[Equest-users] Oversized cooling

Joe Huang yjhuang at whiteboxtechnologies.com
Wed Nov 26 13:04:57 PST 2014


Without looking at the DOE-2.2 input and output files, it's difficult to 
give you a definitive answer, but from my experience explanations for 
such sizing questions can always be found with a little digging and 
understanding of how DOE-2 does autosizing.

When DOE-2 does autosizing, it takes the maximum loads reported from 
LOADS and calculates the equipment capacity (heating, cooling, and fan) 
needed to meet those loads. The fact that the building is in a cool 
climate (Colorado Springs) has  several implications on the sizing 
calculation - (1) fan size is probably determined by the maximum 
heating, not the cooling, load, (2) fan size will also be increased 
significantly (1.24) due to the altitude, (3) substantial difference 
between the peak cooling load from LOADS and SYSTEMS, since the former 
is derived at a constant reference temperature with no outside air, 
while the latter is derived at the actual zone temperature and with 
outside air (e.g., economizer running earlier in the day, etc.).   To 
trace these differences, compare the peak loads in the LOADS reports to 
those in the SYSTEM reports.

Joe

Joe Huang
White Box Technologies, Inc.
346 Rheem Blvd., Suite 205A
Moraga CA 94556
yjhuang at whiteboxtechnologies.com
http://weather.whiteboxtechnologies.com for simulation-ready weather data
http://www.whiteboxtechnologies.com
(o) (925)388-0265
(c) (510)928-2683
"building energy simulations at your fingertips"


