The last time I checked, there was nothing but air "just back of the
trailing edge of the wings". :-)
Garry Stout
Flying Trigear N4220S
Subject: RE: NACA vent placement (was RE: Europa-List: Gel Coat)
>
> On a Few of the RV's the owners are putting NACA vents just back of the
> trailing edge of the wings to help exhaust the cabin air and relieve
> cabin pressure. That may not be a place for positive air flow.
>
>
> David DeFord wrote:
>
> <davedeford@comcast.net>
> >
> >>Now for a question of my own. I'm considering where I should put the
> >>NACA vent that will feed the eyeball vents that I'm installing in the
> >>overhead panel. I have a fairly large vent with a 2" opening for the
> >>feed tubing. Would the intake be effective if installed somewhere in
> >>the vicinity of the battery, starboard side, behind the luggage tray,
> >>just above flap level, or maybe even below flap level? Would it be
> >>possible to locate it underneath the fuselage?
> >>
> >>Jeff - A055
> >>
> >>
> >
> >Jeff,
> >
> >I would avoid any location below the wings. We had a persistent
> problem
> >with carbon monoxide in N135TD, and one of the sources turned out to be
> >exhaust gas that entered the rear fuselage through the flap drive
> slots.
> >Even though the air leaking from the tail cone into the cockpit was
> diluted
> >by a much larger intake from our fresh air vents, we still saw about 30
> >parts per million of CO from this source. I suspect that the level
> would be
> >much higher, if your primary ventilation source were picking up air
> that
> >contained exhaust emissions. It might be okay if you kept the inlet on
> the
> >opposite side from the exhaust, but I would make careful measurements
> in any
> >case. Air pressure is likely to be lower on the aft fuselage surfaces,
> so a
> >more forward location may give better air flow as well.
> >
> >Dave DeFord
> >N135TD (flying, 320 hours)
> >
> >
> >
> >
>
> Dave,
>
> Thanks for the information. I considered the exhaust gas problem, but
> assumed that it would not be a problem on the lower starboard side of
> the fuselage, due to the prop wash lifting it upward. I also assumed
> that the lower fuselage, being fairly flat would give a good airflow
> through the vent. Anyone have any experience with vent inlets in these
> positions? Would it be possible for someone, with a running Europa, to
> make a few CO2 measurements in the areas I'm talking about? Any
> assistance would be greatly appreciated...
>
> Jeff - A055
> Builders Log: http://www.N55XS.com
>
>
> ==
> ==
> ==
> ==
>
>
|