- energy modeling used as 
> part of RCx should try to use actual weather data if possible or else 
> the variances due to weather might be the same magnitude as the RCMs 
> if you are attempting any significant level of calibration for the model.
>
> However you should then run the proposed case with typical weather in 
> order to model an "expected" annual savings.
>
> Depending what measures you are modeling and whether you have any 
> calibration data during the "p-RCx" phase, typical weather could work 
> well enough, at least to get started and see if you should continue 
> using the model for this purpose.
>
> David
>
> __
>
> David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP
>
> *Grumman/Butkus Associates*
>
> __
>
> *From:*Joe Huang [mailto:yjhuang at whiteboxtechnologies.com]
> *Sent:* Tuesday, February 11, 2014 2:43 PM
> *To:* Arunabha Sau; David Eldridge; equest-users at lists.onebuilding.org
> *Subject:* Re: Fwd: Composition of weather file data
>
> It's inevitable that the peak conditions will fluctuate from year to 
> year, that's just the chaotic nature of the weather.  If you
> use a "typical year" weather file, you will tend to get, but not 
> necessarily, an average annual peak, since the months have been 
> selected to best match the long-term distribution of temperatures, 
> humidity, solar, wind speed, etc.
>
> What is pre-RCx ?  "pre retro-commissioning"?  What is that?  Too many 
> adjectives for me :-)
>
> In any case, if you're modeling an existing building to assess its 
> historical performance, I would definitely use actual year weather files.
> As for where to find such data, there's a proliferation of sources on 
> the Web, although most would require processing to turn them into 
> formats required by simulation programs such as eQUEST, etc.
>
> Joe
> Joe Huang
> White Box Technologies, Inc.
> 346 Rheem Blvd., Suite 108D
> Moraga CA 94556
> yjhuang at whiteboxtechnologies.com <mailto:yjhuang at whiteboxtechnologies.com>
> http://weather.whiteboxtechnologies.com for simulation-ready weather data
> http://www.whiteboxtechnologies.com
> (o) (925)388-0265
> (c) (510)928-2683
> "building energy simulations at your fingertips"
>
>
> On 2/11/2014 4:09 AM, Arunabha Sau wrote:
>
>     Thanks Joe & David.
>
>     Appreciate your explanation. It was very through.
>
>     In an EPW file, I saw only 1990's data, so I was worried about the
>     peak if the typical years's data would be different or so! I was
>     modeling for pre-RCx. So, I was more concerned about actual (or
>     near to actual) heating/cooling load.
>
>     For Cx modeling, do you guys make model out of these weather file
>     or make a more customized weather file from some online available
>     weather file source or buy one?
>
>     Best regards,
>
>     Aru
>
>     /~~~/
>
>     /Texas Aggie '10/
>
>     /JU, Kolkata '05/
>
>     /~~~/
>
>     /Try not to become a man of success, but rather try to become a
>     man of value./**
>
>     - Albert Einstein
>

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