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FLEXIBLE DUCT FOR PLENUM CONNECTION???

FLEXIBLE DUCT FOR PLENUM CONNECTION???

FLEXIBLE DUCT FOR PLENUM CONNECTION???

(OP)
Hello Everybody!
Good Day!!!
With reference to the subject I am dealing with duct work on site wherein I found discrepancy in the design & its as follows:
A DUCTED FCU of capacity 396 l/s with a duct size 700X150mm & the distribution of air to the living/dinning room is via a Diffuser(225x225mm-50 l/s= 2Nos) & a Linear Air bar grille of size 1500x100mm for 296 l/s air flow. The designer has selected 200mm flexible duct to connect it with the Plenum of linear bar grille in 4 Nos of multiple connections whereas the Main rectangular duct height itself is 150mm, hence I can't fix 200mm flex duct in a 150mm height of duct. illogical!

At this moment I cant even re-size the main rectangular duct as all the shop drawings are processed for duct fabrication.
Should I go for a 100mm flexible duct by increasing the Nos of multiple connections or I need to increase the size of a plenum?

I am worried about Noise levelmad.

Please advice. Your comments are highly appreciated.


Thanks in advance.

RE: FLEXIBLE DUCT FOR PLENUM CONNECTION???

Can't you connect the flexible 200 mm duct to the top of 700x150 mm duct instead of the side?

RE: FLEXIBLE DUCT FOR PLENUM CONNECTION???

You should be submitting this question in the form of an RFI and possible change order to your designer of record. He will need to sign-off on any deviations from plan.

RE: FLEXIBLE DUCT FOR PLENUM CONNECTION???

(OP)
dbill74 you are correct. I sent them a RFI but our consultant is damn good you know....After trying that I posted here.


@317069 (Mechanical) I think its ok. but if I connect flex from the top then the balancing(round)damper will be in a vertical position which is again a issue.
And also the flex duct will be in a C-Shape.

I will check once....or else I will resize the plenum.


Thanks all.

RE: FLEXIBLE DUCT FOR PLENUM CONNECTION???

You should be able to make a side takeoff rectangular to round transition with a 45* entry. Have them make it 150mm on the side then transition to 200mm round.

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