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dlm46007(at)cox.net
Guest

Posted: Tue Apr 25, 2006 4:37 am Post subject: tunnel heat

Anyone have a reason for the tunnel heat? what temperature?

---

rick.conti(at)boeing.com
Guest

Posted: Tue Apr 25, 2006 5:28 am Post subject: tunnel heat

This topic was discussed in the past.  I called the guy who posted the

subject.  He is positive the heat is from the engine cooling which is in

the center of the lower cowling.  He is also sure it is not the engine

exhaust.  I look into venting my tunnel.  Easy to vent at the rear to

let hot air out, but not so easy installing an inlet.  I opted for

insulation.  I made a false floor for the fuel pump assembly and

installed 1" of insulation along the bottom of the fuselage, full length

of the tunnel.  One inch was too much below the torque tubes, used 1/4"

and 1/8" in those locations.  I have not flown, so I can only hope this

works.



Thank You

Rick Conti

Senior Engineering Manager

The Boeing Company

          office: 703 - 414 - 6141

blackberry: 571 - 215 - 6134

--

Tim(at)MyRV10.com
Guest

Posted: Tue Apr 25, 2006 5:52 am Post subject: tunnel heat

David,

Don't take this with the wrong tone, as I don't mean it

as you might hear it, but....



Are you saying you've never heard of the tunnel heat issue

that was discussed in the past?



If so, I can try to post a short history and possible solutions.



Tim Olson - RV-10 N104CD - Flying

do not archive

David McNeill wrote:

[quote] 

 

 Anyone have a reason for the tunnel heat? what temperature?

 ---

GRANSCOTT(at)aol.com
Guest

Posted: Tue Apr 25, 2006 5:52 am Post subject: tunnel heat

When I flew 410RV at Lakeland airport, the tunnel is pretty darn hot, I  said something to Gus and he said it's warm but you get use to it...I'd guess  410's about hot enough at low altitude to burn your skin or irritate if you stay  in contact with it...don't know if anyone else noticed this or it was just me  looking for something...

  

 Patrick Scott

  

 do not archive

rvbuilder(at)sausen.net
Guest

Posted: Tue Apr 25, 2006 6:11 am Post subject: tunnel heat

  This has been an ongoing problem, lot's of stuff in the archives about it.  Not sure if anyone has really determined 100% what the cause is but there has been lot's of speculation and remediation techniques discussed.  Some of the possible problems are:

 

 -Air leakage through the heat boxes on the firewall

 -Radiated heat via the firewall

-Radiated heat from the exhaust/engine cooling

 -radiated heat from the SCAT tube running through the tunnel

 

   I believe Tim used silicon baffle material as a thermal break when he attached the firewall cabin heat vent boxes which is probably a good idea.  I used a ceramic paint additive and painted the inside of the firewall, tunnel, and floor.  I also sprayed my acoustic material in the same areas which may add some additional insulating capacity (doubtful but anything helps).  I may also use the standard firewall insulation but that stuff doesn't work very well unless you can keep it completely air sealed against the firewall.  The last thing I am going to try to avoid this problem is to use insulated duct instead of regular SCAT.  The stuff is hard to find, and a lot more expensive, but heat is a serious problem living in Texas (at least to someone from Wisconsin ) and I really want to keep it controlled.

 

 Michael Sausen

 RV-10 #352 Working on Fuselage

 Do Not Archive

 

 --

Tdawson(at)avidyne.com
Guest

Posted: Tue Apr 25, 2006 6:30 am Post subject: tunnel heat

Michael, can you report a source for your insulated SCAT?  

