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Back seat air

T

thilokind

Active Member
Hi folks,

maybe somebody can point me in the right direction... I can't find that information in the plans... How am I supossed to get air (hot / cold) to the back seat in the RV 8a? There is an air vent near the control stick, but I can't work out the routing of the hose from the front.

Thanks
 
There is no heat to the back seat of the -8. Some install a heated
rear seat. Fresh air comes from a inlet under the right wing and the
ducting comes into the fuselage with a vent next to the rear control
stick.
 
thilokind said:
There is an air vent near the control stick, but I can't work out the routing of the hose from the front.
Click to expand...

The rear seat air vent is fed by a duct hose that routes under the floor, out the right side of the fuselage and into a NACA scoop inlet on the bottom side of the right hand wing. This is all part of the standard Vans design.

Getting heated air plumbed to the rear cockpit of an RV-8 is another story. Achieving that is left up to the imagination and ingenuity of the builder, and if anyone ever conjures up a really good and effective way to do that, they'll become a hero to lots of RV-8 owners!
 
Neal@F14 said:
The rear seat air vent is fed by a duct hose that routes under the floor, out the right side of the fuselage and into a NACA scoop inlet on the bottom side of the right hand wing. This is all part of the standard Vans design.

Getting heated air plumbed to the rear cockpit of an RV-8 is another story. Achieving that is left up to the imagination and ingenuity of the builder, and if anyone ever conjures up a really good and effective way to do that, they'll become a hero to lots of RV-8 owners!
Click to expand...

Heck! I would be happy to get any kind of heat up front too!!!

I choked mine down to a 1.5inch hose and it barely came up in temp.
 
Heat

Heated seats and Gerbings electric jackets , the jacket is a light insulated wind breaker with heating element wire designed for motorcycles , works in my open cockpit biplane too.
 
SmilingJack said:
Heck! I would be happy to get any kind of heat up front too!!!
Click to expand...

The fire-breathing ECI IO-360 Titan engine with 9.2 compression pistons in my buddy's RV-8 that I helped build, actually makes pretty good heat for the front seat as long as you keep the power and mixture setting where the engine is producing plenty of heat out the exhaust pipes. It's got a Vetterman 4-pipe exhaust system and a cabin heat muff that clamps around two pipes at once.

None of the cabin heat ever really makes it to the back seat though, but the front seat stayed comfortable even when OAT was in the 20's at the surface and much colder at cruising altitude when I flew it across Texas one cold clear winter day.
 
I have a TMX0360 with heated seats and Vetterman exhausts with mufflers. The mufflers, which have an outer heat shroud, put out a generous amount of heat.

i have two heater exchange valves, one plumbed to the middle of the firewall and one plumbed to a vent that is on the aft side of the front baggage area, adjacent to the gear leg. This will shoot the hot air down the right hand side.

With a tightly sealed canopy skirt, both my pax and I can fly in the New England winter without jackets.
 
drill_and_buck said:
I have a TMX0360 with heated seats and Vetterman exhausts with mufflers. The mufflers, which have an outer heat shroud, put out a generous amount of heat.
Click to expand...

Mufflers capture so much more heat from the exhaust than just the simple cabin heat shroud around the plain pipes. My poor little RV-6 only has a shroud clamped around a single pipe and it is far from effective at picking up much heat.
 
stainless steel "chore boy", scavenge holes

Put a couple of stainless steel "chore boy" scrubbers inside your cabin heat muff.

There is plenty of heat in the exhaust, the problem is the heat transfer off of the pipe and into the air that is flowing through the heat muff. I have a 1" restriction hole on the fresh-air inlet that feeds the heat muff. I get plenty of heat in my RV-8, and I have it set up to shoot down the left side past me into the back seat. I don't get any complaints from the back, except for the draft on her neck. She wears a scarf, and there is seat-heat too.

Also, the stock kit doesn't have enough provision for air to exit-- you can't expect flow to come in if you don't give it a way to get out. Search for my posts on the scavenge holes that suck air from the rear canopy area and pull it into the tail cone behind the baggage bulkhead. I have not gotten around to making the exit flow nozzle for the tail cone to improve cabin airflow even more.
Maybe this winter.
 
scsmith said:
Put a couple of stainless steel "chore boy" scrubbers inside your cabin heat muff.

There is plenty of heat in the exhaust, the problem is the heat transfer off of the pipe and into the air that is flowing through the heat muff. I have a 1" restriction hole on the fresh-air inlet that feeds the heat muff. I get plenty of heat in my RV-8, and I have it set up to shoot down the left side past me into the back seat. I don't get any complaints from the back, except for the draft on her neck. She wears a scarf, and there is seat-heat too.
Click to expand...

I'm also thinking of wrapping my exhaust pipe under the heat muff with a large diameter spring to try to help increase the surface area where the heat can leave the exhaust pipe, but am a bit worried that there might be enough vibration to cause the pipe to wear thru under where the spring contacts the pipe.

Any thoughts on that idea?

I read about this on another thread here in the VAF forums. The idea has some merit as to increasing the amount of hot metal that could transfer heat to the air flowing thru the muff, but I'm curious if anyone here has actually tried it.
 
The first thing I did was put electric heated seats in when I bought mine in October 2 years ago! My 8A has no side panels and was still a little chilly in the rear yet! So I put a Y off the firewall where the heat comes out of and fitted 1" scat hose in it. The scat runs on left side and under the throttle quadrant and angled down between legs of rear passenger!

It is exposed but works well, in spring I just pull it off and reinstall in the fall! I did restrict the front about half and is plenty for front.
 
The search function is your friend.
Search, advanced search, rear heat, titles only, search now

Many threads, pictures, examples of what others have done.
 
Some feedback on my RV8 rear duct

You may find my rear ducting thread after you search....but now that the aircraft is flying (in -15 to -20C) I have some feedback from my rear seater.( http://www.vansairforce.com/community/showthread.php?t=55773 )

I ran a duct under the right hand sill that directs heat at the rear seater with the outlet just aft of the roll bar. Actually, I had more complaints during the summer that some hot air was managing to blow back if the butterfly valve wasn't completely closed. As others have mentioned, seal that canopy skirt as best you can. Making an opening for outlet air is important too.

A rear duct does require a bit of preplanning though.
1: You need to go for a 4 pipe exhaust so you can put in two heat muffs...this of course leads to two heat boxes on the firewall with the associated scat tubes. (This is for a fwd inlet IO360...there are other engine configs that you can get a muffler on, so you would have other options...)
2: Make sure your sight-line to your breakers aren't obstructed by the duct. My duct just fits this criteria. I have been 'annoyed' by its presence a few times, but the trade off is worth it for a happier G.I.B.
3: I ran the scat through my fwd baggage compartment at the corner. It hasn't been a problem with the baggage space there, since I fill the lower area with my tie down bag, my toolset, and a spare quart of oil.
3: You need to run another heat control to the rear seat (that you can also reach from the front seat...I put mine just aft of the roll bar below the duct outlet.
 
Stainless mesh

I have seen course stainless steel mesh used in the heater muff to good effect. It is commonly used in restaurants to scrub pots. You can experiment with how much you want to use. The main purpose is to slow the air down a bit allowing it to gather more heat from the muff as well as provide more surface area for heat transfer. You will not have to worry about it eating into your expensive exhaust like a spring might. Your concern with the spring is valid.
 
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