From: "Will Chorley" Subject: COZY: Air vents and Oil Cooling Date: Mon, 15 Feb 1999 20:11:45 -0600 Now my plane is back on it's feet, I am about to put the finishing touches to the fuselage before finishing the top side. One item still to be done is the provision of personal air vents up front. I plan to use the lower cost plastic type eyeball vents from ACS with a direct flow from a couple of NACA scoops under the canard (This seems to be the "standard" arrangement for personal cooling). These vents would appear to have a cross section of about 3 sq. in. but I guess if I made the NACA scoops and ducts this size I would be blasted with air at around 200mph! Something smaller would allow the air to slow down a bit before being discharged in my face. So, what's a good size for the scoop that will give plenty of cooling on a hot Texas day? Perhaps those who are flying have some experience that they would pass along. Another NACA scoop question relates to oil cooling (this may be a question for Vance Atkinson). Using Vance's scheme for oil cooling, (air scooped up through the fairing, directly through the oil cooler and out of the top of the cowling) what size NACA scoop should I carve in the fairing to keep things cool? Any other oil cooling tips/alternatives that need some accommodation before final finishing? Looking forward as always to your helpful advice, Will From: cdenk@ix.netcom.com Date: Mon, 15 Feb 1999 21:27:42 -0600 (CST) Subject: Re: COZY: Air vents and Oil Cooling Naca fresh air inlets: I have 2 on the underside of the nose, about in line with the nose gear pivot bolt. Note my Cosy nose is more blunt than usual Cozy. Their width is 2.3" and about .75" high opening. The location and size gives more than enough air flow and rain is not an issue. Inside there are a 3/4" aeroduct to my nose mounted landing lights where the air the exits into the nose gear box. Also there are 2" aeroducts to fiberglass distribution boxes just aft of F-22. Passing F-22, the duct is fiberglass part of the boxes that is flattened round to give more room for your toes. Out of the boxes are 3 - 3/4" aeroduct to cool the 2 Kx-155 navcoms and the IIMorrow GPS, plus 2 1.5" or was it 1.75" aeroduct to Wemac aluminum eyeball vents. The vents are located top of the instrument panel above the top stiffening rib, outboard (just inboard of the canopy rail). The location works well, being able to blow in your face, or elsewhere. Check the size of the plastic vents, they may be considerably larger, and space is premium. There also should be cabin air exit vents. I have 2.5" screened openings in the rear headrest, and then reverse gill vents above the strakes and forward of the firewall. Date: Mon, 15 Feb 1999 22:33:13 -0500 From: Bulent Aliev Subject: COZY: Air scoops Few days ago someone was looking for prefabricated air scoops. Check this web page: http://www.a-aspec.com/scoopindex.html Bulent From: "Tom Jacobs" Subject: COZY: cabin cooling air Date: Tue, 13 Apr 1999 22:07:57 -0500 Has anyone tried to get cooling air for the cabin from the nose gear wheel well? I know that most people put NACA scoops just forward of the instrument panel. I would rather not put any more holes in the fuselage, especially where water may get in. The wheel well seems like a natural place to get the air from. The airflow is already disturbed, it is out of the rain, and is hidden from view. Is the air pressure in the wheel well high enough to force air into the plane? If not, is there some simple way to raise the pressure? I would appreciate hearing about any thoughts on the subject. - --- -- Tom Jacobs tjacobs@madison.tds.net From: Todd Carrico Subject: RE: COZY: cabin cooling air Date: Wed, 14 Apr 1999 07:30:40 -0700 Have you ever smelled a tire? Have you thought about a naca scoop under the strake? It would be high pressure (only when the craft was airborne), and hidden from most viewers (3 feet and taller), and should be dry most of the time. I guess you could also put them on the bottom of fuse. I would stay away from the wheel well just because of the smell. The naca duct works by creating vorcicies and then capturing them. Any preassure differential should be enough to get air in. Differential is the key. High pressure air will always seek out low pressure. You would need to make sure that you have adequate exits for your incoming air. From what I hear that makes a big difference. Someone metioned the wing attach bolt covers as a good source for an exit. Don't know if they were serious, but it sounds plausable. Let us know what you end up with. tc -----Original Message----- From: Rego Burger To: cozy_builders@canard.com Sent: 4/13/99 10:47 PM Subject: COZY: cabin cooling air >>>>Has anyone tried to get cooling air for the cabin from the nose gear wheel well?