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Cabin vent - air outlet?

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frans(at)paardnatuurlijk.
Guest

Posted: Mon Sep 08, 2008 11:24 pm Post subject: Cabin vent - air outlet?

It is easy to install air inlets, there are plenty of examples in the galleries and build logs.

But when air enters the cabin, air has also to be able to leave somewhere.

How have people accomplished this? I don't see any examples for this.



Originally, I planned to make an exit in the D-panel, and let the air escape via the rear fuselage (trim tab slots). But now I've read that the rear fuselage has a higher pressure than the cabin.



What is the best way to vent the cabin, to obtain a steady airflow, rather than trying to pressurize the cabin or to get oscillations in the air? Any ideas or satisfying implementations?



Frans

Visit -  www.EuropaOwners.org

craigb(at)onthenet.com.au
Guest

Posted: Tue Sep 09, 2008 1:42 am Post subject: Cabin vent - air outlet?

Lance who is building a Mono about three hours drive from myself has an

outlet installed in the top

of the "D" that vents to freestream airflow just behind the bulkhead via

ramp simmilar to a cowl flap

exit, it slopes in line with the fuselage so rain etc doesnt try and fill up

the "outlet" while parked

I plan to do the same on mine, from memory he has a small baffle plate that

can be adjusted as needed and closed

when parked.



craig



--

philipgeorge347(at)hotmai
Guest

Posted: Tue Sep 09, 2008 2:02 am Post subject: Cabin vent - air outlet?

Frans . You will find if it is a mono wheel  Cair will be drawn out thru the wheel- well as this is a low pressure area .Being drawn thru the retraction lever slot . This is not so on the tri-gear. 

  

 Phil George .XS Mono wheel.



 	  Quote: 	
		   Subject: Cabin vent - air outlet?

 From: frans(at)paardnatuurlijk.nl

 Date: Tue C 9 Sep 2008 10:23:40 +0300

 To: europa-list(at)matronics.com

 

 --> Europa-List message posted by: "Frans Veldman" <frans(at)paardnatuurlijk.nl>

 

 It is easy to install air inlets C there are plenty of examples in the galleries and build logs.

 But when air enters the cabin C air has also to be able to leave somewhere.

 How have people accomplished this? I don't see any examples for this.

 

 Originally C I planned to make an exit in the D-panel C and let the air escape via the rear fuselage (trim tab slots). But now I've read that the rear fuselage has a higher pressure than the cabin.

 

 What is the best way to vent the cabin C to obtain a steady airflow C rather than trying to pressurize the cabin or to get oscillations in the air? Any ideas or satisfying implementations?

 

 Frans

 

 

 

 

 

 

 Visit - www.EuropaOwners.org

 

&=======================
	


&g=

 	  Quote: 	
		   

 

 


	


Try Facebook in Wint/01/' target='_new'>Try it Now!  [quote][b]

wooburnaviation(at)google
Guest

Posted: Tue Sep 09, 2008 2:05 am Post subject: Cabin vent - air outlet?

Well we must have had a particulary draughty rear fuselage, as we had a domestic plastic vent grill in the D panel, and that seemed to work fine when combined with a NACA duct.  I think the NACA placement is more important, bearing in mind the low pressure that definately exists on top of the wing !

   

 Dave



 

 On 09/09/2008, Frans Veldman <frans(at)paardnatuurlijk.nl (frans(at)paardnatuurlijk.nl)> wrote: [quote]--> Europa-List message posted by: "Frans Veldman" <frans(at)paardnatuurlijk.nl (frans(at)paardnatuurlijk.nl)>

 

It is easy to install air inlets, there are plenty of examples in the galleries and build logs.

But when air enters the cabin, air has also to be able to leave somewhere.

How have people accomplished this? I don't see any examples for this.

 

Originally, I planned to make an exit in the D-panel, and let the air escape via the rear fuselage (trim tab slots). But now I've read that the rear fuselage has a higher pressure than the cabin.



What is the best way to vent the cabin, to obtain a steady airflow, rather than trying to pressurize the cabin or to get oscillations in the air? Any ideas or satisfying implementations?

