Ductwork Best Practices

[treits]

I came across an installation today that I have not seen before. A round tap was installed directly on a radius elbow, since I have not seen this before I am curious if this is considered acceptable practice or if there may be airflow or noise issues as a result. Any opinions would be appreciated.

 

[berkshire]

It is called a heel tap, It is not considered good practice, but every once in a while it has to be done. Normally if you, have, to do it. You try to offset the tap in the direction of the flow .
Good practice dictates that unless there is no other way, all fittings shall come off the straight duct.
I once got painted into a corner on a duct design , and ended up having to use a heel tap, My boss saw it and went ballistic , took the job away from me , then spent two days trying to re-draw the project without success, He finally gave it back to me and said , " Ok you can use it, but just this once.", so as you see it is not a popular solution.
B.E.

You are judged not by what you know, but by what you can do.

 

[Drazen]

that is typical issue of contractor that has no even tiny sheet metal workshop able to make some custom-made fittings.