<<<< Thought about it but I came to the conclusion that airflow would only be positive in a climb... one wants air 90% of the time in straight and level... so the nose gear well once gear is up would most likely have very little positive pressure, remember the wheel will take up most of the space and the rest of the air will be deflected away. This is all theory so I have not done any tests to proove or disproove my theory. Rego Burger RSA Date: Wed, 14 Apr 1999 21:01:54 -0500 From: David Domeier Subject: Re: COZY: cabin cooling air Rego, re "..so the nose gear well once gear is up would most likely have very little positive pressure, remember the wheel will take up most of the space and the rest of the air will be deflected away. This is all theory so I have not done any tests to proove or disproove my theory." I think you are correct, without testing it. I had a small scoop on the canopy of my LEZ just forward of the glass and it had zero airflow until the airplane got up to 110 knots. The 2 air intakes on either side the MKIV provide air all the time....in fact it is necessary to close down the inflow on most flights. dd Date: Sun, 18 Apr 1999 13:40:14 -0400 From: Carl Denk Subject: Re: COZY: cabin cooling air Tom Jacobs wrote: > Has anyone tried to get cooling air for the cabin from the nose > gear wheel well? I have two NACA scoops in the nose bottom forward next to the gear well. The work excellent, and don't ever take in rain (Was in heavy rain yesterday near Gainseville, Ga.) Check archives for my posting on heating systems. Date: Sun, 18 Apr 1999 13:41:33 -0400 From: Carl Denk Subject: Re: COZY: cabin cooling air Rego Burger wrote: > positive in a climb... Mine are sufficiently forward to work all the time. From: Wayne Hicks Subject: COZY: Air vents in the rain Date: Mon, 7 Jun 1999 15:59:35 -0400 Hey group! Is there a way to build the cabin air vents to prevent water ingress? (besides closing the vents or avoiding flying through rain and clouds... screen, filter, diverter box, etc?) ____________________________________________________ L. Wayne Hicks Space Operations Division Sr. Engineer Zel Technologies, LLC 757-865-0900 phone 3221 North Armistead Ave 757-865-8960 fax Hampton, VA 23666 http://www.zeltech.com From: "Brown, Michael" Subject: RE: COZY: Air vents in the rain Date: Mon, 7 Jun 1999 13:33:00 -0700 My inlet scoop is located on the bottom of the nose, near the nose puck. I fly through clouds and rain on occasion and have yet to have any problems with rain in the plane. Mike Brown N97PZ Manhattan Beach, CA ---------- >From: Wayne Hicks Is there a way to build the cabin air vents to prevent water ingress? (besides closing the vents or avoiding flying through rain and clouds... screen, filter, diverter box, etc?)> From: "Wilhelmson, Jack" Subject: RE: COZY: Air vents in the rain Date: Mon, 7 Jun 1999 17:12:01 -0400 Mine are the same and "no rain in the plane". Jack Wilhelmson N711cz > -----Original Message----- > From: Brown, Michael [SMTP:Michael.Brown@AlliedSignal.com] > Sent: Monday, June 07, 1999 4:33 PM > To: 'cozy builders'; Wayne Hicks > Subject: RE: COZY: Air vents in the rain > > My inlet scoop is located on the bottom of the nose, near the nose puck. > I fly through clouds and rain on occasion and have yet to have any > problems with rain in the plane. > > Mike Brown > N97PZ > Manhattan Beach, CA > ---------- > >From: Wayne Hicks > Is there a way to build the cabin air vents to prevent water ingress? > (besides closing the vents or avoiding flying through rain and clouds... > screen, filter, diverter box, etc?)> From: cdenk@ix.netcom.com Date: Mon, 7 Jun 1999 16:48:29 -0500 (CDT) Subject: RE: COZY: Air vents in the rain Was said: My inlet scoop is located on the bottom of the nose, near the nose puck. > I fly through clouds and rain on occasion and have yet to have any > problems with rain in the plane. Mine are also in the nose bottom, and never had water problems, even in heavy rain in IFR conditions. Remember to put an metal insect screen near the entrance to prevent entrance by small rodents, insects, and reptiles. Date: Mon, 07 Jun 1999 18:00:14 -0400 From: "Marc J. Zeitlin" Subject: Fwd: RE: COZY: Air vents in the rain Jack Wilhelmson; >Mine are the same and "no rain in the plane". OK, so for those of us without the foresight to ignore the plans and put the airscoop on the bottom of the fuselage (and who followed the plans to a "T" here :-) ), how do _WE_ keep the rain out of the air vents? There are a zillion (well, maybe not quite that many) COZY's flying with the stock vents - what happens in the rain? Do we just get wet, or do we not need air vents when it's raining? -- Marc J. Zeitlin mailto:marcz@ultranet.com http://www.ultranet.com/~marcz/ From: cdenk@ix.netcom.com Date: Mon, 7 Jun 1999 17:20:04 -0500 (CDT) Subject: Re: Fwd: RE: COZY: Air vents in the rain Do we just get wet, or do we not need air vents when it's raining? I don't touch the airvents when going in and out of rain, always like to have at least a little fresh