structure versus duct or other designations?
structure has the depth first e.g. W12x36 and duct puts it last e.g. 14 x 6?
i’ve never thought about it like this but the first number on the structure is depth? and the second number in ducts is depth?
why do ducts put the second number as depth when you think that is what people would be concerned with first?
also, are there other architectural elements in the exams that /don’t/ put depth first?
THANKS
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Yes, a W12x36 is a 12" deep beam. The second number 36 I believe is the weight of the beam in lbs/ft, which you should not need to know for the test, but there you go. Stretching back to my structures classes many years ago on that one, might be misremembering it......could also be the load it can take per foot but I don't think that's right...........doesn't matter.
And yes, a 14 x 6 duct is 6" deep. 14" wide.
Can't think of anything else that is like this. Not sure what to say regarding why they do it other than they just do!
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thanks david.
appreciate the help.
someone elsewhere mentioned ducts are listed (like windows and doors presumably) width first to emphasize how much structure you are (or may be) taking out.
windows and doors needing a header and steel beams presumably having some nothing or something.
this seems to make sense with windows and doors but with ducts i would think you would also be concerned about how much you were also taking out vertically in height.
so maybe it is actually for the spacing of the beams to be able to easily identify conflicts in plan. or maybe for air flow there is a reason to see width first or both.
sort of off topic otoh it seems silly to get a question wrong for mistaking the order if duct sizing to be. -
Hi All,
For the community's sake I would like to clarify that David's first comments about structural members' second number designation was correct. It is the weight of the beam. I would like to respectfully disagree with the statement that candidates do not need to know this.
The weight of the beam is essential for member calculations and load tracing exercises which may be encountered in this exam.
All the best,
Kevin Griendling, AIA
xq.intersectartsstudio.com
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Jonathan,
In my honest opinion, flange depth, web thickness, etc. are all metrics primarily used for calculations that are beyond the scope of this exam, and the architect's general scope of liability.
For these exams candidates really only need to know the MATH for:
- Simple span and cantilever beam forces
- ...for shear
- ...for moment
- Load tracing
- Maybe brush up a bit on truss calculations, but if you lack time, don't sweat it.
Hope this helps,
Kevin Griendling, AIA
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