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RV-8 Rear Seat Heat

M

Mike McNamara

I'm New Here
I'm considering building a RV8.

I've heard that getting heat to the rear seat is difficult. My wife wouldn't like being cold. I may not go with an RV8 if it will be cold back there.

Any good suggestions for back seat heat?
 
Me too!

Most folks will say heated seats but they scare me - fire! I don't like the idea of stepping on that electro heat mat sewn into the seat bottom, that's just me. Mike Stewart's Super8 runs scat through the spare web where the control column goes through and it seems to work for him. Another fellow built a plenum/duct arrangement that goes along the right side of the cockpit- not bad, bit too much work and takes up too much room.
Do a search to see all these with pics. Still not sure if or what I plan to do.
 
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wife loves the seat heat, heater flow OK

Hi,

First, welcom to the VAF forum! The -8 is a marvelous airplane. My wife probably on balance still wishes I built a -7, but she enjoys the roominess in back too.

I spent quite a while thinking about ways to duct some heat to the rear. Unfortunately, mine was a QB (quickbuild), so much of the fwd fuselage was already built.

If I could do it over, I would run a 1.5" scat from the firewall area back through the left gear tower, rather low, and then up under the front seat ramp, through a Tee, then out the ends of the seat ramp wedges, to elbows. These elbow fittings would blow heat right on the back-seater's feet. Nice!

What I DID do was install seat heat in the back, with the Classic Aero Designs 'aviator' seats.

My wife LOVES it. We've had Volvo's with seat heat for years, and lots of people use it. Do you really think it's much of a hazard?

We also find that the cabin heat air flows back pretty well to the rear, perhaps because of my scavange vents in the aft canopy area.
 
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One solution

Mike Stewart cut a hole in his spar web. The wing still in one piece despite Mike's efforts to break it.

Here's the LINK.
 
Welcome!

Welcome to VAF, cousin! Always nice to see a familiar name online. :D

I had the pleasure of flying my -8 all last winter while in Phase I. I have heated seats and a single heat muff, with the SCAT tube exiting the right gear leg tower. My observations:

1) For those of us who fly in winter up north, a single heat muff doesn't do much when it gets below freezing. My right leg heats up, but that's about it. When I completed Phase I, it wasn't that cold anymore, and my wife didn't have an opportunity to chime in on the effectiveness of the heat making its way to the rear.

My plan was to either add another muff in series or try making some baffles for the existing muff to increase the surface area in the muff. Haven't gotten around to doing either yet.

2) Heated seats. 'Nuff said.

3) Aileron boots. Do a search here and you'll see what they are, how they are made and how they work. They limit the air sneaking in through the aileron push rod holes and up through the floor.

4) Door snake. Haven't done this one yet, but I think it's a simple solution for the air the seems to always blow in from the rear of the canopy in flight. I think having the passenger stuff one of those gizmos on the turtle deck would stop most of the flow of air.

Maybe running SCAT tubing back to the rear is worth it, but I can't help but feel that the air would cool significantly before it exited, leaving nothing but lukewarm air blowing in the rear, but I could be wrong.

Hope that helps, Mike. And again, welcome to VAF!
 
N8RV said:
Maybe running SCAT tubing back to the rear is worth it, but I can't help but feel that the air would cool significantly before it exited, leaving nothing but lukewarm air blowing in the rear, but I could be wrong.
Click to expand...

Yes you are wrong about that.
 
First Post...be nice...

I have read many posts on heat and suggestion on what to do. The one I just tried was putting a bunch of "SS Scubbies" in my heat muff.

This morning I went up for a test flight and froze my butt off! It was 10F outside and when I use my handy dandy IR temp sensor inside it was only 25F with 35-40F at best coming from the heat outlet.

Does anyone have any suggestions or comments on what to expect on these very cold days?

John
 
Little electric heaters?

Anyone know if a very small electric 12v heater blowing on the GIB's legs would work? If my math is right, a 50 amp alternator should have enough extra power to put 250 or so watts back there, assuming a "normal" panel and pmags.
 
Mike McNamara said:
I'm considering building a RV8.

I've heard that getting heat to the rear seat is difficult. My wife wouldn't like being cold. I may not go with an RV8 if it will be cold back there.

Any good suggestions for back seat heat?
Click to expand...

I can't imagine that the heated seat would adequately compensate for the frigid breeze coming in around the back and sides of the canopy. If you really want an -8, I suggest you folks do what Paul and I do. If he insist on taking the Valkyrie (-8) when it's really cold, he gets the backseat and I get to fly in the front. Seems fair to me! ;)
 
not so much draft with scavange ports

Hi Louise, I love your new avatar.