air coming toward the face. When its cold, the vents may be closed, but then its icing I'm concerned with. I have 3/4" flex tubing to 3 of the radios from the nose bottom vents, and thats much more critical than getting a few drops on my eyeglasses which has never happened. From: Wayne_Blackler@ansett.com.au Date: Tue, 8 Jun 1999 09:00:26 +1000 Subject: COZY: Air vents in the rain G'Day All, I was looking at cutting two small slits in the leading edge of the strakes (slightly under L.E. tangent point - high pressure), making a small plenum inside the strake and mounting eyeball vents on them. I have the Featherlite prefab strakes that have the D section hollow, and at this point I am not really happy taking up strake space. I'll bet there is a better, more obvious place for a nice vent intake, it just hasn't come to me yet... I think that intakes mounted on the fuselage bottom are a good idea as if any water is ingested into the intake it will drain after parking. I will use the wing attach access holes under the strakes for exits... Kind Regards Wayne Blackler O-360 Long EZ AUSTRALIA _____________________________________________________________________ CAUTION - This message may contain privileged and confidential information intended only for the use of the addressee named above. If you are not the intended recipient of this message you are hereby notified that any use, dissemination, distribution or reproduction of this message is prohibited. If you have received this message in error please notify Ansett Australia immediately. Any views expressed in this message are those of the individual sender and may not necessarily reflect the views of Ansett Australia. _____________________________________________________________________ From: "Nat Puffer" Subject: Re: RE: COZY: Air vents in the rain Date: Mon, 7 Jun 1999 19:39:37 -0500 Builders, The Cozy 3-place plans show the cabin air scoop to be underneath the nose. I put it there because I was using outside air not only for ventilation, but to defog and to cool the avionics. I put a lot of avionics in my 3-place that I never used, so when I built the 4-place, I installed fewer avionics and didn't need special cooling. I also learned that I didn't need defogging. So It was simpler to put the ventilation scoops in the fuselage sides and eliminate a lot of aeroquip ducting. With the scoops in the sides, the installation is a lot simpler, and when I fly through rain, even hard rain, I don't get enough drops through the NACA scoops to even talk about. Worry about it if you want, but I think it is a no-brainer! It never ceases to amaze me how many things first time builders can think of to worry about! Nat ---------- > From: Marc J. Zeitlin > To: Cozy Builders Mailing List > Subject: Fwd: RE: COZY: Air vents in the rain > Date: Monday, June 07, 1999 5:00 PM > > Jack Wilhelmson; > > >Mine are the same and "no rain in the plane". > > OK, so for those of us without the foresight to ignore the plans and put > the airscoop on the bottom of the fuselage (and who followed the plans to a > "T" here :-) ), how do _WE_ keep the rain out of the air vents? There are > a zillion (well, maybe not quite that many) COZY's flying with the stock > vents - what happens in the rain? Do we just get wet, or do we not need > air vents when it's raining? > > -- > Marc J. Zeitlin mailto:marcz@ultranet.com > http://www.ultranet.com/~marcz/ From: "Nat Puffer" Subject: Re: Fwd: RE: COZY: Air vents in the rain Date: Mon, 7 Jun 1999 19:51:14 -0500 Builders, In the Mark IV prototype we found some 90 degree eyeball vents and put them in the canopy frame, just aft of the instrument panel. We thought this was the neatest location, but the problem was that the 90 degree vents are too hard to find (ours were used), so the side vents were the next best choice for the plans model. We flew the Mark IV prototype for 4 years and I can't remember any problem in rain. You have to remember that water drops can't change direction as easily as the air, so most of them blow right past the scoop. Ken Murphy has been flying the prototype since 92, and he hasn't complained either. If he reads a copy of this, he might want to comment. The Velocity has the air scoops in the nose. Has anyone heard them complain? We have tried every location except the nose, and prefer the location that is easiest to install and takes up the least room. Nat ---------- > From: Bulent Aliev > To: > Cc: Cozy Builders Mailing List > Subject: Re: Fwd: RE: COZY: Air vents in the rain > Date: Monday, June 07, 1999 5:46 PM > > > > "Marc J. Zeitlin" wrote: > > > Jack Wilhelmson; > > > > >Mine are the same and "no rain in the plane". > > > > OK, so for those of us without the foresight to ignore the plans and put > > the airscoop on the bottom of the fuselage (and who followed the plans to a > > "T" here :-) ), how do _WE_ keep the rain out of the air vents? There are > > a