Peter Anson Fresh Air Ducts

[WilliamBatten]

I'm ready to install my Peter Anson fresh air ducts into the side of the fuselage. I know I need them within reach during flight. Apart from that, there is still a lot of real estate available - just looking for someone who has already gone down this path and are happy with the results.

So, the question is: Where is the best place to install these NACA vents? Do they need to be parallel with the line of flight? Or, can they be tilted up a bit to aim more towards the pilots head?

Peter - fell free to chime in if you know the best location in a "B" model.

[Tnhelm]

I installed one of Peter’s NACA air ducts on my OneX. The unit I selected can be opened and closed, creating a flush exterior when closed. I located it forward of the wing to avoid the low pressure area over the wing. The location is next to my left ankle. I can operate it by rolling the jack screw wheel up and down with my foot. I have no ducting and the air flow is very strong, flooding my whole body from the legs up. There is even good airflow on the ground from the propeller. I keep the canopy latched.
I had considered installing one on each side if needed but found the one is more than adequate. For a two place A or B model, a second one would probably be appropriate.
The only downside of my application was attempting to adjust it while taxiing (and momentarily loosing directional control). I tried a couple of times, wasn’t pretty.

Tnhelm
OneX 0137

[T41pilot]

Bill

I mounted mine on the fuselage just under the top rivet line so that the airflow would be just under the bottom of the instrument panel. I have wiring in the area so the fore/aft position was determined to fit between that stuff. I can reach it when seated but I have to lean forward to do so. Can't reach when belted in so I usually set the airflow I think I need for the flight before I leave on both sides. I think they have to be in line with the airflow for them to function correctly. Tipping would reduce their efficiency if not kill most of the airflow altogether and may create drag. I think the whole idea of a naca vent was to provide air with little or no drag as compared to a scoop.

So far, my vents work as advertised and provide enough air to be comfortable. I haven't tested the comfort level on a real hot day though. I still may have to get a canopy sun shield if I do any flying other than going to breakfast. I do like the fact that the fuselage opening can be closed off when not in use. May help to keep moisture or rain out.

I tried to attach a picture but this site just logs me off when trying to upload it. The picture was properly formatted for size so I don't know what the deal is. Message me with your e-mail if you need to see it.

[Bryan Cotton]

Here are pictures showing the inside and outside view of my Peter Anson ducts:




If you are on a phone you may need to open the picture to see the whole thing. My ducts are an earlier version, and they really were not providing the hurricane I was hoping for. Could be poor placement as well. What I made to help is a little scoop that slides onto the aft part of the NACA duct and sticks out a little. That made a huge difference and I use them in hot weather. I'll get pictures next time I'm at the hangar. I do like the location as I can operate either vent when flying solo. With the scoops the airflow is excellent.

[daleandee]

I can't speak for Peter's vents but I used NACA ducts with eyeball vents in the panel. I was taught (at least for the A model) to place the NACA ducts as far forward and as high as possible. I did that. I get good airflow on the ground and great airflow in flight.

[Bryan Cotton]

Here are my scoops:

Screenshot_20240123-174820-567.png (613.16 KiB) Viewed 785 times

Two pieces of .016 bent at the same angle, and riveted together. There is a small gap after the bend that lets me slip it into the fuselage skin at the back of the NACA cutout. I use silver 200mph tape (174 kt) to keep them attached.

[sonex892.]

Not sure about the B model but with my A model I found that the original plans vent placement wasnt the actual issue. The problem was the sonex catflap vent. Almost zero air entered with the vent opened.

Using the same location I changed to a naca vent profile from a Bingelis book. It is now like a hurricane with the vents opened in flight.

An old thread here shows how I did it.

viewtopic.php?f=3&t=275&p=1987&hilit=polished+duct#p1987

[WilliamBatten]

What fantastic support - thanks to everyone.

[Bryan Cotton]

One thing nobody mentioned was that NACA ducts should be parallel to the airflow. We assume the airflow is straight where we mount them. Plus it looks right.

Steve those aluminum ducts are awesome, nice workmanship.

[Onex107]

Those of you that need cockpit air vents, look into the RV alum vents that close flush to the fuselage. They are adjustable and you can't beat the price.