Dusts high altitude heating system

[mjgundry]

What would be the problems involved with changing the heat source from the plans heat muff to a heater core as Velocity and Mr. Wilhelmson have done, but leave the heater core in the back instead of plumbing it up to the nose? Seems to me this would be lighter and safer.

 

Matt

[John Slade]

No major problem with that, but here are the negatives:

 

- The weight is at the back. It's often better to have extra weight in the nose for weight & balance reasons.

 

- The heat is transferred via a long tortuous fiberglass air duct. Much of it is lost in the transmission.

[Wayne Hicks]

Why not use a recirculating system? There were plans for such a system in a CSA newsletter some time back. The builder used two oil coolers -- one with a vernatherm (to operate like a normal oil cooler) and one with the vernatherm removed (so oil flowed through that cooler all the time).

 

The builder built an input and output manifold over the cooler and ran the cabin duct work accordingly. I believe he used the standard plans heat ducting. He installed a marine bilge blower into the system, either blowing the air across the cooler or sucking the air through the cooler (I forget which one).

 

So instead of relying on highly heated air and huge airflows used once, this closed loop system just continually reheats its own air up the the maximum thermal output of the cooler. Since your fuselage is a foam filled thermos, you'll be toasty warm after 10 minutes. You more or less use the standard ducting, don't have to run an oil cooler and its lines into the cockpit, and you don't have to worry about how to dump out all that incoming air.

 

If you're interested, talk with Nick Ugolini. He explained this system to me one night. I believe Jack Wilhelmson is involved somehow too, but I can't swear to it.

 

....Wayne Hicks

[mplafleur]

I was wondering about a heat exchanger in the oil pan. (I don't know how much room is in the oil pan) The pan can have a coil of copper tubing inside with an inlet and an outlet at the side or bottom of the pan. The inlet and outlet can go to a radiator and you can circulate a glycol solution, or even oil if you're worried about a leak, through the system for heat transfer.

 

Just "off the top of my head brainstorming".

[marbleturtle]

I REALLY like the idea of a water heating system seperate from the engine cooling system. I'm not worried about leaks from the system, but moving the engines coolant from back to front and back introduces possible problems with air pockets or pump failures. With a seperate system, if there is a failure in the cabin heating system, its no longer engine critical. But the benefit of heat transfer is still there.

 

Thanks Wayne!

[Jim Sower]

My Velocity has an oil cooler in the nose and tries to bleed/redirect exhaust from it to the cabin. It doesn't work well for a variety of reasons - mostly design defects. I'm with Wayne on this one - use a smaller capacity heat source and recirculate the air - except that I feel very strongly that it should be a low-pressure system. Oil lends itself nicely, but I don't like the idea of introducing high pressure oil and the attendant failure modes to the cabin heat system.

 

An idea that just came to me: Since the oil pump bypasses most of the oil back to the pan at operating rpm, why not put a "T" in the oil line to/from your cooler, followed by a small (1/8" max) orifice that would feed oil into the 1/4" or greater ID plumbing to your cockpit heat exchanger - perhaps located in the hell hole, or perhaps in the nose - and thence back to the pan. Small heater core, recirculating air, low pressure system. The orifice into the heating system could be calibrated to provide juuuust enough oil to do the job and not bypass oil that was needed for lubrication.

[Jim Sower]

In my haste I missed mplafleur's idea of a heat exchanger in the oil pan. That's a great idea. Answers all of my concerns: Oil heat (source), low pressure system. Recirculating oil (water occurred to me first, but if a line breaks in the pan ....) through several feet of tubing snaking through the bottom of the oil pan would be the perfectly benign heat source. Bring the lines out toward the top of the pan so a leak at the entrance/exit wouldn't be a serious problem, operate it with electric pump and blower and you're there. The worst (and arguably the least likely) thing that could happen would be a leak or failure where the plumbing enters/exits the pan, and you could put that high enough to be a fairly benign failure. You'd have to fasten the tubing to the pan pretty good to prevent fatigue, but that's certainly not rocket science. Might think of much lower viscosity oil for heat exchange and ease of pumping considerations.

Great headwork!!

