[Bldg-sim] differences between energy simulations programs

Wed Mar 24 14:58:37 PDT 2010

The heat balance switches direction at night. From the blocks  
absorbing heat in the day to giving it off at night. A trombe wall  
also works this way.

In reference to your last question, where a building is designed to  
maximise passive solar then yes exposed concrete could work better.

For a traditionally serviced building, if it's heating intensive but  
also intermittently heated, go lightweight and well insulated. If it's  
cooling intensive maximise exposed thermal mass.

Sent from my iPhone

On 24 Mar 2010, at 20:05, "Paul Grahovac" <paul.grahovac at prosoco.com>  
wrote:

> I don't know what methodology my people used.  I appreciate everyone's
> input. I am concerned I should remain a viewer and not a participant  
> on
> this listserv since I am not a modeler -- only a consumer of modeling
> services.  One data point that is not data, but confirmed to me that
> thermal mass is real:  I brought an energy auditor to an
> minimally-heated greenhouse at night and asked him to point his
> thermographic gun at everything --including the concrete blocks  
> holding
> up the planting platforms.  Everything was blue and cold except the
> concrete blocks which were yellow-red warm.
>
> Paul Grahovac, LEED AP
> PROSOCO, Inc.
> 785-393-1816 cell
>
> -----Original Message-----
> From: Clark Denson [mailto:cdenson at ssr-inc.com]
> Sent: Wednesday, March 24, 2010 2:40 PM
> To: Paul Grahovac; Eurek, John S NWO; Peterson, John (EYP/HP CFS);
> bldg-sim at lists.onebuilding.org
> Subject: RE: [Bldg-sim] differences between energy simulations  
> programs
>
> The way I understand it, the effect of thermal mass is all in how the
> heating/cooling loads are calculated.  TRACE is unique from many other
> programs in that the user can choose the heating/cooling load
> methodology that will be used.  Depending on your choice, thermal mass
> will be calculated differently.  Most incorporate some kind of  
> Transfer
> Function Method (TFM), and each method is based on calculations and
> algorithms from ASHRAE publications such as the 1972, 1985, and 2001
> ASHRAE Fundamentals Handbooks, ASHRAE Research Project #359, and the
> ASHRAE Toolkit for Building Load Calculations.
>
> So the question of "What are the differences between TRACE and Energy
> Simulation program 'X'?" is complicated by the additional question,
> "Which Load Calculation Methodology in TRACE did you select?"
>
> Clark Denson, PE
>
>
> -----Original Message-----
> From: Paul Grahovac [mailto:paul.grahovac at prosoco.com]
> Sent: Wednesday, March 24, 2010 10:36 AM
> To: Eurek, John S NWO; Peterson, John (EYP/HP CFS);
> bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] differences between energy simulations  
> programs
>
> FYI, another comment on TRANE Trace 700:  the modeling engineers I  
> hired
> told me, after consultation with TRANE, that exposed interior concrete
> floors, when modeled against the ASHRAE baseline of carpeted floors,
> showed a reduction in the cooling load, but an increase in the heating
> load.  An increase in the heating load was contrary to my reading in
> passive solar books.  I used a simplified simulator for lay people,  
> and
> it showed exposed interior concrete floors improved cold-weather
> performance over carpeted concrete (HEED, www2.aud.ucla.edu/heed).
>
> I have since heard that TRANE does not model thermal mass well.  I  
> have
> also not been able to find anyone with experience modeling the thermal
> mass of interior exposed concrete floors using any simulation tool.
>
> Paul Grahovac, LEED AP
> PROSOCO, Inc.
> 785-830-7355
>
> -----Original Message-----
> From: bldg-sim-bounces at lists.onebuilding.org
> [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Eurek,  
> John
> S NWO
> Sent: Wednesday, March 17, 2010 3:32 PM
> To: Peterson, John (EYP/HP CFS); bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] Discrepancy between Equest & Trace 6.2
>
> John,
>
> It is like buying a car.  Do you want a truck, manual/automatic,
> something
> fast.......  You are asking for information overload.  If you know
> exactly
> what you want it may be easier for us (in this list) to help guide you
> to the
> best option.
>
> I also was once curious and found the link below.  The end of the  
> paper
> has
> charts comparing different features.
> http://apps1.eere.energy.gov/buildings/tools_directory/pdfs/contrasting_
> the_c
> apabilities_of_building_energy_performance_simulation_programs_v1.0. 
> pdf
>
> Another sight.
> http://www.wbdg.org/resources/energyanalysis.php
>
>
> I use Trace 700 (v6.2.4).  Why? Because the first, second and third
> company I
> worked for used it.  It is good for running loads, but so-so for  
> energy
> modeling.  Also I have never used anything else.  I have looked at
> equest and
> DOE, they both look like learning a completely new programming  
> language.
>
>
> I wouldn't mind hearing other people's brief views of the programs  
> they
> use.
> Equest, DOE, HAP, ect.
>
>
>
> John Eurek LEED AP
> Mechanical Engineer,
> US Army Corps of Engineers
> Omaha District CENWO-ED-DA
> 1616 Capitol Avenue
> Omaha, NE 68102
> Phone: (402) 995-2134
> email: john.s.eurek at usace.army.mil
>
>
> -----Original Message-----
> From: bldg-sim-bounces at lists.onebuilding.org
> [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Peterson,
> John
> (EYP/HP CFS)
> Sent: Wednesday, March 17, 2010 2:03 PM
> To: bldg-sim at lists.onebuilding.org
> Subject: [Bldg-sim] Discrepancy between Equest & Trace 6.2
>
>
>
> Has there been any information released on the differences between
> energy
> simulation programs?  We have a bid requirement with a certain
> percentage
> listed and we have been asked to address the differences between the  
> bid
> model and the newly proposed model.
>
>
>
> Thanks in advance -
>
> John
>
>
>
> John Peterson, PE, LEED AP
>
> HP Critical Facilities Services delivered by EYP
>
> 6600 Rockledge Drive, 4th Floor
>
> Bethesda, MD  20817
>
> cell: 202-731-5835
>
>
>
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