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Distinguished Contributor
jmcfaddn
Posts: 399
Registered: ‎12-01-2003
Message 1 of 8 (489 Views)

Flex duct Problems.

489 Views, 7 Replies
07-07-2003 12:10 AM
I'm trying to add flex duct to connect my diffusers to my low pressure ductwork. If I use hard round ductwork everything works fine and looks good. If I try to perform the exact same inputs using flex, the ductwork shoots way out to no where land and comes in all messed up. Is there any special requirement when adding flex duct from a diffuser to hard rectangular ductwork? Has anyone been able to due this successfully?
Valued Contributor
advandes
Posts: 90
Registered: ‎12-10-2003
Message 2 of 8 (489 Views)

Re: Flex duct Problems.

07-07-2003 09:02 PM in reply to: jmcfaddn
I have had the same problem many times and the only solution I have found so far is once you have selected the connection point for the start of the flex duct, pick another point to continue placing the flex, and then select the diffuser. For some reason the routine does not function when selecting only 2 points (take-off to diffuser). I hope this helps....Aaron
Aaron A. Gray
Advance Design
369 Sagamore Drive
Rochester, NY 14617
585-734-8277
Distinguished Contributor
jmcfaddn
Posts: 399
Registered: ‎12-01-2003
Message 3 of 8 (489 Views)

Re:

07-07-2003 10:08 PM in reply to: jmcfaddn
Yes, that is what I was trying and actually got worse results than connecting directly to the ductwork.
Valued Contributor
advandes
Posts: 90
Registered: ‎12-10-2003
Message 4 of 8 (489 Views)

Re:

07-08-2003 01:06 AM in reply to: jmcfaddn
Hmmm, so my suggestion did not work for you? I am not sure what you meant by "connecting directly to the duct". Are you connecting from the diffuser to the duct? I am assuming you have a tap in the side of a main duct run and want to connect from the tap to the diffuser. I have also played around with the Flex Duct settings in the Duct Preferences dialog and changed the radius curve to 1 and the segment mode to arc......good luck!....Aaron
Aaron A. Gray
Advance Design
369 Sagamore Drive
Rochester, NY 14617
585-734-8277
*[Autodesk], Kevin Mak
Message 5 of 8 (489 Views)

Re: Flex duct Problems.

07-09-2003 12:39 AM in reply to: jmcfaddn
Hi Jody,

 

Aren't you using spline mode flex duct for
connection? Connect with arc flex segment will get odd
results like yours in this case. If you are using spline segment, please
check the osnap settings and make sure it's "osnapping" to the correct
duct or connector when connecting from diffuser, especially when you have
overlapping ductworks. If it still doesn't work for you, would you
mind sending me the drawing so that I can take a look?

 

Thanks,

 

Kevin Mak [Autodesk]


style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
I'm
trying to add flex duct to connect my diffusers to my low pressure ductwork.
If I use hard round ductwork everything works fine and looks good. If I try to
perform the exact same inputs using flex, the ductwork shoots way out to no
where land and comes in all messed up. Is there any special requirement when
adding flex duct from a diffuser to hard rectangular ductwork? Has anyone been
able to due this successfully?
Distinguished Contributor
jmcfaddn
Posts: 399
Registered: ‎12-01-2003
Message 6 of 8 (489 Views)

Re:

07-09-2003 03:32 AM in reply to: jmcfaddn
To put it bluntly, the spline routine is a piece of (edited).
Have you ever taken a tube and twisted it? The throat will deform choking off the clearance inside. That's exactly what that spline routine does. The ductwork does not hold its shape. At certain points on a 10"dia. duct it looks like its almost flat and have 2" of clearance.
*[Autodesk], Kevin Mak
Message 7 of 8 (489 Views)

Re:

07-09-2003 05:27 AM in reply to: jmcfaddn
Jody,

 

There is a display problem on spline flex duct. We
know about it.

 

Kevin Mak [Autodesk]


style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
To
put it bluntly, the spline routine is a piece of (edited).
Have you ever
taken a tube and twisted it? The throat will deform choking off the clearance
inside. That's exactly what that spline routine does. The ductwork does not
hold its shape. At certain points on a 10"dia. duct it looks like its almost
flat and have 2" of clearance.
*[Autodesk], Kevin Mak
Message 8 of 8 (489 Views)

Re:

07-09-2003 05:34 AM in reply to: jmcfaddn
It seems to happen when the connection
is very close to the end of the duct. There is a simple work-around
for this problem: Turn ORTHO on, select the endcap and the rectangular
duct, grab the endpoint and extend the duct (lengthens it!!). Then I will be
able to make the flex duct connection without any problem. After the connections
are done, bring the endpoint of the duct and the endcap back to the original
location. Hope this helps.

 

Kevin Mak [Autodesk]


style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

Hi Jody,

 

Aren't you using spline mode flex duct for
connection? Connect with arc flex segment will get odd
results like yours in this case. If you are using spline segment, please
check the osnap settings and make sure it's "osnapping" to the correct
duct or connector when connecting from diffuser, especially when you have
overlapping ductworks. If it still doesn't work for you, would you
mind sending me the drawing so that I can take a look?

 

Thanks,

 

Kevin Mak [Autodesk]


style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
I'm
trying to add flex duct to connect my diffusers to my low pressure ductwork.
If I use hard round ductwork everything works fine and looks good. If I try
to perform the exact same inputs using flex, the ductwork shoots way out to
no where land and comes in all messed up. Is there any special requirement
when adding flex duct from a diffuser to hard rectangular ductwork? Has
anyone been able to due this
successfully?

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