X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 08 Nov 2012 15:16:51 -0500 Message-ID: X-Original-Return-Path: Received: from tx2outboundpool.messaging.microsoft.com ([65.55.88.12] verified) by logan.com (CommuniGate Pro SMTP 6.0c2) with ESMTPS id 5868962 for lml@lancaironline.net; Thu, 08 Nov 2012 12:27:10 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.55.88.12; envelope-from=rpastusek@htii.com Received: from mail167-tx2-R.bigfish.com (10.9.14.248) by TX2EHSOBE009.bigfish.com (10.9.40.29) with Microsoft SMTP Server id 14.1.225.23; Thu, 8 Nov 2012 17:26:36 +0000 Received: from mail167-tx2 (localhost [127.0.0.1]) by mail167-tx2-R.bigfish.com (Postfix) with ESMTP id DB3C1160097 for ; Thu, 8 Nov 2012 17:26:36 +0000 (UTC) X-Forefront-Antispam-Report: CIP:157.56.245.5;KIP:(null);UIP:(null);IPV:NLI;H:CH1PRD0710HT002.namprd07.prod.outlook.com;RD:none;EFVD:NLI X-SpamScore: -10 X-BigFish: PS-10(zzc85fhc430I1453I1470M4015I328cM14ffIzz1de0h1202h1d1ah1d2ahzz17326ah8275bh8275dhz31h2a8h668h839hd25hf0ah1288h12a5h12bdh137ah1441h1504h1537h153bh15d0l1155h) Received-SPF: softfail (mail167-tx2: transitioning domain of htii.com does not designate 157.56.245.5 as permitted sender) client-ip=157.56.245.5; envelope-from=rpastusek@htii.com; helo=CH1PRD0710HT002.namprd07.prod.outlook.com ;.outlook.com ; Received: from mail167-tx2 (localhost.localdomain [127.0.0.1]) by mail167-tx2 (MessageSwitch) id 135239559376772_31577; Thu, 8 Nov 2012 17:26:33 +0000 (UTC) Received: from TX2EHSMHS008.bigfish.com (unknown [10.9.14.235]) by mail167-tx2.bigfish.com (Postfix) with ESMTP id 101C0A014A for ; Thu, 8 Nov 2012 17:26:33 +0000 (UTC) Received: from CH1PRD0710HT002.namprd07.prod.outlook.com (157.56.245.5) by TX2EHSMHS008.bigfish.com (10.9.99.108) with Microsoft SMTP Server (TLS) id 14.1.225.23; Thu, 8 Nov 2012 17:26:31 +0000 Received: from CH1PRD0710MB367.namprd07.prod.outlook.com ([169.254.11.72]) by CH1PRD0710HT002.namprd07.prod.outlook.com ([10.255.152.37]) with mapi id 14.16.0233.002; Thu, 8 Nov 2012 17:26:30 +0000 From: Robert R Pastusek X-Original-To: Lancair Mailing List Subject: RE: [LML] IVP cabin heat Thread-Topic: [LML] IVP cabin heat Thread-Index: AQHNvW9P0jXtGEvo50yx+k1Et4fgbZfgHrCw X-Original-Date: Thu, 8 Nov 2012 17:26:30 +0000 X-Original-Message-ID: <41361035E6613244A377D5AC3BF5EFDD420F4009@CH1PRD0710MB367.namprd07.prod.outlook.com> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [72.66.86.7] Content-Type: multipart/alternative; boundary="_000_41361035E6613244A377D5AC3BF5EFDD420F4009CH1PRD0710MB367_" MIME-Version: 1.0 X-Original-Return-Path: rpastusek@htii.com X-OriginatorOrg: htii.com --_000_41361035E6613244A377D5AC3BF5EFDD420F4009CH1PRD0710MB367_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Dico, I'll answer via the LML as this may be of interest to other Lancair owners/= operators. First the disclaimer: The description below covers Lancair IV-Ps built usin= g the parts provided by Lancair, and following the building manual. I have = seen a couple of other configurations out there...the product of "individua= lism," and occasionally better ideas... 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 turbochargers to both pressurize an= d 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= has run through the turbochargers, but does not yet have any fuel added, s= o is breathable.) This port should have a "sonic nozzle" either welded to t= he port itself, or installed in the SCAT/SCEET line that's attached. The so= nic nozzle provides a relative constant flow of air to the cabin heating/pr= essurization system over the typical range of pressure in the turbocharger = system (typically 25"-38" MP at cruise power settings). Depending on the po= wer setting (MP), this compressed air is near ambient temperature to quite = hot (200+ degrees), and is the "hot" feed for the cabin heating/pressurizat= ion system. It is routed via SCAT/SCEET ducting to a flow controller (a gol= d-anodized round canister a bit smaller than a coffee can) mounted to the t= op engine-side of the firewall. The cabin heating/pressurization system has a second "cool" feed that start= s with an additional port welded to the engine inlet air ducting downstream= of the large intercoolers on each side of the engine. These ports are conn= ected with SCAT tubing to a third intercooler on the forward left chin of t= he engine, opposite the alternator. For the "cool" feed, compressed air pas= ses through the side intercoolers, then through this