AeroVee cabin heat

[mike.smith]

I am currently building my cabin heat components. I decided to try 1.5" SCAT because I have heard 2" can push too much air through. I also baffled the output hole of the heat muff. I will be packing the muff (altered the muff plans I found on the Sonextalk site) with stainless steel choreboy type scrubbers, as I have seemed to read other places that those seem to radiate the heat better than the spring. I guess we will see. Once we get out of the negative temps (-35f with wind chill) I will head back out to work on it.

Another good idea :-) I'm making this muff removable for inspection, but that will also allow me to try other materials inside. Even when you're "done" building, you're never "done."

[vigilant104]

FWIW, the best thing about Bryan's sketched out idea is that the fin area can pick up a lot of heat from the pipe. Wire springs and SS steel wool will touch the pipe only in a few spots/small total area. The key to getting the heat into the cabin air is to remove as much as possible from the wall of the exhaust pipe.

An easier fabrication of Bryan's concept (no rivets) would be to accordion fold some thin SS, (maybe 3/4" high folds?) spread it out a little, then wrap it around the exhaust pipe and secure the outside diameter with a few hose clamps or springs. The SS will contact the exhaust pipe in long lines, giving a lot more area to remove the heat from the exhaust pipe wall. Paint the SS accordion flat black on exhaust pipe side to do the best job of grabbing the radiant heat from the pipe, too (rather than reflecting it back to the pipe).

Baffling the outlet hole: If the goal is to slow the airflow through the heat muff (so it gets warmer due to longer contact time), it will be more effective to slow it down with SS scrub pad material, additional cross-oriented fins, etc that will also help to transfer the heat from the pipe to the air as well as slowing it down. BTW, slowing the air down will >not< allow it to carry away more heat from the exhaust pipe--it will carry away less total heat than if the air was whipping through. But it will be warmer air when it finally gets into the cabin (just less of it).

Keeping at least some outside air flowing through the heat muff when the heater is "off" seems to be a key to making it last longer. And a robust SS (not AL) control box on the firewall is important to keeping the fire on the correct side of the firewall if things ever turn "hot".

Just my two cents. I haven't built my own heater yet.

[MichaelFarley56]

Mark -

Are you still considering cabin heat? Please let me know if you decide to add something; I'd be happy to assist!

[planeolbob]

Believe me, you don't need it. I had it and took it out. A waste of time and weight. Oh, it worked fine but all you need to do is go to Walmart Aviation Supply and buy some ski bibs.

Bob (Bibs) Mika

[gammaxy]

Believe me, you don't need it. I had it and took it out. A waste of time and weight.

I'm hesitant to comment on this since I fly in Alabama. I have flown a lot the last couple months in with OATs around 10-30F and haven't felt like I need cabin heat. I recently flew four hours with my 4 year old son in temperatures around 20-30F and he said he wasn't cold. We both wore two layers of pants and shirts with jackets and were fine once the canopy closed and started getting the greenhouse-effect. In cruise flight, I think I felt some heat coming off the firewall, but not sure.

I recently sealed the gap between the canopy and turtledeck. I haven't yet sealed the wing-fuselage gap, but I think that will get rid of most of the draft I have left and make it even more comfortable. Personally, I think I'd be fine around 0F for a couple hours at least.

One thing I haven't done yet is installed the upholstery on the sides of the fuselage. Leaning up against the bare aluminum can get pretty cold. That only happens when there's two big people inside though :-)

[Onex107]

I made a muff for the right side that is square/retangular and it incorporates the "Y" joint where the most heat is. The square muff fits next to the case nicely and I think it has more volume than a round one. It's aluminum and baffled inside to direct the air up and down, not unlike a muffler. I made some alum strip and clipped the edge so when it's wrapped a round the pipe it puts "hair" on it. A couple of hose clamps holds the ends. Aluminum melts at 1100 F. and I'm not concerned about it failing. I'm sure over time it will break down. But thats another muff, better designed, with maybe a different material. Makein it as a box, all the bends can be made on a simple break and the end caps are screwed on. The joints are caulked with RTV and are holding up well.

[jerryhain]

Can we get pics?

[vigilant104]

Mark -

Are you still considering cabin heat? Please let me know if you decide to add something; I'd be happy to assist!

Mike,
I'm still thinking about it--but it's just not much fun working in the hangar at the current temps. First, I need to finish/install the rear fuselage blockoff you made (thanks!), as reducing the drafts from the tailcone will help a lot (and if I still need a heater after that, it will give it a fighting chance).

Lesson re-learned for me: Either heat the hangar or get the deferred MX/projects done before winter arrives.

Mark