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

[Arunabha Sau]

Yea, David. Joe is just making the state-of-art weather files thru' ASHRAE
research projects but he is not performing any "p-RCx"!! :)

Thanks David. Appreciate the reply.The EPW Indian weather files typically
from 1990s. It's typical year weather file. But I don't think I should use
this old weather file in Cx model. My project is a fairly simple model with
few simple EEMs - efficient chiller and air side economizer.
Of course I can calibrate the model to the current energy usage. Do you
think using the 1990 weather file would be good way?

Cheers!
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



On Wed, Feb 12, 2014 at 7:57 AM, David Eldridge <DEldridge at grummanbutkus.com
> 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
> 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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