X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 12 Nov 2012 08:21:58 -0500 Message-ID: X-Original-Return-Path: Received: from imr-ma05.mx.aol.com ([64.12.100.31] verified) by logan.com (CommuniGate Pro SMTP 6.0c2) with ESMTP id 5873985 for lml@lancaironline.net; Sun, 11 Nov 2012 20:49:30 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.100.31; envelope-from=vtailjeff@aol.com Received: from mtaout-mb04.r1000.mx.aol.com (mtaout-mb04.r1000.mx.aol.com [172.29.41.68]) by imr-ma05.mx.aol.com (8.14.1/8.14.1) with ESMTP id qAC1miww024155 for ; Sun, 11 Nov 2012 20:48:44 -0500 Received: from [192.168.1.119] (24-107-65-42.dhcp.stls.mo.charter.com [24.107.65.42]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mtaout-mb04.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPSA id 17A3FE0000C0; Sun, 11 Nov 2012 20:48:43 -0500 (EST) References: In-Reply-To: Mime-Version: 1.0 (1.0) Content-Type: multipart/alternative; boundary=Apple-Mail-5F670ABA-433D-4AE3-AF39-F5E6271FCFA9 X-Original-Message-Id: <6F5A0401-7E35-43EC-8093-40A84841CFCA@aol.com> Content-Transfer-Encoding: 7bit X-Mailer: iPad Mail (9B206) From: vtailjeff@aol.com Subject: Re: [LML] Re: Dukes pressurization controller X-Original-Date: Sun, 11 Nov 2012 19:48:39 -0600 X-Original-To: Lancair Mailing List x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:495570880:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d294450a0557b7a96 X-AOL-IP: 24.107.65.42 --Apple-Mail-5F670ABA-433D-4AE3-AF39-F5E6271FCFA9 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 It is normal to fly with ac on. Jeff Sent from my iPad On Nov 11, 2012, at 11:10 AM, wrote: > Dear subscribers, > =20 > Since we are talking about cabin heat I got another question. What cabin t= emperature do you get from your turbos on the cool side (after the intercool= ers and the additional heat exchanger in the front)? > =20 > I put my cool air supply hose in an additional fireproof jacket that has a= dditional insulation inside (see picture) =E2=80=93 the intension was to ins= ulate against engine heat and get nice cool cabin air. > =20 > At higher power settings (32 MAP, TIT1620) the cool cabin air is about 100= F. This means flying in the sun even in the high teens with OAT around 20F i= t still gets really warm in the cabin and I turn on the AC every now and the= n. > =20 > Is this normal? Any input is appreciated. > =20 > Ralf > =20 > From: Jack Morgan [mailto:jmorgan1023@comcast.net]=20 > Sent: Friday, November 09, 2012 8:45 AM > To: lml@lancaironline.net > Subject: Dukes pressurization controller > =20 > Just a quick note on the controller. Bob's excellent description below is a= ll good. The Dukes controller is an "aneroid" controller which needs no elec= tric power to operate once the airport elevation is set. > The electrical control for altitude setting in the cabin controls an elect= ric motor in the controller which sets the aneroid so that it controls cabin= pressure to just above the set airport altitude. This insures no pressuriza= tion is present at landing. Once set, an electrical failure will not cause a= ny problem for the cabin pressurization system. > =20 > Jack Morgan > =20 > On Nov 9, 2012, at 6:01 AM, Lancair Mailing List wrote: >=20 >=20 > From: Robert R Pastusek > Subject: RE: [LML] IVP cabin heat > Date: November 8, 2012 3:16:51 PM EST > To: lml@lancaironline.net > =20 >=20 > Dico, > =20 > I=E2=80=99ll answer via the LML as this may be of interest to other Lancai= r owners/operators. > =20 > First the disclaimer: The description below covers Lancair IV-Ps built usi= ng the parts provided by Lancair, and following the building manual. I have s= een a couple of other configurations out there=E2=80=A6the product of =E2=80= =9Cindividualism,=E2=80=9D and occasionally better ideas=E2=80=A6 So check t= o be sure your system is plumbed as described below before trying these thin= gs. > =20 > The IV-P uses bleed air from the engine turbochargers to both pressurize a= nd heat the cockpit. The compressed air pipe exiting each turbocharger has a= port added to tap off some of the air for the cabin. (By the way, this air h= as run through the turbochargers, but does not yet have any fuel added, so i= s breathable.) This port should have a =E2=80=9Csonic nozzle=E2=80=9D either= welded to the port itself, or installed in the SCAT/SCEET line that=E2=80=99= s attached. The sonic nozzle provides a relative constant flow of air to the= cabin heating/pressurization system over the typical range of pressure in t= he turbocharger system (typically 25=E2=80=9D-38=E2=80=9D MP at cruise power= settings). Depending on the power setting (MP), this compressed air is near= ambient temperature to quite hot (200+ degrees), and is the =E2=80=9Chot=E2= =80=9D feed for the cabin heating/pressurization system. It is routed via SC= AT/SCEET ducting to a flow controller (a gold-anodized round canister a bit s= maller than a coffee can) mounted to the top engine-side of the firewall. > =20 > The cabin heating/pressurization system has a second =E2=80=9Ccool=E2=80=9D= feed that starts with an additional port welded to the engine inlet air duc= ting downstream of the large intercoolers on each side of the engine. These p= orts are connected with SCAT tubing to a third intercooler on the forward le= ft chin of the engine, opposite the alternator. For the =E2=80=9Ccool=E2=80=9D= feed, compressed air passes through the side intercoolers, then through thi= s third intercooler and then via a single SCAT tube to the flow controller. N= ote that both hot and cool feeds are =E2=80=9Crelative.