Put another way:
If you have a perfectly circular floorplate, ASHRAE wants you to model an octagon, with respect to a minimum number of facets.
This specific query reminds me: There was a pretty interesting thought-study presented at ASHRAE's energy conference in 2015 where someone tested this logic, by asking the question (paraphrasing) "how few facets can we get away with and still accurately represent a perfect circle?" I don't recall exactly the answer but the results surprised me with how far you could go in simplifying the shape & still maintain relative accuracy. I believe a 4 sided square (corrected geometrically for volume) in fact performed very closely to the baseline.
If you're sincerely & specifically interested in modeling an octagon as a square, I think you'll find that could actually be pretty accurate so long as you are correcting for conditioned volume / exposed area. I'd seek out that actual paper/presentation while you're at it ;-).
~Nick
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Nick Caton, P.E., BEMP
Senior Energy Engineer
Energy and Sustainability Services
Schneider Electric
D 913.564.6361
M 785.410.3317
E nicholas.caton at schneider-electric.com
F 913.564.6380
15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States
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Attached the presentation slides from reference ASHRAE Conference?..
This project/study had a round building. There is an appreciable improvement in going from 4 side to 8 sides, much (much) smaller improvement in 8 to 12?..but flat lines from there.
Thanks,
DARIC R. ADAIR PE, C.E.M.
Henderson Engineers, Inc.?|?Mechanical Engineer, Energy Analyst
dir 913 742 5530? tel 913 742 5000? fax 913 742 5001? tx id #F-001236? email daric.adair at hei-eng.com? www.hei-eng.com
Licensed in KS.?
Thank you Daric,
Where did you find the paper? I logged on to my ASHRAE account and searched. I found the 2014 & 2016 conference papers but could not locate the 2015 papers.
[Title: RWDI - Description: RWDI logo]
Christopher Jones, P.Eng. | Senior Energy Analyst
RWDI
901 King Street West, Suite 400, Toronto, ON M5V 3H5 Canada
Tel: (519) 823-1311 ext 2052 | Mobile: (416) 697-0056
rwdi.com
I had downloaded it after conference so I had a copy?.unknown where to locate on ASHRAE website.
Let me know if you have any questions.
Thanks,
DARIC R. ADAIR PE, C.E.M.
Henderson Engineers, Inc.?|?Mechanical Engineer, Energy Analyst
dir 913 742 5530? tel 913 742 5000? fax 913 742 5001? tx id #F-001236? email daric.adair at hei-eng.com? www.hei-eng.com
Licensed in KS.?
That?s the one ? thanks Daric!
~Nick
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Nick Caton, P.E., BEMP
Senior Energy Engineer
Energy and Sustainability Services
Schneider Electric
D 913.564.6361
M 785.410.3317
E nicholas.caton at schneider-electric.com
F 913.564.6380
15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States
[cid:image001.png at 01D189AB.58634A10]