I have two 1" holes in the turtledeck just behind the baggage bulkhead, under the canopy skirt. This scavanges a lot of the draft into the tail cone. I posted a picture some time ago.

My wife reports a very mild draft coming in, and she wears a scarf (looks very dashing!). The scavange holes seem to help the heated air travel to the back seat area since the cabin air has a place to escape, it lets more air in.

I think I need to increase the flow more by creating a larger area for the tailcone air to exit. As it is now, it goes out through the elevator horn area and out through the rudder cable exit holes. I'm thinking about putting a proper vent somewhere, but I don't want to let mice in.

She says she is very comfortable with the heat on and the seat heaters on, and the neck scarf.

Now, the caveat here is, you all can tease us about what cold is, because we're from California. I'm talking about flying over the Sierras in the fall where the OAT was maybe as cold as 20F, probably more like 25F.
So, eventually, I'll get her impressions when it is actually cold(er)....
 
Rear seat heat

There was a good article in the RVator about lining lower canopy skirt edge with a felt strip or similar. Effect was to warm rear seat area a lot and also decreased noise from canopy skirt vibrating vs. fuselage. Using boots around aileron and flap pushrods helps as well. Problems are probably not insurmountable.
 
Bill Dicus said:
There was a good article in the RVator about lining lower canopy skirt edge with a felt strip or similar. Effect was to warm rear seat area a lot and also decreased noise from canopy skirt vibrating vs. fuselage. Using boots around aileron and flap pushrods helps as well. Problems are probably not insurmountable.
Click to expand...

The felt around the edge of the canopy skirt is THE answer to the vibration and buzz - but sorry, it doesn't stop the airflow problem (in my experience). The airflow is not a tornado, it's a nice little leak - which really gets old after 3+ hours at 12,000', which is where the RV-8 really shines as a cross-country machine!

I still think the RV-8 is the all-around champion of the two-placers - but from a passenger temperature standpoint (only), Louise is right - the side-by-sides are better. Of course, if we're talking shoulder room.....:rolleyes:

Paul
 
another way

I decided to make whole side panels for the rv-8 interior and in the process I extended the arm rests back to a point that scat tubing could be run to the rear of the aircraft through the arm rest. My RV isn't flying yet so this design is theoretical, but is progressing nicely. Sorry for the quality of the pics, took them with my Iphone.
2lcagev.jpg

6g8nqa.jpg

14qquq.jpg

2exasgi.jpg
 
flyboykelly said:
I decided to make whole side panels for the rv-8 interior and in the process I extended the arm rests back to a point that scat tubing could be run to the rear of the aircraft through the arm rest. My RV isn't flying yet so this design is theoretical, but is progressing nicely. Sorry for the quality of the pics, took them with my Iphone.

... photos snipped for brevity ...
Click to expand...

Thanks much!

:)

You have an idea that I just might steal when the time comes for me to work on the fueslage.
 
Ironflight said:
The felt around the edge of the canopy skirt is THE answer to the vibration and buzz - but sorry, it doesn't stop the airflow problem (in my experience). The airflow is not a tornado, it's a nice little leak - which really gets old after 3+ hours at 12,000', which is where the RV-8 really shines as a cross-country machine!

I still think the RV-8 is the all-around champion of the two-placers - but from a passenger temperature standpoint (only), Louise is right - the side-by-sides are better. Of course, if we're talking shoulder room.....:rolleyes:

Paul
Click to expand...
Sorry to hear that Paul! If I ever get flying will solve that problem somehow. It's a must for joint travel and keeping a happy union!
 
Thanks! My Christmas present from Paul

scsmith said:
Hi Louise, I love your new avatar.
Click to expand...

Paul commissioned a painting from the same friend who painted his portrait next to the Valkyrie (http://www.zahradka-art.com/portfolio.php?art=111) a few years ago. Flying is Paul's first life-long passion and cave exploration (particularly in Mexico) has been mine. Hence, our portraits show us preparing to embark on our respective adventures. An engine and an oil portrait for Christmas this year. Paul is definately a keeper! :D

Here's the full portrait, for anyone interested: http://www.zahradka-art.com/portfolio.php?art=139 Gary was fabulous to work with and it's a gift I won't forget!
 
flickroll said:
I bought this stuff in the Aviation section of Lowes:

http://www.lowes.com/pd_127945-81-6...&currentURL=/pl__0__s?Ntt=weatherstrip&page=1

I split it in two (lengthwise), leaving two long strips. I played around with placement of the weatherstrip, and have eliminated about 90% of the air that comes in from the back. My wife is happy :D
Click to expand...