=E2=80=9D The hot sid= e can yield luke-warm air if the engine power is low, and the cool side is, a= t best, a few degrees above ambient; usually not cool at all in Florida in t= he summertime. > =20 > The above compressed air is fed into the cabin directly from the flow cont= roller on the firewall. With the cabin temperature control in the cold posit= ion, flow from the hot side (above) is completely blocked and all pressuriza= tion air is being fed into the cockpit from the cool side. With the temperat= ure control in the hot position, the cool side feed is blocked and the hot s= ide feed is fully opened. As a side note, the flow controller has a second f= unction that=E2=80=99s important. The =E2=80=9Cpressurization control=E2=80=9D= in the cockpit is connected to a flapper valve in the flow controller that a= lternatively opens a port allowing pressurized air to flow into the cockpit (= normal operation) and closes a =E2=80=9Cdump port=E2=80=9D that feeds air, v= ia a SCAT tube, down the forward side of the firewall to the engine exhaust a= rea. When in the dump position, this valve opens the dump port and closes th= e port into the cabin, dumping the pressurized air overboard. This might be u= seful in the case of an engine fire or other contamination of the inlet air=E2= =80=A6not common, but could really ruin your day if it happened at altitude.= > =20 > So why no heat? If you haven=E2=80=99t done so, it would be very benefici= al to verify that the controls/components discussed work as described above.= IF there are leaks or the system is not connected/configured correctly, all= bets are off. > =20 > The next task, assuming the system is plumbed and operating correctly, is a= ctually generating some heat=E2=80=A6especially up where Dico lives=E2=80=A6= At low power settings, the air coming directly off the turbochargers is not= hot. Your choices (via the cabin temperature control) of compressed air for= pressurization are cool and cold. 25=E2=80=9D of MP is about the minimum th= at will maintain cabin pressurization, and the compressed air off the turbos= is just a bit above ambient temperature. Above 32=E2=80=9D of MP, the exit a= ir is approaching 200 degrees and will keep the cockpit toasty in any condit= ions I=E2=80=99ve seen to date=E2=80=A6but I don=E2=80=99t like to run my en= gine at that high a power setting. So to answer your specific question, heat= the cabin by: > 1) Ensuring the cabin pressure dump control is closed, and not leakin= g air/heat out the dump vent. > 2) Set the cabin temperature control to full hot > 3) Increase engine power (MP), with care to the engine, to get the ne= eded heat. > Note: I=E2=80=99ve actually taken to running the MP between 29-30=E2=80=9D= during the winter time just to keep Judy warm and happy. A good investment=E2= =80=A6 =20 > =20 > Just a last bit of information to =E2=80=9Cpolish off=E2=80=9D the system:= The flow of high pressure air into the cockpit is =E2=80=9Cunregulated=E2=80= =9D as long as the dump control is closed, and although relatively constant,= is subject to changes in both pressure and flow rate depending on engine po= wer setting. The cockpit pressure is maintained by controlling the outflow (= controlled leakage) of air through the Dukes controller mounted in a =E2=80=9C= bucket=E2=80=9D under the rear seat. This is an electrically-controlled exha= ust valve and takes some time to adjust to flow and pressure changes. It=E2=80= =99s therefore easy to =E2=80=9Cget ahead=E2=80=9D of the pressurization sys= tem by rapidly changing the engine power setting. Most of us have learned to= compensate for this, but if you=E2=80=99re getting a lot of ear-popping and= complaints from your passengers, try changing the engine power more gradual= ly, especially at level-off and start of descent. =E2=80=A6And I=E2=80=99m s= ure you=E2=80=99ve all discovered by now what happens if you pull the engine= back to below 25=E2=80=9D MP or so while at altitude? The air in the cabin a= ctually back-flows through the engine and the cabin altitude goes quickly to= the outside pressure altitude. Solution: Keep the MP above 25=E2=80=9D unti= l you=E2=80=99re down out of the flight levels; then slowly bring it back mo= re if needed=E2=80=A6 > =20 > Hope this helps! > =20 > Bob > =20 > =20 > > -- > For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.htm= l --Apple-Mail-5F670ABA-433D-4AE3-AF39-F5E6271FCFA9 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
It is normal to fly with a= c on.