   

TDT  

40025  

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of RV Builder (Michael Sausen)

 Sent: Tuesday, April 25, 2006 10:09 AM

 To: rv10-list(at)matronics.com

 Subject: RE: tunnel heat  

  

   

  This has been an ongoing problem, lot's of stuff in the archives about it.  Not sure if anyone has really determined 100% what the cause is but there has been lot's of speculation and remediation techniques discussed.  Some of the possible problems are:

 

 -Air leakage through the heat boxes on the firewall

 -Radiated heat via the firewall

 -Radiated heat from the exhaust/engine cooling

 -radiated heat from the SCAT tube running through the tunnel

 

   I believe Tim used silicon baffle material as a thermal break when he attached the firewall cabin heat vent boxes which is probably a good idea.  I used a ceramic paint additive and painted the inside of the firewall, tunnel, and floor.  I also sprayed my acoustic material in the same areas which may add some additional insulating capacity (doubtful but anything helps).  I may also use the standard firewall insulation but that stuff doesn't work very well unless you can keep it completely air sealed against the firewall.  The last thing I am going to try to avoid this problem is to use insulated duct instead of regular SCAT.  The stuff is hard to find, and a lot more expensive, but heat is a serious problem living in Texas (at least to someone from Wisconsin ) and I really want to keep it controlled.

 

 Michael Sausen

 RV-10 #352 Working on Fuselage

 Do Not Archive

 

 --

tgesele(at)optonline.net
Guest

Posted: Tue Apr 25, 2006 6:56 am Post subject: tunnel heat

Has anyone considered installing a small  blast tube off the baffles and dumping the air directly into the tunnel? Seems  like coupling that with some firewall insulation on the  forward side would resolve the heat situation (or am I missing  something)?

  

 Tom Gesele #473

  	  Quote:

rvbuilder(at)sausen.net
Guest

Posted: Tue Apr 25, 2006 7:13 am Post subject: tunnel heat

  Umm, where did I put that link.  The problem  I've had is finding anything insulated in 2" and the only thing I have been  able to come up with is a product called Flex-vest.  I can't seem to find a  link that has a price again but most sites that sell it will give a quote.   I believe when I looked at it a couple months ago it was around $20 a foot,  yikes!  Google Flex-vest and you should get some hits.  Here is an  example link:

  

 <http://www.flexaust.com/industrial/product_selector.asp?id=61&detail=1>

  

   I might check with a local HVAC guy and see if there  is something more common for less money.  I would think you could find some  flexible & insulated ducting near that size for the newer high velocity HVAC  systems.

  

   Another option is to take the standard SCAT and wrap  it with common pipe insulating wrap.

  

  

Michael Sausen 

RV-10 #352 Working on  Fuselage 

Do Not Archive 

Recent RV-10 Build Activity

  



   From: owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Tim  Dawson-Townsend

Sent: Tuesday, April 25, 2006 9:29 AM

To:  rv10-list(at)matronics.com

Subject: RE: tunnel  heat

 

  

Michael, can you report  a source for your insulated SCAT? 

  

TDT 

40025 

     

 

From:  owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of RV Builder (Michael  Sausen)

Sent: Tuesday, April  25, 2006 10:09 AM

To:  rv10-list(at)matronics.com

Subject: RE: tunnel  heat

 

  

  This has been an ongoing problem, lot's of stuff  in the archives about it.  Not sure if anyone has really determined 100%  what the cause is but there has been lot's of speculation and remediation  techniques discussed.  Some of the possible problems are:



-Air  leakage through the heat boxes on the firewall

-Radiated heat via the  firewall

-Radiated heat from the exhaust/engine cooling

-radiated heat  from the SCAT tube running through the tunnel



  I believe Tim used  silicon baffle material as a thermal break when he attached the firewall cabin  heat vent boxes which is probably a good idea.  I used a ceramic paint  additive and painted the inside of the firewall, tunnel, and floor.  I also  sprayed my acoustic material in the same areas which may add some additional  insulating capacity (doubtful but anything helps).  I may also use the  standard firewall insulation but that stuff doesn't work very well unless you  can keep it completely air sealed against the firewall.  The last thing I  am going to try to avoid this problem is to use insulated duct instead of  regular SCAT.  The stuff is hard to find, and a lot more expensive, but  heat is a serious problem living in Texas (at  least to someone from Wisconsin ) and I really want to keep it  controlled.



