eQuest 7175 DOE2.3 Simulation Speed

4 posts / 0 new
Last post

Hi All,

I always read everyone's posts but have never posted. Thank you for all of
the informative exchanges over the years.

I have been using the 7175 DOE2.3 version of eQuest since it was released
and have found the simulation times to be significantly greater than the
7173 DOE2.2 build (even with creating the heating and cooling design days
in detailed mode). I'm wondering if anyone else has experienced this, and,
if so, if you have found a way to speed up simulation times. In smaller
models (~50,000 sf) it is not a big deal but with larger models (~350,000
sf+) I find that it impacts productivity greatly.

Any input would be appreciated.

Thanks!

Christina

*Christina LaPerle* PE, BEMP, CEM, CBCP
Senior Energy Engineer
________________
Karpman Consulting
Phone 860.266.6220

Christina LaPerle's picture
Joined: 2019-12-11
Reputation: 0

Christina,

One quick fix we have found is to make sure to specify Design Days for both cooling and heating. On the ?Project & Site? tab, right click the project name at the very top of the component tree and then select ?Create Design Day? and enter the design temperature information. You?ll need to do this twice to cover cooling and heating design conditions. This reduces simulation time by a fair amount as it seems to cut down on the repeat load calculations that run in 7175 without design day conditions specified. We have still observed longer run times in general, but this helps.

Thanks,

Coles Jennings PE, BEMP, LEED AP BD+C
Sr. Energy and Sustainability Engineer | Mason & Hanger
A Day & Zimmermann Company
O 804.521.7045
4880 Sadler Road, Suite 300 | Glen Allen, VA 23060
masonandhanger.com

An ISO 9001 Certified Company

Building a More Secure World ?

CAUTION - THIS EMAIL MAY CONTAIN CONFIDENTIAL INFORMATION

This electronic mail transmission and any accompanying documents may contain information belonging to the sender, which may be proprietary, confidential, and/or otherwise subject to restrictions on disclosure beyond the intended recipient. This information is intended only for the use of the individual or entity to whom this electronic mail transmission was sent as indicated above. If you are not the intended recipient, any disclosure, copying, distribution, or action taken in reliance on the contents of the information contained in this transmission is strictly prohibited. If you have received this transmission in error, please call 1-703-955-5702 and delete this transmission. Thank you.

Jennings, Coles's picture
Offline
Joined: 2017-10-20
Reputation: 0

Thanks Cole but already doing that and still experiencing slow run times.

*Christina LaPerle* PE, BEMP, CEM, CBCP
Senior Energy Engineer
________________
Karpman Consulting
Phone 860.266.6220

On Thu, Dec 10, 2020 at 10:11 AM Jennings, Coles <

Christina LaPerle's picture
Joined: 2019-12-11
Reputation: 0

Hi Christina!

Thank you for your sustained viewership, and welcome to the conversation!

You aren?t seeing things: doe2.3 operated through the eQuest interface definitely feels more ?weighted? than prior versions or operating with the doe2.2 engine. I think design-day definitions are the only ?universal? action I?ve discovered that can improve simulation run times specific to eQuest v1765, with doe2.3.

There may be other general efficiency fixes/potential specific to your model, of course. As with any simulation platform/version, sometimes the inputs need to adapt to the tool. A couple hours invested into stripping unused components, and pulling back on the resolution (simplifying) for very detailed schedules, geometries, and on occasion ?heavy? expressions can yield meaningful gains in simulation time. Sometimes breaking a very complex model into two or more smaller chunks is a smart call. With any efficiency/optimization efforts, remember to consider and occasionally re-evaluate the potential benefits of simulation savings time against the extra hours invested into polish/streamlining?

Energy simulation is one of those neat skillsets where human and machine strengths come together to accomplish something neither could do alone. As you pursue optimization of the machine, don?t forget the human that runs the machine. After some degree of hammering away at a long simulation runtime, it becomes more efficient/healthy (for man and machine together) to just take a coffee break, stare out the window, and introspect for a bit during the workday!

Okay so off of my soapbox, I have one more thought which is probably a little more constructive? If you are in a real pinch and the simulation load is heavy (this is not universal advice): Command line doe2 is (as it has always been in my career) substantially faster than loading a model, simulating, and reloading in between each simulation through the eQuest interface. I don?t leverage that option often myself, but if you ever have some situation with the need to crunch tens/hundreds/thousands of simulations, then I strongly-to-emphatically encourage exploring the command line option!

If scripting command line simulations is new territory for you or anyone else, here is a potentially helpful reference on unmethours where I shared a developed/working Python 2.7 script specific to eQuest/doe2. Check out the original prompt ,and contributions by others to pick up a few ways to tackle this sort scripting effort: https://unmethours.com/question/4668/script-for-multiple-simulations/?answer=13310#post-id-13310

~Nick

[cid:image001.jpg at 01D6CF8E.E5A94630]
Nick Caton, P.E. (US), BEMP
??? ????, P.E. (US), BEMP
Senior Energy Engineer
Energy Manager, Yokota Airbase
ESS - Energy & Sustainability Services
M JP
M US
Email
+81 . 070 . 3366 . 3317
+1 . 785 . 410 . 3317
nicholas.caton at se.com
?????????????
???????????????
ESS - ?????????????

[cid:image002.png at 01D6CF8E.E5A94630]
[cid:image003.png at 01D6CF8E.E5A94630]
[cid:image001.jpg at 01D6CF8E.E5A94630]

Nicholas Caton2's picture
Offline
Joined: 2019-03-25
Reputation: 0