Jeff

Sent from my iPad

O= n Nov 11, 2012, at 11:10 AM, <bronnenmeier@GROBSYSTEMS.COM> wrote:

Dear subscribers,

 

<= p class=3D"MsoNormal">Since we are talking about c= abin heat I got another question. What cabin temperature do you get from you= r turbos on the cool side (after the intercoolers and the additional heat ex= changer in the front)?

 

I put my cool air supply hose in an additional fireproof j= acket that has additional insulation inside (see picture) =E2=80=93 the inte= nsion was to insulate against engine heat and get nice cool cabin air. =

 = ;

At higher= power settings (32 MAP, TIT1620) the cool cabin air is about 100F. This mea= ns flying in the sun even in the high teens with OAT around 20F it still get= s really warm in the cabin and I turn on the AC every now and then.

 

Is this norm= al? Any input is appreciated.

 

<= span style=3D"font-size:11.0pt;font-family:"Calibri","sans-se= rif";color:#1F497D">Ralf

 

From: Jack Morgan [mailto:jm= organ1023@comcast.net]
Sent: Friday, November 09, 2012 8:45 AMTo: lml@lancaironline.net
Subject: Dukes pressurization controller

<= /div>

 

Just a quick note on the controller. Bob's excellent description below is a= ll good. The Dukes controller is an "aneroid" controller which needs no elec= tric power to operate once the airport elevation is set.

=

The electrical control for altitude setting in the ca= bin controls an electric motor in the controller which sets the aneroid so t= hat it controls cabin pressure to just above the set airport altitude. This i= nsures no pressurization is present at landing. Once set, an electrical fail= ure will not cause any problem for the cabin pressurization system.

 

Jack Morgan

 

On Nov 9, 2012, at 6:01 AM= , Lancair Mailing List wrote:


= Subject:&n= bsp;RE: [LML] IVP cabin heat

Date: November 8, 2012 3:16:51 PM EST

 

Dico,

 

=

I=E2=80=99ll answer vi= a the LML as this may be of interest to other Lancair owners/operators.

 

First the disclaimer: The description below covers Lancair IV-Ps= built using the parts provided by Lancair, and following the building manua= l. I have seen a couple of other configurations out there=E2=80=A6the produc= t of =E2=80=9Cindividualism,=E2=80=9D and occasionally better ideas=E2=80=A6= So check to be sure your system is plumbed as described below before trying= these things.

 

The IV-P uses bleed air from the engine turbo= chargers to both pressurize and heat the cockpit. The compressed air pipe ex= iting each turbocharger has a port added to tap off some of the air for the c= abin. (By the way, this air has run through the turbochargers, but does not y= et have any fuel added, so is breathable.) This port should have a =E2=80=9C= sonic nozzle=E2=80=9D either welded to the port itself, or installed in the S= CAT/SCEET line that=E2=80=99s attached. The sonic nozzle provides a relative= constant flow of air to the cabin heating/pressurization system over the ty= pical range of pressure in the turbocharger system (typically 25=E2=80=9D-38= =E2=80=9D MP at cruise power settings). Depending on the power setting (MP),= this compressed air is near ambient temperature to quite hot (200+ degrees)= , and is the =E2=80=9Chot=E2=80=9D feed for the cabin heating/pressurization= system. It is routed via SCAT/SCEET ducting to a flow controller (a gold-an= odized round canister a bit smaller than a coffee can) mounted to the top en= gine-side of the firewall.

