# Air flow and coil placement in an RDA



## Gonzilla (13/11/17)

A long video but I found it really interesting, he builds up a mock RDA to test airflow and coil placements. Even runs through some specific RDA's and tests different air slots. 

Results seem to indicate having your coils directly opposite where the air enters your coil chamber has the best results. Gonna have to test the theory next time I rebuild.

Reactions: Like 2 | Winner 1 | Informative 6


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## Rude Rudi (13/11/17)

Wow, what a revelation! It’s a case of just doing what the clever lad at the vape store tells us but this PROVES the opposite. Besides decent coils, coil placement is vital, based on the evidence presented here.

This is probable the most informative video I have watched in a very long time...

Start spreading the news...


Sent from my iPad using Tapatalk

Reactions: Like 2 | Agree 1


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## Rob Fisher (13/11/17)

Fantastic video! Real food for thought and certainly explains why I get such great flavour from the Skyline! Boom!

Reactions: Like 2


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## Seemo.wm (13/11/17)

So as much as he is disliked, riptrippers was correct in stating that coils ahould be directly in line with the airflow.

Painfully Long but interesting vid!

Reactions: Like 1 | Agree 1


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## Huffapuff (14/11/17)

Great video, thanks for sharing @Gonzilla

There is a lot of anecdotal "evidence" in vaping, so it's great to see someone trying to apply a more scientific method.

Now I have to go recoil and rewick all my RDAs to check this out!

Reactions: Agree 2


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## Puff the Magic Dragon (14/11/17)

Great video. Thanks @Gonzilla .

Wonderful to see such passion. Poor old Morten Oen throwing himself on his sword for misleading the public. I would have just said that almost everyone, including me, were wrong but I have now provided the proof that will help us all.

After we have all rebuilt our RDAs to his specs I trust that we will all subscribe to his channel and thank him (if it proves to be correct ).

I have proved to myself that padding open spaces with cotton to reduce chamber size is the way to go. Somewhere on the forum I mentioned that I did this with a single coil build in the goon 1.5. This has nothing to do with what Oen says about coil placement, but is in line with his belief in adding cotton padding.

Reactions: Like 2


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## Seemo.wm (14/11/17)

Puff the Magic Dragon said:


> padding open spaces with cotton to reduce chamber size is the way to go.



On the point of putting corron in open spaces, when I just started building, i used to put extra corton between the posts, thinking it would reduce leaking. I was too inexperienced to notice a change in turbulence, but what i did notice was that the cotton in the middle changed colour about 2 times faster than the cotton inside the actual coil.
Just something to point out and would be interesting to know why.

Reactions: Like 2


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## Rude Rudi (14/11/17)

I did the coil position change on the Pulse and the change is subtle but noticeable...

Now, to recoil my family of RDA's!!!

Reactions: Like 3


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## Silver (14/11/17)

Very interesting
Thanks for sharing @Gonzilla 

I like how he tried to investigate the airflow in his real life simulations

The atty I have tried the most variations of in terms of coil positions is the RM2. 
Not approaching it from his angle of understanding the airflow, but rather trial and observation.
When my coil is higher than the airhole (what he reocmmends NOT to do) i get better throat hit - because i think the vaporisation is happening closer to my mouth - thats my theory  but its definitely the better position for me.

I wonder whether the atty designers run airflow simulations on their own chambers to tweak it and then also can tell us where the best place is to put the coil...

The point of using cotton to block off unnecessary airspace in the atty is cool. I would like to try that.

PS - @Stosta - your beard is longer than his

Reactions: Funny 2


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## Rude Rudi (15/11/17)

I changed the position in a bunch of my RDA's last night based on this "new" method. I'm not sure it is because I am looking for an improvement but there is a noticeable difference in terms of flavour, cloud production & smoothness. 

Will give a couple of days but so far so good!

Reactions: Like 1


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## Silver (15/11/17)

Rude Rudi said:


> I changed the position in a bunch of my RDA's last night based on this "new" method. I'm not sure it is because I am looking for an improvement but there is a noticeable difference in terms of flavour, cloud production & smoothness.
> 
> Will give a couple of days but so far so good!



What did you do @Rude Rudi ? 

Move the coil directly in line with airflow instead of above or below?
Move the coil further away from the airhole?
Did you use cotton to remove unnecessary air space?


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## Rude Rudi (15/11/17)

Silver said:


> What did you do @Rude Rudi ?
> 
> Move the coil directly in line with airflow instead of above or below?
> Move the coil further away from the airhole?
> Did you use cotton to remove unnecessary air space?



Yes, basically all of the above.

I moved the coils directly in line with the airflow. On the Goon OG and Dead Rabbit, I lowered the position of the coil as it was way to high.
It was tricky on the Rabbit as the air hole slots are angular so I employed a paperclip which a stuck through the airhole to indicate the correct position.
The goon was much easier as you can see through the air holes so it was just a matter of lowering the coils about 2mm.

Really pleased with the results...

Reactions: Like 3


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## Faheem777 (15/11/17)

Rude Rudi said:


> Yes, basically all of the above.
> 
> I moved the coils directly in line with the airflow. On the Goon OG and Dead Rabbit, I lowered the position of the coil as it was way to high.
> It was tricky on the Rabbit as the air hole slots are angular so I employed a paperclip which a stuck through the airhole to indicate the correct position.
> ...



Any chance you can post some pics? Quite keen to test this theory out


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## Raindance (15/11/17)

Guys, allow me to be 'that' guy and demonstrate some sceptisism on what is being presented in terms of simulations. They are not an accurate reproduction of what happens to airflow over a hot coil that is emitting a considerable amount of expanding vapor from its surface. The same hot surface now being heated inconsistently due to the cooling effect of the direct airstream from one side...

I am not saying his results and findings are incorrect, I am however questioning the validity of the Methodology and simulations used.

Got that off my chest and feeling a lot better now. Regards

Reactions: Like 3


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## AlphaDog (15/11/17)

Super interesting video! I actually subscribed to his channel now too, I really enjoy this kind of science and evidence backed recommendations. @Gonzilla, thank you for sharing - i learned something great today


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## Rude Rudi (15/11/17)

Faheem777 said:


> Any chance you can post some pics? Quite keen to test this theory out



A bit tricky as I dont have a macro lens but here goes.

I adjusted the position of the coils here in the Goon OG. Previously, the coils were placed higher so that when you look through the air holes, you see the bottom of the coils. I lowered the coils slightly as suggested to now be in line with the air holes. 

Now, you see the coil straight on:



Side view:



See the toothpick as guide on the bottom coil = straight and hitting the coil in the middle of the middle:



I have not added extra padding here - will give it a go but there is not much room at the bottom of the Goon so I don't think it's necessary in this instance. 

So far, so good.

Reactions: Like 4 | Winner 1 | Thanks 1


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## AlphaDog (15/11/17)

I commented on Morton Oen's video with a link to this thread! He responded and is checking this out

Reactions: Like 2


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## Paul33 (16/11/17)

I tried it last night in my icon. 

Moved the coil down about 2-3 mm so it hits directly side on. 

I’m gonna give it a day or 2 to really test it but I would say the flavour is a bit better!!

Need to rebuild the goon and will try this out and see.


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