Michael Sausen

RV-10 #352 Working on Fuselage

Do Not  Archive



--

rvbuilder(at)sausen.net
Guest

Posted: Tue Apr 25, 2006 7:20 am Post subject: tunnel heat

  One problem  with that solution is the air needs someplace to go.  Either into the cabin or back  into the cowl.  I will try to airseal my cabin as much as possible to  provide for a quieter and more controlled environment and have an exhaust flap,  if needed, (similar to what modern autos have) in the rear  bulkhead.

  

   Also, every  additional firewall penetration will speed up a fire spreading into the  cockpit.

  

   Someone suggested  a small computer fan to circulate air through the tunnel.  This is probably  the best idea after trying to prevent the heat as much as possible.

  

  

Michael Sausen 

RV-10 #352 Working on  Fuselage 

Do Not Archive 

Recent RV-10 Build Activity

  



   From: owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Tom  Gesele

Sent: Tuesday, April 25, 2006 9:26 AM

To:  rv10-list(at)matronics.com

Subject: RE: tunnel  heat

 

 Has anyone considered installing a small  blast tube off the baffles and dumping the air directly into the tunnel? Seems  like coupling that with some firewall insulation on the  forward side would resolve the heat situation (or am I missing  something)?

  

 Tom Gesele #473

  	  Quote:

Tim(at)MyRV10.com
Guest

Posted: Tue Apr 25, 2006 7:38 am Post subject: tunnel heat

Mike did a good job on this post.  I personally see that the

heat from the exhaust, with the heater valve closed, would

tend to build up hot due to the slow moving hot air and small

leakage at the valve to the outside.  Then those heater valve

boxes get hot, and it transfers into the tunnel area, esp.

by the firewall.  When you're running cabin heat, you'd

maybe get a little less at the heater valve since the air

is flowing more, but you may get more radiating from the

SCAT in the tunnel area.  Ventilating the tunnel may work, but

you would want to ensure no moisture enters or you may

end up with corrosion tendencies.



What I did was use 1/8" silicone baffle gasket material

to make a gasket between the heater box and firewall.  This

should help prevent the metal to metal conductive transfer

a bit.  I checked out Phenolic, but it's temp rating was

really low, and the silicone baffle is good for 500 deg +

or so.   Then, in addition, I have a 1" or maybe it's 1.25"

SCAT flange attached to my right rear baffle and the SCAT

tube just runs down and connects to the firewall in a way

that allows it to blast air onto the heater valves.  This

idea was had after talking to Randy, who was one of the few

people not reporting extremely hot tunnels.  Randy had a

blast tube that ran to his fuel pump (engine mounted) if

I remember right, and he felt that maybe he had no problems

because the excess air from the fuel pump area was also

cooling the nearby vent boxes.   So I tried to just use

a tube to do that directly.   In my experience, on the SNF

trip, I pulled my shoes and was able to hold my foot against

the tunnel indefinitely, but it was still "hot".  Some people

had reported it would definitely burn them, but mine is

not that hot.  In addition, I have reflective firewall insulation

lining my tunnel which may help too.



Other things to consider:  If your tunnel is hot, your fuel

lines in there will have a higher likelyhood of producing

fuel vapor.   If you use the standard fuel valve, you

still may be fine, but during times when you use rear heat

you'll be running hot air next to your valve.  In my install,

the SCAT runs next to only the long shaft that runs the

fuel valve.



One other builder got something like 6" exhaust extensions that

moved the exhaust away from the belly a bit.  He said it

got cooler and quieter. I believe him, but, I think 6" would

be a little long, and the exhaust is still going to go right

past the bottom corner of the firewall....it's just going to

exit further away.



And a note on defroster fans.  I had thought that I may want

to pipe hot air from the heater system or tunnel up to

my defroster fan.  I don't think it's worth it anymore, and here's

why.  In the winter you turn on the heat.  The heat flows

up under the panel area anyway. My GRT EIS easily was reading

in the 90-110 deg. range in the panel.  So all that hot

air is readily available to be blown on the windshield.  I leave

my fan on year round, since in the summer it might be best to

exhaust some of that hot air from my avionics anyway.