zillion (well, maybe not quite that many) COZY's flying with the stock > > vents - what happens in the rain? Do we just get wet, or do we not need > > air vents when it's raining? > > > > -- > > Marc J. Zeitlin mailto:marcz@ultranet.com > > http://www.ultranet.com/~marcz/ > > I don't understand how all this people dare to call their planes Cozy? Any > deviation from the plans negate the name? We that have followed the plans for > the fresh air wents, have to put up with spray in the face and wet feet. I am > ready to fill my wents and take a leap away fro the plans. > On the other hand I can build an air box with drain tube on the bottom? > Bulent > From: cdenk@ix.netcom.com Date: Mon, 7 Jun 1999 21:07:14 -0500 (CDT) Subject: Re: COZY: Air vents in the rain Was said vents in strakes I am assuming the vent outlets would be mounted at the strake level, or at least below the upper longerons, and aft of the instrument panel, probably near the sticks. I find it highly desirable to be able to direct the air at my face during high temperatures, or if there is a contaminant say smoke or fumes from other sources. Also aiming at chest level is desirable when the air blasting at the face isn't wanted, but fresh air is wanted near the top of the body. I don't know of one auto or truck that has as the only vents, in the door is something to think about. My wemac eyeball vents are located high on the instrument panel above the top stiffener channel, as far outboard as the forward face duct connection would allow. They do not blow around charts or clipboard pages on my lap or hand. THe leading edges of the wings can get quite dirty with bugs. The other evening, a flight of less than an hour near Lake Erie resulted in the leading edges of everything nearly black with Canadian Soldiers (thats the name of the bugs). The air vent NACA's were clean. Cessnas use the leading edge air vents, they are noisy and leak water. Date: Mon, 07 Jun 1999 23:27:57 -0500 From: David Domeier Subject: Re: Fwd: RE: COZY: Air vents in the rain Marc, re "There are a zillion (well, maybe not quite that many) COZY's flying with the stock vents - what happens in the rain? Do we just get wet, or do we not need air vents when it's raining?" For all purposes practical, rain in-flight is horizontal. Ever notice the rain streaks on a side window of an airliner? You could measure the aircraft's angle of attack, they are so straight. I think it matters not where the air intake is located, the affect will be about the same. If the intake on the bottom of the nose does not enter rain, it sure won't on the side or top either. I've flown the MKIV in the rain and did not get wet through the side vent. dd From: "Schuler, Larry" Subject: RE: COZY: Air vents in the rain Date: Tue, 8 Jun 1999 08:21:00 -0500 Nat wrote: >It never ceases to amaze me how many things first time builders can think >of to worry about! Well from the look of your response concerning your personal concerns early on (and what you discovered works or doesn't work 'for you'), seems we worry, on average, about as much as you did. The single best thing about this list is the kind sharing of those who have learned things ahead of some of us so that we can make more educated decissions concerning our own experiment. Thanks for sharing what you worried about and learned ahead of us Nat and all. Larry From: cdenk@ix.netcom.com Date: Tue, 8 Jun 1999 15:27:27 -0500 (CDT) Subject: Re: Fwd: RE: COZY: Air vents in the rain Was said: If the intake on the bottom of the nose does not enter rain, >it sure won't on the side or top either. Moving air will tend to move some water with it if its not too far uphill. At some point the friction of the moving air does not overcome gravity, and it will be dry above that point. With the NACA's low, and a watertight duct for some distance up, there is considerably less chance of water entering the cabin area than with near and short horizontal ducts. From: cdenk@ix.netcom.com Date: Tue, 8 Jun 1999 15:33:16 -0500 (CDT) Subject: Re: RE: COZY: Air vents in the rain Nat said: I also learned that I didn't need defogging. Come up North and enjoy the changing seasons, here in Northern Ohio the defrosters are used frequently in the winter and cool rains. We fly year round and would rather fly during a clear zero F. day with nice clear visiblity that 95F, thermals from the farm land and 3 miles in haze. Date: Tue, 08 Jun 1999 17:44:32 -0500 From: David Domeier Subject: Re: Fwd: RE: COZY: Air vents in the rain Carl, re "With the NACA's low, and a watertight duct for some distance up, there is considerably less chance of water entering the cabin area than with near and short horizontal ducts." Probably true. It is also true that I flew through a small shower this afternoon with the left side vent full open and there was no water in the air coming in. I think the issue of "air vents in the rain" is not an issue. dd