 

The cabin heating/pressurization= system has a second =E2=80=9Ccool=E2=80=9D feed that starts with an additio= nal port welded to the engine inlet air ducting downstream of the large inte= rcoolers on each side of the engine. These ports are connected with SCAT tub= ing to a third intercooler on the forward left chin of the engine, opposite t= he alternator. For the =E2=80=9Ccool=E2=80=9D feed, compressed air passes th= rough the side intercoolers, then through this third intercooler and then vi= a a single SCAT tube to the flow controller. Note that both hot and cool fee= ds are =E2=80=9Crelative.=E2=80=9D The hot side can yield luke-warm air i= f the engine power is low, and the cool side is, at best, a few degrees abov= e ambient; usually not cool at all in Florida in the summertime.=

 =

The above compressed air is fed into the cabin directly from the flow c= ontroller on the firewall. With the cabin temperature control in the cold po= sition, flow from the hot side (above) is completely blocked and all pressur= ization air is being fed into the cockpit from the cool side. With the tempe= rature control in the hot position, the cool side feed is blocked and the ho= t side feed is fully opened. As a side note, the flow controller has a secon= d function that=E2=80=99s important. The =E2=80=9Cpressurization control=E2=80= =9D in the cockpit is connected to a flapper valve in the flow controller th= at alternatively opens a port allowing pressurized air to flow into the cock= pit (normal operation) and closes a =E2=80=9Cdump port=E2=80=9D that feeds a= ir, via a SCAT tube, down the forward side of the firewall to the engine exh= aust area. When in the dump position, this valve opens the dump port and clo= ses the port into the cabin, dumping the pressurized air overboard. This mig= ht be useful in the case of an engine fire or other contamination of the inl= et air=E2=80=A6not common, but could really ruin your day if it happened at a= ltitude.

 

So why no heat?  If you haven=E2=80=99t done so, it would be very benefic= ial to verify that the controls/components discussed work as described above= . IF there are leaks or the system is not connected/configured correctly, al= l bets are off.

 

The next task, assuming the system is plumb= ed and operating correctly, is actually generating some heat=E2=80=A6especia= lly up where Dico lives=E2=80=A6 At low power settings, the air coming direc= tly off the turbochargers is not hot. Your choices (via the cabin temperatur= e control) of compressed air for pressurization are cool and cold. 25=E2=80=9D= of MP is about the minimum that will maintain cabin pressurization, and the= compressed air off the turbos&nbs= p;is just a bit above ambient temperature. Above 32=E2=80=9D of MP, t= he exit air is approaching 200 degrees and will keep the cockpit toasty in a= ny conditions I=E2=80=99ve seen to date=E2=80=A6but I don=E2=80=99t like to r= un my engine at that high a power setting. So to answer your specific questi= on, heat the cabin by:

1)  &= nbsp;   <= span style=3D"font-size:11.0pt;font-family:"Calibri","sans-se= rif";color:#1F497D">Ensuring the cabin pressure dump control is closed,= and not leaking air/heat out the dump vent.

2)      Set the cabin temperature con= trol to full hot

=

   &= nbsp;  Increase engine power (MP), with care to the engine, to g= et the needed heat.

<= span style=3D"font-size:11.0pt;font-family:"Calibri","sans-se= rif";color:#1F497D">Note:  I=E2=80=99ve actually taken to running the MP between 29-30=E2=80= =9D during the winter time just to keep Judy warm and happy. A good investme= nt=E2=80=A6 <grin> &= nbsp;

 

Just a last bit of information to =E2=80=9Cpolish off= =E2=80=9D the system: The flow of high pressure air into the cockpit is =E2=80= =9Cunregulated=E2=80=9D as long as the dump control is closed, and although r= elatively constant, is subject to changes in both pressure and flow rate dep= ending on engine power setting. The cockpit pressure is maintained by contro= lling the outflow (controlled leakage) of air through the Dukes controller m= ounted in a =E2=80=9Cbucket=E2=80=9D under the rear seat. This is an electri= cally-controlled exhaust valve and takes some time to adjust to flow and pre= ssure changes. It=E2=80=99s therefore easy to =E2=80=9Cget ahead=E2=80=9D of= the pressurization system by rapidly changing the engine power setting. Mos= t of us have learned to compensate for this, but if you=E2=80=99re getting a= lot of ear-popping and complaints from your passengers, try changing the en= gine power more gradually, especially at level-off and start of descent. =E2= =80=A6And I=E2=80=99m sure you=E2=80=99ve all discovered by now what happens= if you pull the engine back to below 25=E2=80=9D MP or so while at altitude= ? The air in the cabin actually back-flows through the engine and the cabin a= ltitude goes quickly to the outside pressure altitude. Solution: Keep the MP= above 25=E2=80=9D until you=E2=80=99re down out of the flight levels; then s= lowly bring it back more if needed=E2=80=A6

=

 

Hope this helps= !

 

Bob

 

&nb= sp;

=
<engine 2.jpg>
= --Apple-Mail-5F670ABA-433D-4AE3-AF39-F5E6271FCFA9--