So that's more than you wanted to read on heat today. 

Tim Olson - RV-10 N104CD - Flying

do not archive

RV Builder (Michael Sausen) wrote:

[quote]   This has been an ongoing problem, lot's of stuff in the archives about 

 it.  Not sure if anyone has really determined 100% what the cause is but 

 there has been lot's of speculation and remediation techniques 

 discussed.  Some of the possible problems are:

 

 -Air leakage through the heat boxes on the firewall

 -Radiated heat via the firewall

 -Radiated heat from the exhaust/engine cooling

 -radiated heat from the SCAT tube running through the tunnel

 

   I believe Tim used silicon baffle material as a thermal break when he 

 attached the firewall cabin heat vent boxes which is probably a good 

 idea.  I used a ceramic paint additive and painted the inside of the 

 firewall, tunnel, and floor.  I also sprayed my acoustic material in the 

 same areas which may add some additional insulating capacity (doubtful 

 but anything helps).  I may also use the standard firewall insulation 

 but that stuff doesn't work very well unless you can keep it completely 

 air sealed against the firewall.  The last thing I am going to try to 

 avoid this problem is to use insulated duct instead of regular SCAT.  

 The stuff is hard to find, and a lot more expensive, but heat is a 

 serious problem living in Texas (at least to someone from Wisconsin ) 

 and I really want to keep it controlled.

 

 Michael Sausen

 RV-10 #352 Working on Fuselage

 Do Not Archive

 

 --

zackrv8

Joined: 14 Jan 2006
Posts: 133

Posted: Tue Apr 25, 2006 8:10 am Post subject: Re: tunnel heat

Well....I'm not at that point of construction yet, but the tunnel heat does concern me.  Looking at many of the Rv10 projects on the web, it seems Van's has the 2 triangular shaped heat valves (same one I have in my RV8) aiming the exhaust port at each other.  This hot air is always pointing at each other until you open the valve for cabin heat.



  Part of the tunnel heat problem could be as what Tim ond others have said...heat conducting through the valve and radiating into the tunnel.  Also, if the heat valve(s) are the very same ones that I bought from Vans (I believe they are), then they don't "seal" very well.  If you have a blast of hot air aiming at them constantly, (try experimenting with the valve in your hand and blow some air with your air hose at the outlet side and see what happens) they could possible leak and that hot air is forced down the tunnel through a "leaky" valve.  Maybe a solution would be to not point the exhaust ports at each other and/or make a gasket to provide a better seal.



  Just a thought but it's possible.   



Zack

_________________
RV8 #80125
RV10 # 40512

flysrv10(at)gmail.com
Guest

Posted: Tue Apr 25, 2006 9:21 am Post subject: tunnel heat

I taped my heater valves shut and the problem is essentially solved

for the time being.  I think that the problem is in the valves.  They

do not seal.  After hearing of the problem, I even created a gasket to

seal the valves when they are shut.  Apprently not good enough.



The solution might be in some talented person with a good machine shop

producing a valve with positive seal.



Do not archive



On 4/25/06, zackrv8 <zackrv8(at)verizon.net> wrote:

 	  Quote: 	
		   



 Well....I'm not at that point of construction yet, but the tunnel heat does concern me.  Looking at many of the Rv10 projects on the web, it seems Van's has the 2 triangular shaped heat valves (same one I have in my RV8) aiming the exhaust port at each other.  This hot air is always pointing at each other until you open the valve for cabin heat.



   Part of the tunnel heat problem could be as what Tim ond others have said...heat conducting through the valve and radiating into the tunnel.  Also, if the heat valve(s) are the very same ones that I bought from Vans (I believe they are), then they don't "seal" very well.  If you have a blast of hot air aiming at them constantly, (try experimenting with the valve in your hand and blow some air with your air hose at the outlet side and see what happens) they could possible leak and that hot air is forced down the tunnel through a "leaky" valve.  Maybe a solution would be to not point the exhaust ports at each other and/or make a gasket to provide a better seal.



   Just a thought but it's possible.



