Fresh air vents

MarkAR · #1 01-03-2012, 07:07 PM

Has anyone tried installing fresh air vents into the round inspection plates adjacent to the rudder pedals? It seems like a good way to get air down by your feet without cutting into the fuselage skin. You could even remove them in the winter and repalce with the original solid plates if you had air leakage. There is probably a way to make them operable in flight with a cable. Any other ideas on getting more fresh air into an RV-3?

Ironflight · #2 01-03-2012, 07:30 PM

Hmmm....I'm not actually sure what inspection plates you're referring to Mark. We just finished our -3B, and I don't recall seeing anything in the plans for them - but that doesn't mean anything, since every RV-3 is different and bears the unique ideas of it's creator!

We installed two round vents in our canopy skirt, but I am already thinking that when the weather warms up, we might have to add something like the RV-10 back-seat vents in the fuselage sides just below the longerons. The little round vents seem to be stuck in the boundary layer, and are not flowing a lot of air - I could maybe fix that with vortex generators or something, but we'll see....Several have taken fresh air into through the engine baffle and routed it to a vent in the cockpit.

I'm also curious to see other people's solutions!

Paul

Larry DeCamp · #3 01-03-2012, 08:27 PM

I have been thinking about small holes in the front of the cowling so you don't compromise engine cooling or get involved with the boundary layer complexities Paul referenced. The concept is something as small as 3/8" dia hole at 175 MPH would provide several cockpit air changes per minute. You can do the math with your own criteria. Small holes in the front of the cowling, what am I missing ??

Ironflight · #4 01-03-2012, 08:31 PM

Quote:

Originally Posted by Larry DeCamp

Small holes in the front of the cowling, what am I missing ??

Very interesting idea Larry. The only ptoential problem I see is having to connect and disconnect a hose every time you put the cowling on or off....sounds trivial, but I sure got tired of disconnecting a cowl-mounted landing light on my Grumman years ago....

David Paule · #5 01-03-2012, 10:07 PM

I think I read that the original had a slot in the front of the windshield to let air in, and a wedge that could be placed in it to block it.

Dave

dustman · #6 01-04-2012, 05:37 AM

David, you are correct I have one of the older planes and it does have the wedge in the lower portion of the windscreen. I can't tell you how well it works, as i have only flown it once, which was the first time and i was not paying to much attention to how well the air was moving in the cockpit.

rph142 · #7 01-04-2012, 06:06 AM

I installed two RV-10 vents. One is installed on the right side of the cockpit area about 6" below the canopy hinge and the other is installed on the left side down where your knees would be. The blow tons of air on the ground and if installed properly are almost invisible from the outside.

MarkAR · #8 01-04-2012, 11:06 AM

My 3 was built in the 80s and the builder installed round access plates like the ones under the wing in order to access the rudder petals and brake cylinders. It seemed like a good place to bring air in.

larryj · #9 01-04-2012, 01:00 PM

Interesting thread - RV-3 or otherwise. I have seen a couple of instances where cockpit fresh air was taken in from the forward edge of the wing-root fairing. Looked neat and word was that it worked well.
I am finalizing the build of my Rocket with minimal ventilation with the idea that I can add more later as needed; hence my interest in this thread.

Ironflight · #10 01-04-2012, 03:40 PM

Quote:

Originally Posted by larryj

Interesting thread - RV-3 or otherwise. I have seen a couple of instances where cockpit fresh air was taken in from the forward edge of the wing-root fairing. Looked neat and word was that it worked well.
I am finalizing the build of my Rocket with minimal ventilation with the idea that I can add more later as needed; hence my interest in this thread.

Our neighbor's F-1 is done that way, and he loves it. I looked into it for the -3, but the fuselage-to-wing gap is so small that it would have been really hard to install (not to mention that the forward tank attach point is in the way).

We also looked into putting a NACA scoop in the fuselage, under the cheek cowl - I've seen -4's do that. But there was no place to fit such a scoop on the -3 without intruding on leg or rudder pedal space.

Paul