[Equest-users] newbie question on simple modeling

Carol Gardner cmg750 at gmail.com
Wed Oct 27 14:04:53 PDT 2010


I agree with every thing Nick said. I'd add that if you want to calibrate
your model to actual utility bills a very important thing to understand is
how the building is used, i.e., when are people arriving? Leaving? How and
when are lights, equipment, etc. turned on? How is the HVAC system operated?
All of this information goes into schedules which modify the number of
people (total bldg population), w/sf of light and HVAC systems. These
schedules are the "art" of calibration and the most powerful tool to use.
The other thing that will impact your calibration will be the weather file,
which you unfortunately can't control unless you want to create your own
file. Overkill.

This being said, if you are just examining a condition like a window change
out you don't really need to calibrate, I don't think. As Nick said in his
first response you're just looking at a before and after condition -
existing window vs new window so I don't think having a precise model of
your building will matter so much.

Maybe others will disagree. If so bring it on!

On Wed, Oct 27, 2010 at 10:19 AM, Nick Caton <ncaton at smithboucher.com>wrote:

>  Sounds like you’ve run head-on into a conundrum we all continually face
> as energy modelers – how accurate is accurate enough?
>
>
>
> The savings generated by any glazing retrofit ultimately boil down to
> altering the envelope loads the building has to deal with
> (solar/conductive)*.  Your real goal is to have those loads’ magnitudes in
> the right ballpark before doing a comparison.
>
>
>
> You should definitely try to use the real-world utility rates, location,
> geometries and envelope constructions of the existing building for this
> study when making your baseline in the wizards.
>
>
>
> To what degree you should calibrate your baseline results depends on your
> time available, ability (what you can do in that time) and what degree of
> accuracy is desired in the results – it’s ultimately your call.  If you’re a
> total beginner without time to burn, I’d suggest at a bare minimum to
> collect and try to roughly match some historical utility bills on an annual
> basis.  If the actual building spends $200,000 a year on gas/electricity and
> your generic baseline spits out half that, you will definitely want to
> improve your model before generating/sharing any results.   This would
> provide a (rough) measure of whether your model is accurately ball parking
> the envelope loads correctly.
>
>
>
> You’re correct regarding the overall procedure: make the baseline first,
> check and calibrate its behavior to the degree you feel appropriate, then
> change the glazing for comparative results.
>
>
>
> You might do well to read up on parametric runs first to save yourself time
> and streamline the process – then you can simultaneously explore multiple
> alternatives within one file.  Also don’t miss the significance of the “use
> floor multipliers” checkbox in the wizards whenever doing high-rise building
> models.
>
>
>
> ~Nick
>
>
>
> *… unless there’s daylighting controls involved too, in which case you
> should collect as much info regarding those lightings systems/controls as
> you can to match in your baseline as well!
>
>
>
> [image: cid:489575314 at 22072009-0ABB]**
>
> * *
>
> *NICK CATON, E.I.T.***
>
> PROJECT ENGINEER
>
> 25501 west valley parkway
>
> olathe ks 66061
>
> direct 913 344.0036
>
> fax 913 345.0617
>
> *Check out our new web-site @ *www.smithboucher.com* *
>
>
>
> *From:* Darrell Cherry [mailto:DCherry at jeberkowitz.com]
> *Sent:* Wednesday, October 27, 2010 10:43 AM
> *To:* Nick Caton
> *Subject:* RE: [Equest-users] newbie question on simple modeling
>
>
>
> Nick, thank you.  What specific parameters would you recommend I obtain
> from building owner in order to provide more realistic analysis?  Rates?
> HVAC plant and zoning info? Time-of-use rates?  Etc.?
>
>
>
> I assume what I need to do is create a baseline of the current building and
> its current energy costs/rates and after that is done I will simply change
> the one component I plan to affect; i.e. glazing, and then run the
> comparison.
>
>
>
>
>
> Cordially,
> *Darrell Cherry* |* **Projects Manager*
> *JE Berkowitz, LP | **Architectural Glass Since 1920*
> One Gateway Boulevard | Pedricktown, NJ  08067
> *T* 800.257.7827 x207|* **F* 856.299.4344 |* **C* 856.229.1598
> dcherry at jeberkowitz.com | www.jeberkowitz.com
>
> ** * * * * *** *** * * * *** **CONFIDENTIALITY NOTICE * * * * * * *** ***
> * * * **
> This email including any files transmitted with it, are confidential and
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> entirety, from your system.
>
>   ------------------------------
>
> *From:* Nick Caton [mailto:ncaton at smithboucher.com]
> *Sent:* Wednesday, October 27, 2010 11:37 AM
> *To:* Darrell Cherry; equest-users at lists.onebuilding.org
> *Subject:* RE: [Equest-users] newbie question on simple modeling
>
>
>
> “Is this just too simplistic for eQuest?”
>
>
>
> …There’s  a question we don’t see often here =)!
>
>
>
> eQuest can be used to quickly build a generic 19-story office building from
> the wizards.
>
>
>
> eQuest can easily be used to compare the effects of two glazing materials.
>
>
>
> What eQuest cannot do (nor any other software), is calibrate to *
> accurately* model “current annual energy costs” and “improved” costs with
> only one bit of information – glass type.
>
>
>
> As long as you intend to estimate “relative annual energy savings,” you
> should be fine using eQuest to make as simplified a comparison as you might
> desire.
>
>
>
> Just keep in mind: the less effort spent attempting to match reality with
> your baseline model, the more of an estimate the whole exercise really is.
>
>
>
> ~Nick
>
> [image: cid:489575314 at 22072009-0ABB]**
>
> * *
>
> *NICK CATON, E.I.T.***
>
> PROJECT ENGINEER
>
> 25501 west valley parkway
>
> olathe ks 66061
>
> direct 913 344.0036
>
> fax 913 345.0617
>
> *Check out our new web-site @ *www.smithboucher.com* *
>
>
>
> *From:* equest-users-bounces at lists.onebuilding.org [mailto:
> equest-users-bounces at lists.onebuilding.org] *On Behalf Of *Darrell Cherry
> *Sent:* Wednesday, October 27, 2010 9:54 AM
> *To:* equest-users at lists.onebuilding.org
> *Subject:* [Equest-users] newbie question on simple modeling
>
>
>
> I need to utilize eQuest for basically one simple purpose; i.e. I am
> looking to change ONLY the makeup of the windows in a 19-story office
> building from monolithic glazing to a triple-glazed system.  The frame WILL
> NOT change.
>
>
>
> What I need to model is the current annual energy costs vs ne costs with
> improved fenestration system.
>
>
>
> Is this just too simplistic for eQuest?
>
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>


-- 
Carol Gardner PE
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