 Zack



 --------

 RV8 #80125

 RV10 # 40512





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=30585#30585

zackrv8

Joined: 14 Jan 2006
Posts: 133

Posted: Tue Apr 25, 2006 9:28 am Post subject: Re: tunnel heat

I'll pass this on to Dave and see what he can come up with.



Zack





The solution might be in some talented person with a good machine shop

producing a valve with positive seal.



Do not archive



On 4/25/06, zackrv8 <zackrv8(at)verizon.net> wrote:

 	  Quote: 	
		   



 Well....I'm not at that point of construction yet, but the tunnel heat does concern me.  Looking at many of the Rv10 projects on the web, it seems Van's has the 2 triangular shaped heat valves (same one I have in my RV8) aiming the exhaust port at each other.  This hot air is always pointing at each other until you open the valve for cabin heat.



   Part of the tunnel heat problem could be as what Tim ond others have said...heat conducting through the valve and radiating into the tunnel.  Also, if the heat valve(s) are the very same ones that I bought from Vans (I believe they are), then they don't "seal" very well.  If you have a blast of hot air aiming at them constantly, (try experimenting with the valve in your hand and blow some air with your air hose at the outlet side and see what happens) they could possible leak and that hot air is forced down the tunnel through a "leaky" valve.  Maybe a solution would be to not point the exhaust ports at each other and/or make a gasket to provide a better seal.



   Just a thought but it's possible.



 Zack



 --------

 RV8 #80125

 RV10 # 40512





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=30585#30585

	
[/quote]

_________________
RV8 #80125
RV10 # 40512

mike(at)cleavelandtool.co
Guest

Posted: Tue Apr 25, 2006 9:40 am Post subject: tunnel heat

I had been planning on a second valve as a "heat dump" so the firewall valve

is cold.  After hearing this it sounds like this is an even better idea.

Really shutting off the heat has always been a problem in the -4.  That

said, any of you that have the engine install done... is there room for

another T valve?



Mike Lauritsen

Cleaveland Aircraft Tool

2225 First St. 

Boone, Iowa 50036

515-432-6794

mike(at)cleavelandtool.com

--

flysrv10(at)gmail.com
Guest

Posted: Tue Apr 25, 2006 9:44 am Post subject: tunnel heat

Great!



Do not archive



On 4/25/06, zackrv8 <zackrv8(at)verizon.net> wrote:

 	  Quote: 	
		   



 I'll pass this on to Dave and see what he can come up with.



 Zack





 The solution might be in some talented person with a good machine shop

 producing a valve with positive seal.



 Do not archive



 On 4/25/06, zackrv8  wrote:



 >

 >

 >  Well....I'm not at that point of construction yet, but the tunnel heat does concern me.  Looking at many of the Rv10 projects on the web, it seems Van's has the 2 triangular shaped heat valves (same one I have in my RV8) aiming the exhaust port at each other.  This hot air is always pointing at each other until you open the valve for cabin heat.

 >

 >    Part of the tunnel heat problem could be as what Tim ond others have said...heat conducting through the valve and radiating into the tunnel.  Also, if the heat valve(s) are the very same ones that I bought from Vans (I believe they are), then they don't "seal" very well.  If you have a blast of hot air aiming at them constantly, (try experimenting with the valve in your hand and blow some air with your air hose at the outlet side and see what happens) they could possible leak and that hot air is forced down the tunnel through a "leaky" valve.  Maybe a solution would be to not point the exhaust ports at each other and/or make a gasket to provide a better seal.

 >

 >    Just a thought but it's possible.

 >

 >  Zack

 >

 >  --------

 >  RV8 #80125

 >  RV10 # 40512

 >

 >

 >

 >

 >  Read this topic online here:

 >

 >  http://forums.matronics.com/viewtopic.php?p=30585#30585

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >



 --------

 RV8 #80125

 RV10 # 40512





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=30611#30611

jesse(at)itecusa.org
Guest

Posted: Tue Apr 25, 2006 10:35 am Post subject: tunnel heat

I have a hard time believing that the scat tubes are causing the tunnel to get so hot.  There is only heat going through them when the heater is on, and then the air is flowing through into the cabin, so the cabin is also heating up.  Am I missing something?  

