Air flow around the 90 degree ell

This one compares 2 different designs of ells in the low pressure duct system.

[IAW]

I wasn't looking for this but i learned something new. Thanks

[gwman]

Thanks for the video. A lot of your knowledge seems like it would be useful to the PC building community. I found this one while researching airflow as it relates to the side mounted fans in a Lian Li PC-O11 Dynamic Case.

[paulliang]

As a CFD engineer, I approve his design.

[stevesloan]

15 years ago I seen on TV footage of the world longest at the time in scale to the longest wind tunnel on Earth. It was in Australia and that’s why I remember it.

[rodgraff]

In the apprenticeship school where I taught, we had a training film that used a bubble generator to determine which types of fittings were the most efficient. Some made the bubbles tumble, and some had very linear airflow.

[carmelpule]

I would not be surprised if the vortex in the upper left-hand corner goes the other way, that is anticlockwise and not clockwise.

[alainhachey]

Does that mean I'm better to place my 90 degree turn a bit after the fan so that the head of the inline fan doesn't start in the middle of the turn. So does adding 3in after the fan and then! turning help keep my pressure. I tend to think that a corner just after the fan(in the turn) creates a wall effect(bad) or is half a turn(good). I know turning right away is better for duct length. Question: Do i add 3in straight and then turn, or turn right away.

[TerryPullen]

Good explanation. I had no idea but you made it seem obvious.

[Ninjump]

This was a great video to help me understand, thank you! I'm designing a system with a small ERV and by this logic seems like PVC piping all my exhaust and return air runs would take all the losses way down?

[noahoyeah]

On the turning vanes. Do we add one vane per slot on the rail or every slot

[mwmccahren]

I have a misalignment at a flange preceding a 90 degree ell (in an industrial engine exhaust passageway). Would a sharp step causing turbulence on the "inside" edge before your ell with the sharp inside corner compound the problem? I'm looking for the root cause of a 20% loss of flow. my new exhaust manifold has a step on the inside edge - opposite of the location of the step of the previous manifold (outside edge).

[esotericman]

First of all, thanks for all your videos on HVAC. My question is, what percentage of air flow is lost for each rounded inner and outer 90 degree bend?

[kishoreinhere]

nice video. will chamfering the elbow result in lower pressure drop? It saves some material also. TY

[Iceburgthagreat]

@grayfurnaceman can you do some more videos on duct design and using manual d and ductualator in calculating duct size and transitions

[PedroGomez-bdro]

John Madden could not have done better

[b.real.]

I'm thinking the air will flow better if the top and the bottom had a curve