 

[b]

josok-e(at)ukolo.fi
Guest

Posted: Tue Sep 09, 2008 2:55 am Post subject: Cabin vent - air outlet?

Don'f wotty about venting out, if there would be over-pressure in the cabin, it will lift/bulge the doors enough to escape. The rear of the fuselage definitively has a higher pressure, probably from high pressure air from under the wings entering the flap drive slots. There always was a cold draft though the flying controlsblowing into the cockpit. The UC slot did not have any effect. With flaps down, slow approach, there was an exhaust smell entering from somewhere.Never found out from where, opening the vents fully reduced it.



Regards,



Jos Okhuijsen

Visit -  www.EuropaOwners.org

raimo.toivio(at)rwm.fi
Guest

Posted: Tue Sep 09, 2008 3:45 am Post subject: Cabin vent - air outlet?

That´s true. Through the UC slot you can see mother ground

 but nothing comes in. 

  

 Somebody wrote years ago if you forget to close the door(s) properly

 (one shooting bolt is not in) you will notice it soon, 

 because in that case the UC slot will be an air inlet instead of  outlet.

  

 I have had no problems with air outlets.

  

 During cold seasons I feel some nasty draught (extra air inlets)  from

 the headrest and seat ass storage areas. They should be fully closed  but

 obvioushly they are not. They are on my list to improve. Any ideas?

  

 Raimo from Finland

 OH-XRT

  

  

  

 ---

kheindl(at)msn.com
Guest

Posted: Tue Sep 09, 2008 5:52 am Post subject: Cabin vent - air outlet?

Frans,



One neat solution is by Ian Rickard, with an opening in the D-panel and ducted to an outlet in the tailfin.



I never noticed any problem, with a little vent in the rear of the door , and as Josok says, air will also escape past the door seals.



Karl





----------------------------------------

 	  Quote: 	
		   Subject: Cabin vent - air outlet?

 From: frans(at)paardnatuurlijk.nl

 Date: Tue, 9 Sep 2008 10:23:40 +0300

 To: europa-list(at)matronics.com

 

 

 

 It is easy to install air inlets, there are plenty of examples in the galleries and build logs.

 But when air enters the cabin, air has also to be able to leave somewhere.

 How have people accomplished this? I don't see any examples for this.

 

 Originally, I planned to make an exit in the D-panel, and let the air escape via the rear fuselage (trim tab slots). But now I've read that the rear fuselage has a higher pressure than the cabin.

 

 What is the best way to vent the cabin, to obtain a steady airflow, rather than trying to pressurize the cabin or to get oscillations in the air? Any ideas or satisfying implementations?

 

 Frans

 

 

 

 

 

 

 Visit -  www.EuropaOwners.org

grahamsingleton(at)btinte
Guest

Posted: Tue Sep 09, 2008 6:35 am Post subject: Cabin vent - air outlet?

Frans

I used to notice the draft tugging gently at my sleeve! It is worth 

putting a nylon latch half way along the door frame to hold the latched 

door in place

Graham



Karl Heindl wrote:

 	  Quote: 	
		   

 Frans,



 One neat solution is by Ian Rickard, with an opening in the D-panel and ducted to an outlet in the tailfin.



 I never noticed any problem, with a little vent in the rear of the door , and as Josok says, air will also escape past the door seals.



 Karl

frans(at)paardnatuurlijk.
Guest

Posted: Tue Sep 09, 2008 1:56 pm Post subject: Cabin vent - air outlet?

Thanks for the answers. I'm building a tri-gear by the way. As air inputs I have a scoop in the top (in the closed position it is completely level with the fuselage), windows with a vent opening, and these ACS "ultimate vents" just below the instrument panel. I guess this is enough for air vents.



The general consensus seams to be that the doors will function as an air exit. I'm not to happy with that, for I try to keep them into their intended shape (have some aluminium bar rivited in to discourage them from bulging out) and using them as an exit will probably generate some noise. Good idea that the area above the wing will be low pressure, I could maybe make some gills in the bagage bay just above the wing. Anything that enters via the flap slots will find a quick way out then as well.