   

I N256H we have not noticed any excessive heat in the tunnel and it has flown over 200 hours.  We haven’t paid a lot of attention to it, but in that much airtime, I would think the issue would show up.  We didn’t do anything special to insulate it.  

     

Jesse Saint  

I-TEC, Inc.  

jesse(at)itecusa.org (jesse(at)itecusa.org)  

www.itecusa.org  

352-465-4545  

        

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Tim Dawson-Townsend

 Sent: Tuesday, April 25, 2006 9:29 AM

 To: rv10-list(at)matronics.com

 Subject: RE: tunnel heat  

  

   

Michael, can you report a source for your insulated SCAT?  

   

TDT  

40025  

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of RV Builder (Michael Sausen)

 Sent: Tuesday, April 25, 2006 10:09 AM

 To: rv10-list(at)matronics.com

 Subject: RE: tunnel heat  

  

   

  This has been an ongoing problem, lot's of stuff in the archives about it.  Not sure if anyone has really determined 100% what the cause is but there has been lot's of speculation and remediation techniques discussed.  Some of the possible problems are:

 

 -Air leakage through the heat boxes on the firewall

 -Radiated heat via the firewall

 -Radiated heat from the exhaust/engine cooling

 -radiated heat from the SCAT tube running through the tunnel

 

   I believe Tim used silicon baffle material as a thermal break when he attached the firewall cabin heat vent boxes which is probably a good idea.  I used a ceramic paint additive and painted the inside of the firewall, tunnel, and floor.  I also sprayed my acoustic material in the same areas which may add some additional insulating capacity (doubtful but anything helps).  I may also use the standard firewall insulation but that stuff doesn't work very well unless you can keep it completely air sealed against the firewall.  The last thing I am going to try to avoid this problem is to use insulated duct instead of regular SCAT.  The stuff is hard to find, and a lot more expensive, but heat is a serious problem living in Texas (at least to someone from Wisconsin ) and I really want to keep it controlled.

 

 Michael Sausen

 RV-10 #352 Working on Fuselage

 Do Not Archive

 

 --

Tdawson(at)avidyne.com
Guest

Posted: Tue Apr 25, 2006 10:44 am Post subject: tunnel heat

What an airplane that the only thing we have to complain about or discuss is a little extra heat in the tunnel!  

   

TDT

 40025  

Do not archive  

   

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jesse Saint

 Sent: Tuesday, April 25, 2006 2:33 PM

 To: rv10-list(at)matronics.com

 Subject: RE: tunnel heat  

  

   

I have a hard time believing that the scat tubes are causing the tunnel to get so hot.  There is only heat going through them when the heater is on, and then the air is flowing through into the cabin, so the cabin is also heating up.  Am I missing something?  

   

I N256H we have not noticed any excessive heat in the tunnel and it has flown over 200 hours.  We haven’t paid a lot of attention to it, but in that much airtime, I would think the issue would show up.  We didn’t do anything special to insulate it.  

     

Jesse Saint  

I-TEC, Inc.  

jesse(at)itecusa.org (jesse(at)itecusa.org)  

www.itecusa.org  

352-465-4545  

        

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Tim Dawson-Townsend

 Sent: Tuesday, April 25, 2006 9:29 AM

 To: rv10-list(at)matronics.com

 Subject: RE: tunnel heat  

  

   

Michael, can you report a source for your insulated SCAT?  

