[Equest-users] Scale modeling

[CleanTech Analytics]

Thanks I will keep that in mind..
I kinda enjoy the eQuest interface, so it is good to know there are
modeling tasks that it shines in! It has a nice parametric skylight tool
and good libraries, so will now be my tool of choice when skylights are
involved..

*Jeremiah D. Crossett*
*CleanTech Analytics*
*503-688-8951*
*www.cleantechanalytics.com* <http://www.cleantechanalytics.com>


*

This document may contain valuable information proprietary to CleanTech
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stored or transmitted in any form without the prior written consent of
CleanTech Analytics
*



On Mon, Apr 9, 2012 at 11:05 PM, Stefano Moret <smoret at ucdavis.edu> wrote:

>  Thanks all for your considerations, I much appreciate your
> recommendations.
> The nice thing about E-quest is that it support some elements, e.g.
> skylights, with many different features, while in Energyplus they are
> usually treated as normal windows.
>
>  Thanks again, Cheers
> Stefano
>
>  --
>
>  Stefano Moret
> California Lighting Technology Center <http://cltc.ucdavis.edu/>
> University of California, Davis
> 633 Pena Drive
> Davis, CA 95618
>
> 530-747-3846
> smoret at ucdavis.edu
>
>  On 09/apr/2012, at 18.28, CleanTech Analytics wrote:
>
> I had all to similar issues with eQuest, and and realized that eQuest is
> not really a reliable software. *I know the list is going to hate me.. The
> thing is that eQuest is deceptively easy, but when you want to find
> reliable results you basically have to find some "workaround"...
>
>  The deal breaker for me in using eQuest for anything more then exploring
> early design options was:
>
>  I had several real buildings complete with Energy Star portfolio manager
> data, as well as building audits, when I attempted to use eQuest discovered
> that eQuest was not capable of coming close to reality, in fact it wanted
> me to have something like zero insulation, and very poor U values to even
> come close. Given Energy Plus is not going to give exact results either but
> at least it comes close.
>
>  Watch the lists, eQuest is full of "how do I come up with a work
> around", TRNSYS is mostly "how do I customize" and Energy Plus is mostly
> "how does this feature work"
>
>  I do not mean to insult eQuest users but my prospective is that it makes
> more since to use software that is harder to use, has better support and is
> updated regularly for such professional and high paid work, rather then the
> "workaround"
> Why eQuest is so popular is because it is easy, but for something like
> your project I suggest you use Energy Plus.
>
>
>  *Jeremiah D. Crossett*
> *CleanTech Analytics*
> *503-688-8951*
>  *www.cleantechanalytics.com* <http://www.cleantechanalytics.com/>
>
>
>   *
> This document may contain valuable information proprietary to CleanTech
> Analytics which is private and confidential. It may not be shared, copied,
> stored or transmitted in any form without the prior written consent of
> CleanTech Analytics
> *
>
>
>
> On Mon, Apr 9, 2012 at 4:30 PM, Stefano Moret <smoret at ucdavis.edu> wrote:
>
>>  Dear Nick,****
>>
>> ** **
>>
>> Thanks for your suggestions, I totally agree with your points, and I’m
>> conscious of the issues about the “generic guidelines”. I’m still surprised
>> by some unexpected results in my models though: I’ll work on my models to
>> try to understand the reasons leading to results which are different from
>> the measured ones.****
>>
>> ** **
>>
>> Thanks, Stefano****
>>
>> ** **
>>
>> *From:* Nick Caton [mailto:ncaton at smithboucher.com]
>> *Sent:* Monday, April 09, 2012 3:57 PM
>> *To:* Karen Walkerman; Stefano Moret
>> *Cc:* equest-users at lists.onebuilding.org
>> *Subject:* RE: [Equest-users] Scale modeling****
>>
>> ** **
>>
>> …I see my response is arriving too late to the conversation but here are
>> some further thoughts that might help Stefano and others:****
>>
>> ** **
>>
>> I have some parallel experience from which I can build/add to Karen’s
>> suggestions.****
>>
>> ** **
>>
>> I have performed studies with similar structure as Karen is suggesting
>> (creating and adding “building blocks” to evaluate building massing
>> options).  However, for Stefano’s purposes I would caution to carefully
>> take stock of what questions you are trying to answer and whether an energy
>> model is really the way to go about finding those answers. ****
>>
>> ** **
>>
>> Using an energy model to develop generic guidelines with “arbitrary”
>> buildings/spaces for something inherently
>> site/climate/building-geometry-specific  (such as “ideal window wall ratio”
>> or “ideal window properties”) is actually a terribly complex endeavor, as
>> I’m sure you are appreciating.  You can ultimately come up with a set of
>> guidelines/spreadsheets/principles to use, but applying such developed
>> guidelines to an actual project for decision-making will always be fraught
>> with accuracy disclaimers  (perhaps that is not the ultimate goal – I’m
>> only throwing this out for consideration).  ****
>>
>> ** **
>>
>> Guidelines built around generic conditions are indeed useful and have
>> their place (ASHRAE’s advanced energy design guides are worth reviewing if
>> you’re at the outset of trying to find such results), but should only be
>> relied upon in the context of “I don’t want to invest in a site-specific
>> study and the increased accuracy / differing suggestions that may
>> produce.”  Evaluating how well any study applies to the project-at-hand is