third intercooler and = then via a single SCAT tube to the flow controller. Note that both hot and = cool feeds are "relative." The hot side can yield luke-warm air if the engi= ne power is low, and the cool side is, at best, a few degrees above ambient= ; usually not cool at all in Florida in the summertime. The above compressed air is fed into the cabin directly from the flow contr= oller on the firewall. With the cabin temperature control in the cold posit= ion, flow from the hot side (above) is completely blocked and all pressuriz= ation air is being fed into the cockpit from the cool side. With the temper= ature 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 seco= nd function that's important. The "pressurization control" in the cockpit i= s connected to a flapper valve in the flow controller that alternatively op= ens a port allowing pressurized air to flow into the cockpit (normal operat= ion) and closes a "dump port" that feeds air, via a SCAT tube, down the for= ward side of the firewall to the engine exhaust area. When in the dump posi= tion, this valve opens the dump port and closes the port into the cabin, du= mping the pressurized air overboard. This might be useful in the case of an= engine fire or other contamination of the inlet air...not common, but coul= d really ruin your day if it happened at altitude. So why no heat? If you haven't done so, it would be very beneficial to ver= ify that the controls/components discussed work as described above. IF ther= e are leaks or the system is not connected/configured correctly, all bets a= re off. The next task, assuming the system is plumbed and operating correctly, is a= ctually generating some heat...especially up where Dico lives... At low pow= er settings, the air coming directly off the turbochargers is not hot. Your= choices (via the cabin temperature control) of compressed air for pressuri= zation are cool and cold. 25" of MP is about the minimum that will maintain= cabin pressurization, and the compressed air off the turbos is just a bit = above ambient temperature. Above 32" of MP, the exit air is approaching 200= degrees and will keep the cockpit toasty in any conditions I've seen to da= te...but I don't like to run my engine 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 leaking= 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 nee= ded heat. Note: I've actually taken to running the MP between 29-30" during the wint= er time just to keep Judy warm and happy. A good investment... Just a last bit of information to "polish off" the system: The flow of high= pressure air into the cockpit is "unregulated" 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 power setting. The cockpit pres= sure is maintained by controlling the outflow (controlled leakage) of air t= hrough the Dukes controller mounted in a "bucket" under the rear seat. This= is an electrically-controlled exhaust valve and takes some time to adjust = to flow and pressure changes. It's therefore easy to "get ahead" of the pre= ssurization system by rapidly changing the engine power setting. Most of us= have learned to compensate for this, but if you're getting a lot of ear-po= pping and complaints from your passengers, try changing the engine power mo= re gradually, especially at level-off and start of descent. ...And I'm sure= you've all discovered by now what happens if you pull the engine back to b= elow 25" MP or so while at altitude? The air in the cabin actually back-flo= ws through the engine and the cabin altitude goes quickly to the outside pr= essure altitude. Solution: Keep the MP above 25" until you're down out of t= he flight levels; then slowly bring it back more if needed... Hope this helps! Bob Hi All, I've not flown much in the winter with my IVP so I'm not too familiar with = the heating system. I notice that there is a "temperature" and "heat/defro= st" pull on the co-pilot side. We were up flying the other day and I thoug= ht that I would give these handles a tug to see what would happen.... while= I got the air to really blow in the cockpit (from up the front window), I = didn't really sense much heat. I pulled the temperature know out and left = it for a couple minutes and still didn't notice anything. I'm just wonder= ing how much heat the IVP throws off? Also, what are the correct settings = for full heat? Thanks, Dico --_000_41361035E6613244A377D5AC3BF5EFDD420F4009CH1PRD0710MB367_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Dico,