   

TDT  

40025  

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of RV Builder (Michael Sausen)

 Sent: Tuesday, April 25, 2006 10:09 AM

 To: rv10-list(at)matronics.com

 Subject: RE: tunnel heat  

  

   

  This has been an ongoing problem, lot's of stuff in the archives about it.  Not sure if anyone has really determined 100% what the cause is but there has been lot's of speculation and remediation techniques discussed.  Some of the possible problems are:

 

 -Air leakage through the heat boxes on the firewall

 -Radiated heat via the firewall

 -Radiated heat from the exhaust/engine cooling

 -radiated heat from the SCAT tube running through the tunnel

 

   I believe Tim used silicon baffle material as a thermal break when he attached the firewall cabin heat vent boxes which is probably a good idea.  I used a ceramic paint additive and painted the inside of the firewall, tunnel, and floor.  I also sprayed my acoustic material in the same areas which may add some additional insulating capacity (doubtful but anything helps).  I may also use the standard firewall insulation but that stuff doesn't work very well unless you can keep it completely air sealed against the firewall.  The last thing I am going to try to avoid this problem is to use insulated duct instead of regular SCAT.  The stuff is hard to find, and a lot more expensive, but heat is a serious problem living in Texas (at least to someone from Wisconsin ) and I really want to keep it controlled.

 

 Michael Sausen

 RV-10 #352 Working on Fuselage

 Do Not Archive

 

 --

rvbuilder(at)sausen.net
Guest

Posted: Tue Apr 25, 2006 11:04 am Post subject: tunnel heat

Jesse,

  

   If the vent boxes are leaking heated air  into the SCAT it will indeed radiate heat.  Sounds like you got lucky  and have some tightly closing vent boxes.  Or maybe much in the same  way Randy doesn't have much of a problem, you did something in  the engine compartment to negate it.  Like others have said it is probably a  combination of different things, but it is a problem and it does exist on others  -10's as has been reported. 

  

  

Michael Sausen 

RV-10 #352 Working on  Fuselage 

Do Not Archive 

Recent RV-10 Build Activity

  



   From: owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jesse  Saint

Sent: Tuesday, April 25, 2006 1:33 PM

To:  rv10-list(at)matronics.com

Subject: RE: tunnel  heat

 

  

I have a hard time  believing that the scat tubes are causing the tunnel to get so hot.  There  is only heat going through them when the heater is on, and then the air is  flowing through into the cabin, so the cabin is also heating up.  Am I  missing something? 

  

I N256H we have not  noticed any excessive heat in the tunnel and it has flown over 200 hours.   We haven’t paid a lot of attention to it, but in that much airtime, I would  think the issue would show up.  We didn’t do anything special to insulate  it. 

   

Jesse  Saint 

I-TEC,  Inc. 

jesse(at)itecusa.org (jesse(at)itecusa.org) 

www.itecusa.org 

352-465-4545

    

 

From:  owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Tim  Dawson-Townsend

Sent: Tuesday,  April 25, 2006 9:29 AM

To:  rv10-list(at)matronics.com

Subject: RE: tunnel  heat

 

  

Michael, can you report  a source for your insulated SCAT? 

  

TDT 

40025 

     

 

From:  owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of RV Builder (Michael  Sausen)

Sent: Tuesday, April  25, 2006 10:09 AM

To:  rv10-list(at)matronics.com

Subject: RE: tunnel  heat

 

  

  This has been an ongoing problem, lot's of stuff  in the archives about it.  Not sure if anyone has really determined 100%  what the cause is but there has been lot's of speculation and remediation  techniques discussed.  Some of the possible problems are:



-Air  leakage through the heat boxes on the firewall

-Radiated heat via the  firewall

-Radiated heat from the exhaust/engine cooling

-radiated heat  from the SCAT tube running through the tunnel



  I believe Tim used  silicon baffle material as a thermal break when he attached the firewall cabin  heat vent boxes which is probably a good idea.  I used a ceramic paint  additive and painted the inside of the firewall, tunnel, and floor.  I also  sprayed my acoustic material in the same areas which may add some additional  insulating capacity (doubtful but anything helps).  I may also use the  standard firewall insulation but that stuff doesn't work very well unless you  can keep it completely air sealed against the firewall.  The last thing I  am going to try to avoid this problem is to use insulated duct instead of  regular SCAT.  The stuff is hard to find, and a lot more expensive, but  heat is a serious problem living in Texas (at  least to someone from Wisconsin ) and I really want to keep it  controlled.



