[Equest-users] ASHRAE Baseline Wall/Window/Roof Constructions This will fix your error

[Thomas Serra]

ASHRAE 90.1 section G is very specific about the wall construction details.
See G3.1(5).  All walls should be Light weight steel framed and roof should
be insulation above deck per your climate zone.  A3.3  details the actual
layers that are used to make up a steel frame wall(see similar sections for
roof and below grade walls).  Remember equest adds the exterior air film
during the simulation, so you won't see the equivalent U value until running
the simulation.  All of my baseline models are done in detailed data mode so
I'm not sure how to accomplish this with the wizard.

 

If you layers are too light, you need to add mass or use the U-value
construction method.

 

Also, we max out the ram on our machines and use dual core processor.  The
dual core doesn't help the modeling speed but allows for multitasking during
simulation and frees up the whole processor for simulation.

 

Thomas Serra

Project Manager

EMO Energy Solutions, LLC

3141 Fairview Park Drive, Suite 450

Falls Church, VA 22042

voice 703-205-0445 ex-113

fax 703-205-0449

 

From: Charles Land [mailto:cland at geo-marine.com] 
Sent: Thursday, February 04, 2010 12:20 AM
To: Supriya Goel; Skelton, Paul; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] ASHRAE Baseline Wall/Window/Roof Constructions
This will fix your error

 

I have never used the specify resistance option in creating a custom
construction. I have always input the actual building materials used (either
in the main menu if they are available, or in the layer by layer
construction if I need to add air gaps and things of that nature).  Im not
sure why you are inputting a specific value but I played with it for a
minute to see what was going on and I got the same error.  If you go under
layer by layer construction in the wizard and pick new construction you need
to put atleast one building material to get rid of the error.  For example I
picked library entry from the first drop down menu  for the first layer and
then chose brick, brick common 4 inch.  This gives an R-value of 0.8.  (you
can see the cumalitive r-value in the bottom left hand corner as you create
your construction.) Then for the second layer I chose specify resistance and
input an r-value of 18.2.  This gives  the specific r-value of 19 your
looking for as well as gets rid of your error.  I think the program is
looking for some type of physical building material and that is why its
giving the error.  You could maybe even try adding another layer of gypsum
board or something (whatever your assuming your actual interior building
material is) and then changing your specified resistance on the middle layer
once again to give you exactly 19.  I believe the program also needs that
outer layer to calculate solar absorbance.  After using this method I went
to detail mode to check the u-value and it showed the construction I made as
having a u-value of 0.053 which is rounded off and coinsides with an r-value
of 19.  And most importantly it gets rid of your error.  Make sure when
specifying your layers you pick vertical exterior wall from the upper right
drop down menu or else it will re-calculate your r-value when running or
coming out of the wizard to match the construction location type.

 

Im not sure what EEMS are but if your talking about the layers in the custom
layer by layer  construction menu its because you haven't chosen a category
for the first construction to allow you to create the next. (either library
entry or specify resistance)

 

I hope this helps.

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Supriya
Goel
Sent: Wednesday, February 03, 2010 5:19 PM
To: Skelton, Paul; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] ASHRAE Baseline Wall/Window/Roof Constructions

 

 

Hi Paul

 

I can't answer all your questions but to answer a few-

 

2. Maybe you can't improve the U value, but can define a completely new
construction through the parametric runs. For that, in the Detail Edit Mode,
Tools-Parametric Runs window, you can create a new run with the component
type -Construction.

3. Yes you can determine the U value of all constructions. Again in the
Detail Edit Mode, open the properties box of the specific construction, it
has a tab which mentions the Calculated U Value.

 

Hope this helps :)

 

Regards

Supriya

On Wed, Feb 3, 2010 at 1:41 PM, Skelton, Paul <pskelton at ids-troy.com> wrote:

Fellow eQuest users,

 

I am brand new to equest and I am attempting to model a baseline ASHRAE
building per the 2004 90.1 standard and am curious if there is any specific
wall, roof or window constructions that other users are entering as their
baseline constructions.  I have noticed several things:

 

1.  Simply entering a resistance (such as an R-value of 11.9) I get a "WALL
has no heat capacity. U-VALUE used" error (see attached)

2.  Defining a layer-by-layer construction does not allow any improvement
through EEMs.  In other words the options to increase the amount of
insulation are grayed out.

3.  It is impossible to determine the actual total U-value of one of the
"cookie-cutter" constructions provided by eQuest.

 

As a side note, I'd be curious to know what computer specs others have to
run eQuest, as I have developed a model with over 3,000 components and it
takes about 6 minutes just to open the file on a computer with the following
specifications:

 

.         Intel Pentium D 2.99 GHz

.         1 GB RAM

.         ATI Radeon X600 - Video card

.         29 GB HDD

 

The specs on this computer are terrible in my eyes, and it really shows when
I try to run eQuest but I'd like to see what other PCs run this program
effectively.

 

Thanks,

 

Paul Skelton

Integrated Design Solutions
Architecture, Engineering, Interiors & Technology
888 West Big Beaver, Suite 200
Troy, Michigan 48084
tel:   248.823.2171
fax: 248.823.2200
 <http://www.ids-troy.com/> www.ids-troy.com

Celebrating 10 Years.  Expect the Exceptional. 

 

 

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-- 
Graduate Student, MSBE
School of Architecture and Landscape Architecture
Arizona State University, Tempe






-- 
Graduate Student, MSBE
School of Architecture and Landscape Architecture
Arizona State University, Tempe



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