Frans

Visit -  www.EuropaOwners.org

hagargs(at)earthlink.net
Guest

Posted: Tue Sep 09, 2008 6:43 pm Post subject: Cabin vent - air outlet?

I had vents in the D panel and  the higher pressure in the  back caused

some exhaust getting into the flap slots while going slow to enter  the

cockpit.  After performing a preflight on a Liberty (certificated Europa?)

I noted 2 openings on the bottom of  the fuselage.  Each had a reverse

scoop over it.  I went back to my Europa. I already had an access door

under the  fuselage for the  gascolator.  I pulled the door off  approx 4"

X 5" and  fashioned a reverse scoop out of  fiberglass.  In addition to

this I made better closure of  the flap slots using rubber sheeting.  The

results were noticeably better, using a CO monitor.  I now only get a short

beep once in a while in the pattern rather than exceeding limits.



Steve Hagar

A143 

Mesa AZ

 	  Quote: 	
		   [Original Message]

 From: Frans Veldman <frans(at)paardnatuurlijk.nl>

 To: <europa-list(at)matronics.com>

 Date: 9/9/2008 12:27:37 AM

 Subject: Cabin vent - air outlet?



 

<frans(at)paardnatuurlijk.nl>
	


 	  Quote: 	
		  

 It is easy to install air inlets, there are plenty of examples in the

galleries and build logs.
	


 	  Quote: 	
		   But when air enters the cabin, air has also to be able to leave somewhere.

 How have people accomplished this? I don't see any examples for this.



 Originally, I planned to make an exit in the D-panel, and let the air

escape via the rear fuselage (trim tab slots). But now I've read that the
	


rear fuselage has a higher pressure than the cabin.

 	  Quote: 	
		  

 What is the best way to vent the cabin, to obtain a steady airflow,

rather than trying to pressurize the cabin or to get oscillations in the
	


air? Any ideas or satisfying implementations?

 	  Quote: 	
		  

 Frans

 Visit -  www.EuropaOwners.org

g-iani(at)ntlworld.com
Guest

Posted: Wed Sep 10, 2008 1:53 am Post subject: Cabin vent - air outlet?

Frans



Karl has made reference to my vent mod.  I have tidied up the documentation

a little and it is attached.  I do not suggest it is the right solution

rather an experiment.  So far I have not made the time to do any detailed

measurements.



I have never detected air moving in or out round my door seals.



Ian Rickard G-IANI XS Trigear, 200 hours

Europa Club Mods Rep (Trigear)

e-mail mods(at)europaclub.org.uk   

   or direct g-iani(at)ntlworld.com 



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Cabin_Air_Extractor.pdf

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sidsel.svein(at)oslo.onli
Guest

Posted: Wed Sep 10, 2008 7:40 am Post subject: Cabin vent - air outlet?

After consulting with EA2004 about any possible strength issues (none), I 

built an air outlet vent on top of the fuselage behind the doors - see 

attached photo.  This is a low pressure area.



Under the fore part of this vent is a 2 inch hole through the fuselage.  I 

built a sliding valve under the hole to partially or fully close the 

opening.  I have, however, during two years of flying never adjusted this 

valve from full open, whether in summer time or during the winter, so I 

consider it unnecessary to have it.  Air flow through the cockpit is instead 

controlled only by the fresh air or heater inlets (either ones always open 

to some extent).



Svein

LN-SKJ

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frans(at)paardnatuurlijk.
Guest

Posted: Wed Sep 10, 2008 1:08 pm Post subject: Cabin vent - air outlet?

[quote:9df425b733="g-iani"]Frans



Karl has made reference to my vent mod.  I have tidied up the documentation

a little and it is attached.  I do not suggest it is the right solution

rather an experiment.  So far I have not made the time to do any detailed

measurements.



-----[/quote:9df425b733]



I like this mod. Looks like a low drag solution and very effective, provided that the stern post is a low pressure area indeed. I'm going to try this, if it doesn't work very well I have not made any modification to the exterior of the airplane, so I can easily undo it. It doesn't take much to implement this.



