[Equest-users] U-Values

Wed Jun 9 09:37:45 PDT 2010

Peter et al,

Nick said what I was going to say!  I'm guessing at this point that your
climate is fairly warm (i.e. Georgia climate) and that the increased insul
is like Nick stated (over-insulating) for the cooling aspect of your model.

I had a project once on a college campus in Canada where the design team did
such a good job at thier ECM design stratagies that they over-designed the
building and moved the building characteristics from being a heating
dominated cimate building to being cooing dominated.  We (as the sim team)
made the recommendations that they actually remove thier ventilation heat
recovery systems (completely) and lessen the "thightness" of the envelope
design so that the building could experience some losses through the skin
and balance out the energy use of the building operations.  This was the
first time I've had to recommend to "scale back" on the design strategies.
(FYI-the HVAC was tied to a geothermal loop that needed to have more
balanced energy use for it's proper operation.  With too much cooling to the
ground the geothermal system was becoming unbalanced.  For the real
simulation-techies, we then integrated our simulations with TRNSYS to
replicate the increasing ground temps that would be resultant if the
building energy was not better balanced in the design to work with the
geothermal system & well field.)

Just like for so many of us when this light bulb goes on we can really see
the value of energy simulation for aiding design choices and this is when
energy modeling is actually FUN!  :)

pasha
On Wed, Jun 9, 2010 at 10:19 AM, Peter Hillermann <
e190984026 at exchange.1and1.com> wrote:

>  To my friends on the list,
>
>
>
> Those explanations have made perfect sense. Nick this too is the reason I
> am absolutely enjoying it. I was just telling my boss how your perception of
> design changes when you introduce what could actually be going on. I love
> the analogy Nick posted about trapping heat in the summer. It makes perfect
> sense because the more you insulate a building the better it is at NOT
> transmitting heat energy. So you put 1 piece of storefront on your building
> that introduces radiant heat to your floor and you’re cooking the inside or
> like you said one piece of equipment generating enough heat and it won’t let
> it escape.
>
>
>
> Thanks Nick light bulb just went off.
>
>
>
> Thanks,
>
>
>
> *PETER HILLERMANN*
>
>
>
> peterh at westallarchitects.com
>
>
>
> *westall*
>
> *architects*
>
> 3404 pierce drive
>
> chamblee, georgia 30341
>
>
>
> o 770.458.4113
>
> f  770.458.5352
>
> c 678.898.2936
>
>
>
> westallarchitects.com
>
> [image: e-signature][image: USGBC-Logo]
>
>
>
>
>
>
>
> *From:* Nick Caton [mailto:ncaton at smithboucher.com]
> *Sent:* Wednesday, June 09, 2010 12:03 PM
> *To:* Peter Hillermann; equest-users at lists.onebuilding.org
> *Subject:* RE: [Equest-users] U-Values
>
>
>
> Peter,
>
>
>
> This is the exact reason I’ve come to really enjoy energy modeling.
> Anytime you get results that you don’t expect, whether your preconceptions
> are right or wrong, you’re bound to learn something – sometime profound!
>
>
>
> You must make the call on whether this makes sense ultimately, but there
> are probably reasonable explanations for what you’re seeing.  It would help
> us help you if you shared more, like what climate the building is in, what
> systems you’re using… etc.  You will want to come up with explanations, then
> investigate the model results to see if that syncs with the behavior
> modeled.
>
>
>
> As a start: R-27 is a high wall value – Note that walls/roofs can be both
> over- and under-insulated.  Likely, you’re seeing gas savings from losing
> less heat in the winter and thus having less heating load, while
> simultaneously trapping heat inside your building during the cooling months,
> increasing your cooling equipment loads.  Hard to make more specific guesses
> without more information.
>
>
>
> Sidenote – take care that you’re not skewing results by wiping out the
> effects of wall studs when comparing a new baseline insulation value (Re:
> Table A9.2.B, 90.1-2004/2007).
>
>
>
> ~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 *Peter
> Hillermann
> *Sent:* Wednesday, June 09, 2010 10:48 AM
> *To:* equest-users at lists.onebuilding.org
> *Subject:* [Equest-users] U-Values
>
>
>
> To All,
>
>
>
> I seem to be having some issues with my baseline design and my first
> parametric run. (I am working in detail mode with INP file) When I make my
> baseline wall value R-13 and change it in my run to R-27 my heating (MBTU)
> load goes down by 4% however my electric rate (kWh) goes up 1%. I don’t
> really understand because I thought both would have gone down. Am I doing
> something wrong?
>
>
>
> Thanks,
>
>
>
> *PETER HILLERMANN*
>
>
>
> peterh at westallarchitects.com
>
>
>
> *westall*
>
> *architects*
>
> 3404 pierce drive
>
> chamblee, georgia 30341
>
>
>
> o 770.458.4113
>
> f  770.458.5352
>
> c 678.898.2936
>
>
>
> westallarchitects.com
>
> [image: e-signature][image: USGBC-Logo]
>
>
>
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