[Equest-users] Using eQuest for system sizing and equipment selection

[Seun Odukomaiya]

Hello all,
Has anybody successfully used eQuest to size systems? Having used both eQuest and Trace, I have found that they tend to be in relative agreement when it comes to load estimating. They differ, however, when it comes to sizing systems. Up until now, I have been very reluctant to trust eQuest for sizing equipment, and tend to revert back to Trace. I am wondering, however, if anyone has ever sized equipment based on eQuest outputs.

For example,  I have a simple VAV project with terminal reheat that I modeled both in Trace and eQuest. The SV-A report in eQuest gives me heat capacity values for the terminal boxes that are all within 5% or so of the values I get from Trace for the same zones. This gives me some confidence, going forward, that I can make VAV box selections based on the SV-A output from eQuest.

When it comes to the central station air handler, however, I find that when looking at the SS-A and SS-B reports, the peak loads reported for the preheat and main cooling coils, are dramatically different that those reported by Trace for the exact same project. In trying to size the main Preheat and Cooling coils, I find that the eQuest values are nowhere near the Trace values. My manual calculations, however, tend to be close to the Trace results, but nowhere near the eQuest results. Am I looking at the right reports, or is there a different report that gives me the peak load on my AHU main preheat and cooling coils?

Ultimately, I would like to get to the point where I can solely use eQuest for projects that I know will be submitted for LEED. Right now, I have been using Trace for design, and eQuest for energy modeling. I guess I'm curious to see if anyone has been able to do away with Trace entirely, and rely only on eQuest for design and energy modeling. Any comments, opinions, etc would be greatly appreciated.

Seun Odukomaiya, LEED AP  -  Mechanical Engineer
L'Acquis Consulting Engineers
280 East 96th Street, Suite 280
Indianapolis, IN 46240
voice:  (317) 706-2075
fax:     (317) 706-2076
email:  sodukomaiya at laceindy.com<mailto:amaue at laceindy.com>
web:  www.laceindy.com<http://www.laceindy.com>
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