Another mod could be to make this opening, but without the hose. This might reduce the pressure in the rear fuselage, keepiing the exhaust fumes away from the cockpit, and a vent in the D-panel will then also work better.



Frans

Visit -  www.EuropaOwners.org

steven.pitt2(at)ntlworld.
Guest

Posted: Wed Sep 10, 2008 10:32 pm Post subject: Cabin vent - air outlet?

I have fitted Ian's mod and it also appears to work as I do not have the 

tugging shirtsleeves from the doors. My only comment about positioning is 

that if you go below the 'd' in the bulkhead, if you travel any distance 

with luggage this blocks the outlet. The positioning is a compromise.

Steve Pitt

G-SMDH

---

g-iani(at)ntlworld.com
Guest

Posted: Thu Sep 11, 2008 12:44 am Post subject: Cabin vent - air outlet?

Frans



 	  Quote: 	
		  I like this mod. Looks like a low drag solution and very effective,

provided that the stern post is a low pressure area indeed. I'm going to try
	


this, if it doesn't work very well I have not made any modification to the

exterior of the airplane, so I can easily undo it. It doesn't take much to

implement this.<



Yes that was my thinking



 	  Quote: 	
		  Another mod could be to make this opening, but without the hose. This might

reduce the pressure in the rear fuselage, keepiing the exhaust fumes away
	


from the cockpit, and a vent in the D-panel will then also work better.<



Yes we have tried this and it does make a difference.  As I said we have not

had time to do detailed measurements.



Ian Rickard G-IANI XS Trigear, 200 hours

Europa Club Mods Rep (Trigear)

e-mail mods(at)europaclub.org.uk   

   or direct g-iani(at)ntlworld.com

karelvranken(at)hotmail.c
Guest

Posted: Thu Sep 11, 2008 11:12 am Post subject: Cabin vent - air outlet?

Svein,

You say the area where you placed the outlet is a low pressure area. Are you 

sure? Did you measure that pressure? I think when the profile is diminishing 

the pressure raises. On that place I have an intake for ventilation and even 

in hot days I can't open fully the inlet because the windstream can't be 

endured for a long time.

Regards,

Karel Vranken.  F-PKRL

---

frans(at)paardnatuurlijk.
Guest

Posted: Thu Sep 11, 2008 12:25 pm Post subject: Cabin vent - air outlet?

[quote:67f80f7028="stevenwpitt"]



I have fitted Ian's mod and it also appears to work as I do not have the 

tugging shirtsleeves from the doors. My only comment about positioning is 

that if you go below the 'd' in the bulkhead, if you travel any distance 

with luggage this blocks the outlet. The positioning is a compromise.

Steve Pitt

G-SMDH

-----[/quote:67f80f7028]



I was thinking about putting it in the top of the bulkhead. As I have a hi-top, there is excess space above this 'D'.



Frans

Visit -  www.EuropaOwners.org

sidsel.svein(at)oslo.onli
Guest

Posted: Thu Sep 11, 2008 1:33 pm Post subject: Cabin vent - air outlet?

Karel,



No, I have not measured the pressure, I relied on what EA2004 said also 

about the pressure in this area.  I think they were correct, because the air 

speed over the top is higher than the airplane's speed through the ambient 

air and hence the pressure is lower than the ambient pressure (compare the 

fuselage profile to a wing profile - higher speed hence lower pressure on 

top of the wing).



All I can say for sure is that the pressure at my vent outlet is lower than 

in the cockpit, because air goes out through that vent (I can feel the air 

flow by holding my hand under the outlet opening).  The air pressure in the 

cockpit may be higher than ambient, though, because of the efficient NACA 

intakes on both sides (built as per Europa standard).  If air comes in 

through your vent, it must mean that your cocpit pressure is lower than at 

your top vent opening.  Where does this air leave your cockpit?



Svein

---

karelvranken(at)hotmail.c
Guest

Posted: Fri Sep 12, 2008 11:41 am Post subject: Cabin vent - air outlet?

Svein,

Air leaves the cockpit area trough the undercarriage lever arm sleeve and 

perhaps other holes. I can put a botlang leaf on this place and it will not 

move.

Karel Vranken  #447 F-PKRL

---

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