 

I’ll answer via the LML as this may be of int= erest 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 manual. I have seen a couple of other configurations out ther= e…the product of “individualism,” and occasionally better= ideas… 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 turbocharge= rs to both pressurize and 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 has run through the turbochargers, but doe= s not yet have any fuel added, so is breathable.) This port should have a &= #8220;sonic nozzle” either welded to the port itself, or installed in the SCAT/SCEET line that’s attached. Th= e sonic nozzle provides a relative constant flow of air to the cabin heatin= g/pressurization system over the typical range of pressure in the turbochar= ger system (typically 25”-38” 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 = 220;hot” feed for the cabin heating/pressurization system. It is rout= ed via SCAT/SCEET ducting to a flow controller (a gold-anodized round canister a bit smaller than a coffee can) mounted to t= he top engine-side of the firewall.

 

The cabin heating/pressurization system has a secon= d “cool” feed that starts with an additional port welded to the= engine inlet air ducting downstream of the large intercoolers on each side of the= engine. These ports are connected with SCAT tubing to a third intercooler = on the forward left chin of the engine, opposite the alternator. For the &#= 8220;cool” feed, compressed air passes through the side intercoolers, then through this third intercooler and the= n via a single SCAT tube to the flow controller. Note that both hot and coo= l feeds are “relative.” The hot side can yield luke-warm air if the engine power is low, and= the cool side is, at best, a few degrees above ambient; usually not cool a= t all in Florida in the summertime.

 

The above compressed air is fed into the cabin dire= ctly from the flow controller on the firewall. With the cabin temperature control in the cold position, flow from the hot side (above) is completely= blocked and all pressurization air is being fed into the cockpit from the = cool side. With the temperature control in the hot position, the cool side = feed is blocked and the hot side feed is fully opened. As a side note, the flow controller has a second fun= ction that’s important. The “pressurization control” in t= he cockpit is connected to a flapper valve in the flow controller that alte= rnatively opens a port allowing pressurized air to flow into the cockpit (normal operation) and closes a “dump portR= 21; that feeds air, via a SCAT tube, down the forward side of the firewall = to the engine exhaust area. When in the dump position, this valve opens the= dump port and closes the port into the cabin, dumping the pressurized air overboard. This might be useful in the case of= an engine fire or other contamination of the inlet air…not common, b= ut could really ruin your day if it happened at altitude.

 

So why no heat?&nb= sp; If you haven’t done so, it would be very beneficial to verify = that the controls/components discussed work as described above. IF there ar= e leaks or the system is not connected/configured correctly, all bets are o= ff.

 

The next task, assuming the system is plumbed and o= perating correctly, is actually generating some heat…especially up where Dico lives… At low power settings, the air coming directly off= the turbochargers is not hot. Your choices (via the cabin temperature cont= rol) of compressed air for pressurization are cool and cold. 25” of M= P is about the minimum that will maintain cabin pressurization, and the compressed air off the turb= os is just a bit above ambient temperature. Above 32” of MP, t= he exit air is approaching 200 degrees and will keep the cockpit toasty in = any conditions I’ve seen to date…but I don’t like to run my engine at that high a power setting. So to answer your spec= ific question, heat the cabin by:

1) = ;     Ensuring the cabin pressure dump control is= closed, and not leaking air/heat out the dump vent.

2) = ;     Set the cabin temperature control to full h= ot

3) = ;     Increase engine power (MP), with care to th= e engine, to get the needed heat.

Note:  I’ve actually taken to = running the MP between 29-30” during the winter time just to keep Jud= y warm and happy. A good investment… <grin>  

 

Just a last bit of information to “polish off= ” the system: The flow of high pressure air into the cockpit is ̶= 0;unregulated” as long as the dump control is closed, and although relatively constant, i= s subject to changes in both pressure and flow rate depending on engine pow= er setting. The cockpit pressure is maintained by controlling the outflow (= controlled leakage) of air through the Dukes controller mounted in a “bucket” under the rear seat= . This is an electrically-controlled exhaust valve and takes some time to a= djust to flow and pressure changes. It’s therefore easy to “get= ahead” of the pressurization system by rapidly changing the engine power setting. Most of us have learned to compensate for this, = but if you’re getting a lot of ear-popping and complaints from your p= assengers, try changing the engine power more gradually, especially at leve= l-off and start of descent. …And I’m sure you’ve all discovered by now what happens if you pull the engine bac= k to below 25” MP or so while at altitude? The air in the cabin actua= lly back-flows through the engine and the cabin altitude goes quickly to th= e outside pressure altitude. Solution: Keep the MP above 25” until you’re down out of the flight levels; t= hen slowly bring it back more if needed…

 

Hope this helps!

 

Bob

 

Hi All,

I've not flown much in the winter with my IVP so I'm not too familiar with = the heating system.  I notice that there is a "temperature" = and "heat/defrost" pull on the co-pilot side.  We were up fl= ying the other day and I thought that I would give these handles a tug to see what would happen.... while I got the air to really blow in t= he cockpit (from up the front window), I didn't really sense much heat.&nbs= p; I pulled the temperature know out and left it for a couple minutes and s= till didn't notice anything.   I'm just wondering how much heat the IVP throws off?  Also, what are the corre= ct settings for full heat?

Thanks,

Dico

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