>> something to always keep in mind.****
>>
>> ** **
>>
>> To cut myself off:  I think my response drafted so far is falling away
>> from Stefano’s original question as he’s more recently clarifying it, but
>> I’m ultimately driving towards furthering Karen’s first line:  Build
>> project-specific models where you need a project-specific answer.****
>>
>> ** **
>>
>> To Stefano’s issue of scaling – I am nodding my head vigorously as you’re
>> observing how spaces modeled in isolation do not always additively
>> represent a group of spaces modeled together.  It’s possible for that to
>> happen under certain circumstances, but the variables in play do not
>> normally scale linearly between an isolated space and a whole building
>> (consider the ratio of envelope surface area to conditioned volume, for one
>> instance).  A big part of “big picture” modeling differences when compared
>> to “the smaller parts” is the tempering of various loads across spaces and
>> the way that has energy saving effects on HVAC systems in particular .  *
>> ***
>>
>> ** **
>>
>> I would not spend too much time deliberating on such (expected)
>> differences, and would emphasize focusing on the results of isolated or
>> “whole building” models as appropriate to the purpose of your study =).**
>> **
>>
>> ** **
>>
>> ~Nick****
>>
>> ** **
>>
>> [image: cid:489575314 at 22072009-0ABB]**
>>
>> * *
>>
>> *NICK CATON, P.E.*
>>
>> SENIOR ENGINEER****
>>
>> ** **
>>
>> Smith & Boucher Engineers****
>>
>> 25501 west valley parkway, suite 200****
>>
>> olathe, ks 66061****
>>
>> direct 913.344.0036****
>>
>> fax 913.345.0617****
>>
>> www.smithboucher.com* *****
>>
>> ** **
>>
>> *From:* equest-users-bounces at lists.onebuilding.org
>> [mailto:equest-users-bounces at lists.onebuilding.org] *On Behalf Of *Karen
>> Walkerman
>> *Sent:* Monday, April 09, 2012 4:18 PM
>> *To:* Stefano Moret
>> *Cc:* equest-users at lists.onebuilding.org
>> *Subject:* Re: [Equest-users] Scale modeling****
>>
>> ** **
>>
>> The short answer is that every building is different, and there is no
>> "typical" model that will fit them all.****
>>
>> ** **
>>
>> As you mentioned, the ratio between lighting/cooling/heating changes
>> depending on the size of the building.  I'm willing to guess that this is
>> because the core zones that have very little need for heat get much larger
>> in relation to the perimeter zones.  Also, the building energy needs will
>> change depending on orientation and global location.****
>>
>> ** **
>>
>> I would suggest that you take a slightly different approach - try to come
>> up with values that are representative for different types of spaces.  You
>> might do say:****
>>
>> ** **
>>
>> 1.  A perimeter office space with XX% glazing (run for North, East, South
>> and West exposures)****
>>
>> 2.  A core office space with no skylights****
>>
>> 3.  A core office space with XX% of roof area as skylights****
>>
>> 4.  A core manufacturing space???****
>>
>> 5,6,7....****
>>
>> ** **
>>
>> Run each model in the applicable climate.  Then, if you have an office
>> building that is 70% core and 30% perimeter space, you'll have a better
>> understanding of the building.  This is still a very rough approximation,
>> but should get you farther than trying to model one "typical" building.**
>> **
>>
>> ** **
>>
>> --****
>>
>> Karen****
>>
>> ** **
>>
>> ** **
>>
>> On Mon, Apr 9, 2012 at 4:57 PM, Stefano Moret <smoret at ucdavis.edu> wrote:
>> ****
>>
>> Dear all,****
>>
>>  ****
>>
>> I've recently played around quite a bit with E-quest to simulate the
>> effect of dynamic fenestration on building energy consumption. ****
>>
>> For these simulations I've been using a very simple office model with a
>> skylight on the top as a test-bed for my calculations (with default system
>> for HVAC and daylighting controls with dimming for lights) but, observing
>> the values I'm obtaining in output, I see that the values I obtain for
>> lighting, cooling and heating consumption make sense relatively, i.e. if
>> compared to themselves in different conditions, but are sometimes of
>> totally different order of magnitude if compared to each other
>> (lighting/cooling loads are often much higher than heating, by orders of
>> magnitude), especially when scaling up the model to bigger sizes. This way,
>> it's very difficult to see the effect of a variable change on the total
>> energy consumption. ****
>>
>>  ****
>>
>> I know the model I'm using is very idealized, but is there any variable
>> that I can act on in order to obtain a model which has energy consumption
>> values more similar to a real building? For example, is there a "suggested"
>> size of the building that gives better results? Or maybe simulating a
>> single room in a large building gives more realistic results than the
>> single room alone? ****
>>
>> My point is that I would like to have a model whose results in scale
>> might be consistent when applied to bigger buildings. ****
>>
>>  ****
>>
>> Thanks for your hints and suggestions, ****
>>
>> Stefano****
>>
>>  ****
>>
>> --****
>>
>>  ****
>>
>> Stefano Moret
>> California Lighting Technology Center <http://cltc.ucdavis.edu/>
>> University of California, Davis
>> 633 Pena Drive
>> Davis, CA 95618****
>>
>> 530-747-3846
>> smoret at ucdavis.edu <smoret at ad3.ucdavis.edu> * ***
>>
>>  ****
>>
>>
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>>
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>>
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