For those also subscribed to the bldg-sim list, you may have just seem Eric Sturm's email with an updated spreadsheet comparing DOE2, eQuest, Trace and HAP.
I don't think it's up-to-date for eQuest, but something on the list scared me. eQuest isn't still limited to 1024 zones is it?
I'm working on a 19 story building with 100+ spaces per floor, and I'm hoping this isn't still the case. I thought I remember seeing that since version 3.37, you're allowed to have something like 4000 spaces.
Can anyone confirm? Would really suck to get ? of the way thru my model and realize I have to cut back on zoning.
Thanks!
James Hansen, PE, LEED AP
Hi James,
I can't confirm for you your question about allowable zones, but I did want
to offer a couple of cents from my perspective...I hope that you are not
planning to zone each space for each floor. This is what I call a
simulation nightmare--primarily for you as the simulator, but also for
anyone who is or will be reviewing your model.
The zones are specifically thermal zones, so where you have alike thermal
characteristics you can zone these spaces together as one zone. Be mindful
of zoning like spaces, but different perimeter exposures--for example you
should not create a thermal zone that has both an east & south perimeter
exposure because of the envelope loads that are experienced by these
differing exposures.
Always try to simplify your models to work with as few zones as
possible--from an input & file management standpoint. Remember the more
inputs you have, the more you open the door for variable errors in your
file. Sometimes the fewest possible zones might be in the 100's, or in the
10's range, but I personally would question any model that used more than
1000 zones for anything unless there were extenuating circumstances.
If you'd like some extra assistance or suggestions for your thermal zoning
approach & input into eQuest, please contact me and send me some pdf's of
your floor plans and I would be happy to help you.
Pasha
Thanks Pasha - I forgot to mention that the building I am modeling takes up an entire city block in DC. Hence the large number of zones. I've definitely cut it down to as few zones as I can without potentially sacrificing results.
For reference, this was what Jeff Hirsch sent around about v3.37. I'm assuming it's the same for v3.63, and it looks like you can now model 4000 spaces and 4000 zones (hopefully).
I was just wondering if anyone had evidence that this is the case:
For AutoCAD import and trace around (or just manually created floor plans,
spaces, or surfaces) the maximum number of vertices in 120. This version
also allows up to 4000 spaces and 8000 each for exterior walls, windows and
2000 air-side HVAC systems. A 1440 space run (with 792 exterior walls and 372
windows, 672 ground coupled surfaces, 4080 interior walls, 648 building shades, 720 air-side
AHU's) runs through BDL in 90 seconds and completes a year simulation, including
detail output reports, in just under 51 minutes on a Dell PWS450 (2.66GHz IX
processor and 1GB RAM) running Windows XP-Pro. This model (a 14 building campus)
was created with the new muti-shell, muti-HVAC Design Development wizard in
less than an hour; of course the use of custom footprints and adjustments to space and
HVAC details (needed to represent a final design) will add substantial information collection
and eQUEST input time.
James Hansen, PE, LEED AP
Okay--I would agree that a building the size of an entire city block is an
extenuating circumstance. I wish you luck & sanity on managing this
project.
Keep us posted on how this model works for you, and yes I would assume (like
you) that the zone quantities for V3.37 still do apply for V3.63
Pasha
p.s. I do not envy you for this project--but what a fun challenge
none-the-less. ;)