[Bldg-sim] Walk-in Coolers/Freezers

[Martin Roy]

Hi Kurt,

We model a refrigerated warehouse using ESPr and 
TRNSYS.  We did not try Energy+.
The main reason was to evaluate the effect of the 
thermal mass stored against the incoming product that was warmer.
when we compare our result to those of the 
refrigeration contractor there was a big 
difference.  Half of their calculated load
And compare to actual energy consumption, it was close.

So if you use energy+ be shure to include thermal mass.

Martin



At 15:00 26/05/2011, Jeff Haberl wrote:
>Kurt,
>
>We had this problem before in the mid-80s 
>simulating an ice rink at a Rec Center. This was 
>published in an ASHRAE Transactions paper. We 
>basically got around the issue by fudging the "U 
>x A x Delta-T"...in this case fiddling with 
>either the U or the A to adjust for the Delta-T. 
>Results worked well against metered data.
>
>Jeff
>
>8=!  8=)  :=)  8=)  ;=)  8=)  8=(  8=)  8=()  8=)  8=|  8=)  :=')  8=)8=?
>
>Jeff S. Haberl, Ph.D.,P.E., FASHRAE..............jhaberl at tamu.edu
>
>Professor............................................................Office 
>Ph: 979-845-6507
>
>Department of Architecture.............................Lab Ph:979-845-6065
>
>Energy Systems Laboratory.............................FAX: 979-862-2457
>
>Texas A&M University.....................................77843-3581
>
>College Station, Texas, USA, 77843..................URL:www.esl.tamu.edu
>
>8=/  8=)  :=)  8=)  ;=)  8=)  8=()  8=)  :=)  8=)  8=!  8=)  8=? 8=)8=0
>________________________________________
>From: bldg-sim-bounces at lists.onebuilding.org 
>[bldg-sim-bounces at lists.onebuilding.org] on 
>behalf of kcreamer at nc.rr.com [kcreamer at nc.rr.com]
>Sent: Monday, May 23, 2011 9:19 PM
>To: bldg-sim at lists.onebuilding.org
>Subject: [Bldg-sim] Walk-in Coolers/Freezers
>
>Hi all,
>
>Is it possible to use EnergyPlus to model a 
>walk-in cooler or freezer?  I have tried but 
>regardless of the temperature setpoint I choose 
>for the freezer, the modeled temperature does 
>not want to drop below about 42 F.
>
>Also, has anyone made a model of a cooler that 
>accurately estimates electricity loads?  I was 
>able to model a cooler with a 45 F setpoint but 
>I was way under the electricity consumption 
>estimates I found for coolers/freezers on the 
>web.  I think my problem was the large amount of 
>electrical usage for non-compressor loads ­ 
>defrost cycle, evaporator fan, condenser fan, etc.
>
>Kurt Creamer
>Apex, NC
>
>_______________________________________________
>Bldg-sim mailing list
>http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
>To unsubscribe from this mailing list send  a 
>blank message to BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
>_______________________________________________
>Bldg-sim mailing list
>http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
>To unsubscribe from this mailing list send  a 
>blank message to BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG


----------

Martin Roy, ing. PA LEED®, président
Martin Roy et associés
1805 chemin Oka,
Deux-Montagnes, Qc
J7R 1N3


Tel: 450-623-0340
Cell. 514-594-6352

www.mra.qc.ca






Message de confidentialité
Ce courriel (de même que les fichiers joints) est 
strictement réservé à l'usage de la personne ou 
de l'entité à qui il est adressé et peut contenir 
de l'information privilégiée et confidentielle. 
Toute divulgation, distribution ou copie de ce 
courriel est strictement prohibée et peut être 
l’objet de poursuites judiciaires. Si vous avez 
reçu ce courriel par erreur, veuillez nous en 
aviser  et le supprimer de votre système 
informatique sans l'imprimer, le copier ou le faire suivre a quiconque.

Devez-vous vraiment imprimer ce courriel ?  Pensons environnement...
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20110526/3dea4455/attachment-0002.htm>