Michael Sausen

RV-10 #352 Working on Fuselage

Do Not  Archive



--

jesse(at)itecusa.org
Guest

Posted: Tue Apr 25, 2006 11:42 am Post subject: tunnel heat

We actually used some RTV and wax paper to seal the vents.  When it is cured, the wax paper is removed and the RTV stays on one part that will seal against the other part.  It seems to have worked.  

     

Jesse Saint  

I-TEC, Inc.  

jesse(at)itecusa.org (jesse(at)itecusa.org)  

www.itecusa.org  

352-465-4545  

        

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of RV Builder (Michael Sausen)

 Sent: Tuesday, April 25, 2006 2:03 PM

 To: rv10-list(at)matronics.com

 Subject: RE: tunnel heat  

  

   

Jesse,  

   

  If the vent boxes are leaking heated air into the SCAT it will indeed radiate heat.  Sounds like you got lucky and have some tightly closing vent boxes.  Or maybe much in the same way Randy doesn't have much of a problem, you did something in the engine compartment to negate it.  Like others have said it is probably a combination of different things, but it is a problem and it does exist on others -10's as has been reported.     

   

  

Michael Sausen  

RV-10 #352 Working on Fuselage  

Do Not Archive  

Recent RV-10 Build Activity    

   

  

       

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jesse Saint

 Sent: Tuesday, April 25, 2006 1:33 PM

 To: rv10-list(at)matronics.com

 Subject: RE: tunnel heat  

I have a hard time believing that the scat tubes are causing the tunnel to get so hot.  There is only heat going through them when the heater is on, and then the air is flowing through into the cabin, so the cabin is also heating up.  Am I missing something?  

   

I N256H we have not noticed any excessive heat in the tunnel and it has flown over 200 hours.  We haven’t paid a lot of attention to it, but in that much airtime, I would think the issue would show up.  We didn’t do anything special to insulate it.  

     

Jesse Saint  

I-TEC, Inc.  

jesse(at)itecusa.org (jesse(at)itecusa.org)  

www.itecusa.org  

352-465-4545  

        

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Tim Dawson-Townsend

 Sent: Tuesday, April 25, 2006 9:29 AM

 To: rv10-list(at)matronics.com

 Subject: RE: tunnel heat  

  

   

Michael, can you report a source for your insulated SCAT?  

   

TDT  

40025  

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of RV Builder (Michael Sausen)

 Sent: Tuesday, April 25, 2006 10:09 AM

 To: rv10-list(at)matronics.com

 Subject: RE: tunnel heat  

  

   

  This has been an ongoing problem, lot's of stuff in the archives about it.  Not sure if anyone has really determined 100% what the cause is but there has been lot's of speculation and remediation techniques discussed.  Some of the possible problems are:

 

 -Air leakage through the heat boxes on the firewall

 -Radiated heat via the firewall

 -Radiated heat from the exhaust/engine cooling

 -radiated heat from the SCAT tube running through the tunnel

 

   I believe Tim used silicon baffle material as a thermal break when he attached the firewall cabin heat vent boxes which is probably a good idea.  I used a ceramic paint additive and painted the inside of the firewall, tunnel, and floor.  I also sprayed my acoustic material in the same areas which may add some additional insulating capacity (doubtful but anything helps).  I may also use the standard firewall insulation but that stuff doesn't work very well unless you can keep it completely air sealed against the firewall.  The last thing I am going to try to avoid this problem is to use insulated duct instead of regular SCAT.  The stuff is hard to find, and a lot more expensive, but heat is a serious problem living in Texas (at least to someone from Wisconsin ) and I really want to keep it controlled.

 

 Michael Sausen

 RV-10 #352 Working on Fuselage

 Do Not Archive

 

 --

dlm46007(at)cox.net
Guest

Posted: Tue Apr 25, 2006 1:01 pm Post subject: tunnel heat

thanks for all the replies; now for a real heart  breaker. Your tax dollars at work....

  

  

 http://www.spaceref.com/news/viewsr.html?pid=20396

  

 [quote]   ---

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