Bldg Area in BEPS/BEPU

5 posts / 0 new
Last post

Hello all,

I recently completed a project and while going through the QC process I
noticed that the building area as reported on the BEPS/BEPU reports does
not match up with the model input. I have looked through the various
other reports and the building square footage appears to be modeled as
designed. I think the culprit might be unconditioned spaces but when I
change these spaces to conditioned the problem still persists. Does
anyone have any suggestions where to start trouble shooting or which
report might tell me where the discrepancy is. The reported area is off
by 15% on the BEU/BEPS reports.

Thanks in advance for your help.

Seth P Spangler, PE, LEED AP BD+C

Tiger06's picture
Offline
Joined: 2011-02-14
Reputation: 0

Dear Seth,

I realized the same problem due to a review comment from GBCI. I was
able to modify the net area values (actually only the MBTU/net area
value, as only this is displayed in the reports) by changing the
conditioned - unconditioned - plenum status of the spaces (be careful,
not the thermal zones, but the spaces). I do not know anything about the
MBTU/gross area value, since this is displayed as INF in my case
(meaning infinity? meaning I have infinite energy consumption ? :))

Hope this helps,

Omer Moltay

21.06.2011 14:49, Seth P. Spangler yazm?s,:

Omer Moltay's picture
Offline
Joined: 2011-09-30
Reputation: 0

The BEPS/BEPU reports are based on the gross floor area, which, unless directly input in the dialog box "Building Properties" (see enclosed illustration), defaults to the sum of the conditioned spaces.

So, if you input nothing in said dialog box, playing with your unconditioned spaces might do the trick.

[cid:image001.png at 01CC2FFD.E593C5C0]

_________________
Demba NDIAYE

Demba Ndiaye's picture
Offline
Joined: 2011-09-30
Reputation: 200

Not that this might be your problem, but i once had a model that i couldn't
figure out why i had such a different area than what i initially modeled. I
ended up finding out that the "dummy" space that my DOAS was feeding OA to
was defaulted to be rather large and this caused my Area to inflate. After
making this space a box of 0.1 x 0.1, it was able to work much better and
get the results i expected to see on these reports.

Rob

2011/6/21 Demba Ndiaye

--
Rob Hudson

rdh4176's picture
Offline
Joined: 2011-02-14
Reputation: 0

Thanks for the responses everyone.

Omer led me in the right direction but I had to change different parameters.

Under the Building Shell tab I changed the space setting to be "conditioned" for all spaces that were listed as "unconditioned" with the exception of the plenum spaces - these I left alone. Previously I was changing the HVAC zones without any results. I did not change anything under the HVAC tabs and the spaces remained as "unconditioned" from an HVAC standpoint. By doing this the BEPS/BEPU and LS-C reports all show the correct building area without affecting the building energy consumption. Review of the LPD and process loads confirms the spaces are modeled for energy analysis and now all reports are showing the correct area.

Thanks again for the help.

Seth P Spangler, PE, LEED AP BD+C

Tiger06's picture
Offline
Joined: 2011-02-14
Reputation: 0