LOL! Great minds think a like, Jim. I did the same thing. I had felt on there, but it was removed when Smokey was painted. When it came time to replace it, I thought I'd give that stuff a try and it works great. Still a lot air sneaks in from back there though.
 
"What I DID do was install seat heat in the back, with the Classic Aero Designs 'aviator' seats.

My wife LOVES it. We've had Volvo's with seat heat for years, and lots of people use it. Do you really think it's much of a hazard?"

How many amps at 12V does the seat heater use?
 
N8RV said:
LOL! Great minds think a like, Jim. I did the same thing. I had felt on there, but it was removed when Smokey was painted. When it came time to replace it, I thought I'd give that stuff a try and it works great. Still a lot air sneaks in from back there though.
Click to expand...

Gotta keep Mamma happy. If she ain't happy, NOBODY's happy!
 
I'll check this weekend and report back

Hi Mike,

I'll check the current draw on the seat heaters when I'm out there this weekend, and will post here.

Mike McNamara said:
"What I DID do was install seat heat in the back, with the Classic Aero Designs 'aviator' seats.

My wife LOVES it. We've had Volvo's with seat heat for years, and lots of people use it. Do you really think it's much of a hazard?"

How many amps at 12V does the seat heater use?
Click to expand...
 
My seat heaters only draw about 2 amps each seat.
They do work well and keep my back and butt nicely warm even in -7C temps.
 
RV-8A Rear Seat Heat

RV-8A Rear Seat Heat

Since it?s winter, and although I?m not flying yet, here?s my contribution to the RV-8/8A rear seat heat ideas:















Spar Tubes:

1.25-inch flanges (ACS P/N 10350-5)
1.125-inch OD Tube, .049 Wall (ACS P/N 03-36980)
.040 2024T3 Donut Rings (approx. 2.5-inch OD to match flange OD and 1.125-inch ID to match tube OD) (installed between each flange and the spar web)
3M 2216 Structural Adhesive

Aluminum ?Y? Connector (not shown): One 2-inch SCAT to Two 1.25-inch SCAT Tubes

Two 1.25-inch SCAT tubes run from the Rear Spar Face, routed above the floor (to miss the roll servo and trim system), and under a 1.5-inch-depth pilot seat base to just in front of the rear stick. (Note: the two 1.25-inch SCAT tubes have only half the area of one 2-inch SCAT tube. I?m planning to install a 2-inch fan box aft of the pilot?s seat to pull hot air from the 1.25-inch SCAT tubes.)

The rear seat heat source is a dedicated 2-inch heater valve on the firewall. This heater valve is controlled by a cable running from the left rear cockpit wall to the valve. A second, separate heater valve supplies the front cockpit.

Overall system weight (heater valve, cable, SCAT tubing, ?Y? connector, spar tubes, pilot seat base) is approximately +4.5 pounds (2.5 pounds of this is the pilot seat base).

What I would probably do differently next time: For the spar tubes: Use 1.5-inch flanges and 1.375-inch OD tube. Reduce the OD of the 1.5-inch flange to the approx. 2.5-inch OD of the 1.25-inch flanges. Also, the ?flyboykelly? approach (side arm rest consoles) looks promising as an alternative to the spar tubes.

NOTE: I?m planning to use felt to help seal the rear canopy skirt area and reduce vibration (Thanks to Paul and others for this tip). Also, I?ve installed a fiberglass cap over the rear canopy bow, sealed with a ?d? seal on top of the turtle deck just aft of the copilot?s seat (Thanks to a red RV-8 at Oshkosh). Also, I?m planning to add two scavenge holes (Thanks Steve Smith) in an attempt to vent the higher pressure rear canopy skirt flow into the lower pressure tail cone.

This approach is ?Food For Thought,? anyway. Next winter, I hope to report how well, or not well, it works!

Good Luck!

Bill Palmer :)
 
I'm going with the GERBINGS electric clothing; Jacket liner & gloves. They work well on my bike, and they are light & simple.
12VDC outlets on the left side, along with the headset cords and oxygen hoses. The idea is to keep them together and neat, aft and below the throttle.
12Vdc accessory power for GPS or laptop etc comes from the right side.
The idea is to keep them apart from the stuff connected to the pilot / passenger, and the 12V switch panel is already on the right side, so the wire runs will be short.
I hope that makes sense.
 
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