On 11/25/2014 11:18 AM, Sami, Vikram wrote:
>
> Curious.
>
> I do think the higher load seems to be more like what you should 
> expect for a building this size (7501 kBTU/h = 625 tons. For a 102,000 
> ft2 building that’s 163 ft2/ton). That might be slightly oversized for 
> Ft Carson, although Colorado springs gets hot in the summer. Not sure 
> what your building loads are, but 163 ft2/ton is not unheard of for a 
> heavy use building. I would expect something more in the range of 
> 250-300. So the question is why is the maximum cooling load reporting 
> as only 927 kBTU/hr (77.25 tons = 1320 ft2/ton)
>
> Just my two cents from looking at this for five minutes – I might be 
> wrong.
>
> *Vikram Sami*
> BEMP, LEED BD+C
> Associate Partner
>
> 	
>
> 	
>
> ZGF ARCHITECTS LLP
> *T *206.521.3509 *E *vikram.sami at zgf.com
> 925 Fourth Avenue, Suite 2400
> Seattle, WA 98104
>
> *From:* Equest-users 
> [mailto:equest-users-bounces at lists.onebuilding.org] *On Behalf Of 
> *Gonzalo Lema
> *Sent:* Monday, November 24, 2014 12:25 PM
> *To:* equest-users at lists.onebuilding.org
> *Subject:* [Equest-users] Oversized cooling
>
> Hi,
>
> I have a problem with the cooling capacity. The Max cooling load is 
> 927 kbtu/hr, but the cooling capacity is 7501 kbtu/h. I auto-sized the 
> equipment (system and cooling coil) for 1.00, but I don’t understand 
> why the factor seems to be 8x.
>
> The system fan Works in part-load 0-20% all the time:
>
> Does anybody knows what could be causing this?
>
> **
>
> Thanks.
>
> **
>
> *SUMAC*
>
> *Gonzalo Lema | Mechanical Engineer | LEED GA*
>
> Tel: +1.773.857.7906 Ext 7009 (Chicago, USA)
>
> Tel: +1.305.814.8805 (Miami, USA)
>
> Tel: +511.253.5355 (Lima, Perú)
>
> Tel: +593.4.600.0613 (Guayaquil, Ecuador)
> Tel: + 571.3151985 (Bogotá, Colombia)
>
> glema at sumacinc.com <mailto:glema at sumacinc.com>
>
> www.sumacinc.com <http://www.sumacinc.com/>
>
> *From:* Dante Garcia
> *Sent:* Monday, November 24, 2014 10:24 AM
> *To:* Gonzalo Lema
> *Subject:* RE: eQuest - Fort Cartson
>
> Hola Gonzalo,  no he podido encontrar el error hasta el viernes que 
> estuve avanzando.
>
> Ahora he estado con otras prioridades, mañana puedo volver a revisar 
> el proyecto.
>
> Saludos,
>
> Dante
>
> *SUMAC*
>
> *Dante Garcia, LEED AP BD+C | Analista LEED Energía*
>
> Tel: +511.253.5355 Anexo 16 (Lima, Perú)
>
> Cel: +51.989.685.769 (Lima, Perú)
>
> Tel: +593.4.600.0613 (Guayaquil, Ecuador)
> Tel: + 571.3151985 (Bogotá, Colombia)
>
> Tel: +1.773.857.7906 (Chicago, USA)
>
> dgarcia at sumacinc.com <mailto:dgarcia at sumacinc.com>
>
> www.sumacinc.com <http://www.sumacinc.com/>
>
> *De:*Gonzalo Lema
> *Enviado el:* lunes, 24 de noviembre de 2014 11:17 a.m.
> *Para:* Dante Garcia
> *Asunto:* RE: eQuest - Fort Cartson
>
> Buen día,
>
> ¿Alguna novedad?
>
> Yo sigo revisando también.
>
> Saludos
>
> *SUMAC*
>
> *Gonzalo Lema | Mechanical Engineer | LEED GA*
>
> Tel: +1.773.857.7906 Ext 7009 (Chicago, USA)
>
> Tel: +1.305.814.8805 (Miami, USA)
>
> Tel: +511.253.5355 (Lima, Perú)
>
> Tel: +593.4.600.0613 (Guayaquil, Ecuador)
> Tel: + 571.3151985 (Bogotá, Colombia)
>
> glema at sumacinc.com <mailto:glema at sumacinc.com>
>
> www.sumacinc.com <http://www.sumacinc.com/>
>
> *From:* Gonzalo Lema
> *Sent:* Friday, November 21, 2014 5:52 PM
> *To:* Dante Garcia
> *Subject:* RE: eQuest - Fort Cartson
>
> Como va?
>
> Encontraste algo mas?
>
> Buen finde.
>
> *SUMAC*
>
> *Gonzalo Lema | Mechanical Engineer | LEED GA*
>
> Tel: +1.773.857.7906 Ext 7009 (Chicago, USA)
>
> Tel: +1.305.814.8805 (Miami, USA)
>
> Tel: +511.253.5355 (Lima, Perú)
>
> Tel: +593.4.600.0613 (Guayaquil, Ecuador)
> Tel: + 571.3151985 (Bogotá, Colombia)
>
> glema at sumacinc.com <mailto:glema at sumacinc.com>
>
> www.sumacinc.com <http://www.sumacinc.com/>
>
> *From:* Dante Garcia
> *Sent:* Thursday, November 20, 2014 5:21 PM
> *To:* Gonzalo Lema
> *Subject:* eQuest - Fort Cartson
>
> Gonzalo, te envío el eQuest que revisé, todavía no encuentro el error, 
> solo edité un poco el primer piso ya que dos zonas se sobreponían, 
> mañana seguré revisando y ver si encuentro algo, una consulta, viste 
> este reporte, así son los cfm que deben tener cada zona o es bien alto?
>
> Saludos,
>
> Dante
>
> *SUMAC*
>
> *Dante Garcia, LEED AP BD+C | Analista LEED Energía*
>
> Tel: +511.253.5355 Anexo 16 (Lima, Perú)
>
> Cel: +51.989.685.769 (Lima, Perú)
>
> Tel: +593.4.600.0613 (Guayaquil, Ecuador)
> Tel: + 571.3151985 (Bogotá, Colombia)
>
> Tel: +1.773.857.7906 (Chicago, USA)
>
> dgarcia at sumacinc.com <mailto:dgarcia at sumacinc.com>
>
> www.sumacinc.com <http://www.sumacinc.com/>
>
> ZGF Email Disclaimer <https://www.zgf.com/ZGF_Email_Disclaimer.html>
>
>
>
> _______________________________________________
> Equest-users mailing list
> http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20141126/9699cc01/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 43505 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20141126/9699cc01/attachment.jpeg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/png
Size: 20625 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20141126/9699cc01/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/png
Size: 39268 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20141126/9699cc01/attachment-0001.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 36650 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20141126/9699cc01/attachment-0001.jpeg>


More information about the Equest-users mailing list