# Scoop or no scoop



## minnionn (Jul 29, 2012)

I have an 8"x12" duct coming off my plenum with an interior insulation liner. My question is should the start collars for the round ducts have scoops or doesn't that matter? The collars on now do not have scoops. Do the scoops help air flow? Thanks for your help.


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## scottmcd9999 (Jun 29, 2012)

Are you having troubles with air flow, or just asking a general question?

Scoops can help airflow, but they can also rob air from downstream runs. If the system was not designed with scoops, then in many cases installing them can cause more harm than good.

That said, if you have one or two runs that don't seem to get enough air, and everything else is okay, then adding a scoop to those probably wouldn't hurt (but it may not help, either).


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## minnionn (Jul 29, 2012)

I was having air flow problems in an addition that was added to the house. The addition has a crawl space under it where they ran the duct work. Well I finally got under there to check things out. They had ran flexable duct to vent and had straps of plasic sheeting holding it up. In those places the weight of the duct had compressed the interior. So I removed the flexible duct out and put metal duct in. So far that seems to have helped, but, if it hadn't I thought maybe the collar with the scoop would help.


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## turnermech (Jul 21, 2012)

Most likely your problem comes from adding ductwork to an existing system. this does not work well. the duct system has a set air flow and staic pressure it was designed for. Most people incorectly think you can just add additonal dut to an existing system. even small changes require re-design of the system and in most cases increasing the size of the unit.


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## minnionn (Jul 29, 2012)

I didn't add duct work. The addition was added years ago before I even bought the house. All I did was replace the flexible duct with metal.


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## turnermech (Jul 21, 2012)

you may not have added the duct work but someone did. if it is an addition most likely the original system was tapped into for the addition. It would not matter who did it. If thats what happened it is your problem.


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