[Bldg-sim] Trace 700 vs eQuest

Kristin Field KField at archenergy.com
Thu Jan 10 13:35:55 PST 2008


To improve on eQUEST loads calculations, you can always choose a design day in Detailed Data Edit mode.  Make sure your CDD and HDD schedule values are what you would want them to be on a heating/cooling design day, and specify a design day in the "Project & Site" area.  You do this by right-clicking on "Project: <uname>," which appears on the top of the list at the left of your screen, directly above a folder called "Global Parameters."  Then you choose "Create Design Day" and go from there.  When you run the simulation, equipment should be sized based on the loads calculated on this design day.  In your .sim file, most/all of the loads reports have "standard" and "design day" pages so that you can compare.  In my experience, sometimes the 99%/1% DD conditions produce smaller loads than the annual simulation, so you'll want to pay attention to that.

Kristin Field


***************************************************************
Kristin M. Field, EI
Energy Analysis Group
Architectural Energy Corporation
2540 Frontier Ave., Suite 201
Boulder, CO  80301
303.444.4149




>>> Randy Wilkinson <randy at hvacware.net> 1/10/2008 2:17 PM >>>
Sherie and all,

Where I work, we also have been using Trace for decades.  I've used Trace, HAP, and eQuest. for years now.  Here is my take:

eQuest:

Great for quick energy models where room-by-room breakdown of loads and energy use is not required.  

Not very useful for load calculations.  This is what the eQuest training class taught me.  Something about peak load calculations not appropriate (weather data?).  I wish they could fix that.  I'd be tempted to use eQuest for load calculations.

Determine energy impact of improvement measures quickly. 
Energy use reports are pretty and impress everyone. 
Like Brandon said, the 3D views of the building geometry is useful for checking. 
Support is best gotten from this mailing list.  Sometimes questions go unanswered. 
The two wizards to get your model mostly done.

Free!

Trace:

Proven and reliable for loads AND energy study work.

Able to do more detailed zone and room breakdown of load components.  

Output reports seem to be tailored specifically for load calculation and work well for that purpose. 
Energy and load output reports are not pretty, but the experienced users like them. 
The professional support technicians at Trane are excellent and you can get answers fast.

Must start your model from scratch every time (although we hear they are working on a wizard)

Costs a lot of $$$

When we do HVAC design work in conjunction with energy study work, the Project Engineer always wants to use Trace for the energy model.  He will say that because he already has a Trace model and all we need to do is add schedules and energy rates.  It has been my experience that when you have a building model detailed enough for load calculations, it is WAY too detailed for energy modeling.  The Trace energy calculations take too long and are not really more accurate.

5 hours for results on energy modeling is outrageous.  Sounds like a loads model is being used for energy modeling.  Time to re-think.  Even my large eQuest models only take a few minutes to simulate.

Randy

-- 
Randall C. Wilkinson , P.E., C.E.M., LEED A.P., Mechanical Engineer 
v:509.747.2179  f:509.747.2186  i:www.lseng.com
L&S  Engineering Associates, Inc.


Sherie E. Hensley wrote: 
My company has used Trace for many years with the main purpose to calculate loads.  Trace has continued to evolve.  However, with the evolution the program has become more and more detailed for input.  Additionally, the time it takes to calculate results alone can be extremely lengthy (5+ hours with full year weather data).  Now that the need for energy modeling especially for LEED has dramatically increased, I am currently modeling several projects using Trace.  In talking with a few architects and even a third party energy modeler, they are using eQuest.  

I realize there is a learning curve for energy modeling as well as new software.  However, my company is looking for an energy modeling program that allows for straight forward input and reliable/accurate results.

I have downloaded eQuest and spent a few hours looking at the program and capabilities.  At first glance eQuest appears to not be as detailed in its inputs.

Does anyone have any experience with Trace and eQuest?  Pros vs Cons for energy modeling?

Thanks in advance,


Sherie Hensley P.E., LEED AP
Mechanical Engineer



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