[Equest-users] Roof conduction

[Brian Fountain]

Shalini,

I have not looked at the model but the issue will be that you have 
defined a plenum.  The LS-C report is showing only conditioned spaces -- 
this is good because the area for plenums & unconditioned spaces are not 
included in the area shown in LS-C -- but it does lead to the result you 
are seeing -- unconditioned & plenum area conduction losses are not 
included.

The next logical question is why isn't is then shown in the LS-C as an 
internal wall conduction loss through the ceiling to the plenum.  In the 
Loads portion of the program, it does not know what the space 
temperatures are as those are based on the setpoints which are defined 
as schedules in the system portion of the program.  So, it uses the 
space design temperature as an initial estimate.  Typically, this 
temperature is the same for the plenums and the spaces -- so no internal 
heat transfer in the LS-C and other Loads level reports.

In the system run, the plenum temperature does drop and the impact of 
roof insulation is calculated.  You can convince yourself of this by 
changing the roof R-value and seeing the impact.

Hope this helps.

Brian



On 5/31/2011 3:03 PM, Shalini Modi wrote:
> Dear all,
>
> I need to check and document the heat loss and gain through various 
> components on the building envelope. Checking the report LS-C for the 
> same, my building reports to have zero heat loss or gain due to roof 
> conduction. If someone can have a look at my model (attached herewith) 
> and advice what the problem could be, that will be greatly appreciated.
>
> Thanks,
>
> Shalini
>
>
> _______________________________________________
> 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
>
>
> No virus found in this message.
> Checked by AVG - www.avg.com <http://www.avg.com>
> Version: 10.0.1375 / Virus Database: 1509/3671 - Release Date: 05/31/11
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20110531/da381d3d/attachment-0002.htm>