[chuckthedog]

I just plug in my wind breaker (socks plug into it), and start turning the heat down about the time I reach altitude. I stay quite cozy. HE HE! When I land All I have to do is, unplug, remove head set, and kneepad with the Gps on it. Now what could be simpleier, and safer? PS Cheap and light too! PSS it is fused for 10 amps, it has never poped. I also use the plug for my tickle charger in the hanger,

[dust]

I am willing to bet that your solution is the right one, that won't stop me from trying a little, but i WILL not forget your advice.

 

In fact i was going to make a comment on that point, your works and is simple and effecient, hard to beat, but i'll give it a little try

 

enjoy the build/ or in your case, the fly

 

Mike

[macleodm3]

I may have mentioned this before, but my old '87 VW Scirocco 16V had a simple oil cooler that would work for airplane heat (not necessarily as the main oil cooler). The oil cooler screwed onto the block just as if it was itself an oil filter. The oil filter threaded directly onto the oil cooler. It was approximately 3" x 3" by 1.5" thick. It had two nipples for the coolant flow. Sold the car with 175k miles and the oil cooler had never failed. If it did fail, water would be introduced to the oil. Simple, but not as safe as routing an oil line through the oil pan... I like that idea! My Passat has a similar oil cooler, but has an oil hose running to it instead of the filter screwing onto it.

[LargePrime]

The plans system uses a duct from the firewall to the front of the instrument pannel to flow air to your feet. You can see it on many web sites. This duct has another purpose, it stiffens the "tub" as well.

 

I beleve the lightest fluid to use is air. A standard automotive blower, mounted at the firewall, that blew air over the muf, down the tube and over your feet and then took that same air and did it again would prove as effective as any I would guess.

 

But I dont think you can beat electric undies under your clothes.

[chuckthedog]

I bought my bird a Hot grip for Christmas. This is an after market item for snow machines. I only had to instal my PTT in the top, but had to put a reostat on the power to it. It realy keeps your hand WARM. When flying I like to keep my hand on the stick, and it would get cold. Not so now. PS: cost $30.oo bucks, but you get two.

[LargePrime]

Chuck can you tell us about the flying you do? How cold, high and whatever else you would like?

[Joe Patterson]

Exactly how high can an aircraft such as a Cozy go????

 

Let us say it has a turbo an CS prop.

 

I would like, every once in awhile, to go to the top.

 

It has been below "0" degrees at night here every night for a week, and it is that way during our "Rocky Mountain Winters".

 

Exactly how high can an aircraft such as a Cozy go????

[dust]

As high as you want to turbo it to go, well ok not 60,000 feet, but 25000 is a common altitude for piston engines, i imagine 30,000 would be easily doable in mine as i am sizing the turbo's for 100% power at 25000 feet

 

time to climb vrs duration of flight are probably the delimiting factors, also gas freezes at -64 and it was -60 when jim set the altitude record at 34000, normally aspirated in a long.

 

enjoy the build

 

dust

[chuckthedog]

large prime: I use to fly and live in Northern Michigan where summer is two months of bad sleding. You don't have to fly vary high to get cold on overcast days. most x country flights 5k to 11K depending on weather. Now that I live in tropical Indianapolis, you can fly from April till October and don't need even a coat. Most of my flying down here has been local with the exception of my monthly winter flights to the gulf. (winds and weathe permitting) The hot Longs are faster than mine cause I don't like to turn the engine at 75% or 2600RPM at 8K ASL fuel burn 11 GPR 175 MPH

I like 2350RPM 6.2GPH 152MPH. No wait. It will fly 200! Ya thats it. Thats the ticket. It could go faster with wheel pants, but I had a Luscombe ground loop, and almost flip over because of them. A friend of mine with a RV 6A Tricycle gear wore out a brand new Good Year, cause a chunk of runway black top got wedged in one.I also have never had any brake over heating problems. Hope this helps.

[LargePrime]

I was hoping you would talk about flying in the cold with an EZ.

 

Is the plans heat system that bad? How did you current electric clothing evolve?

 

A lessons learned alon the way kinda thing.

 

Unless you hit on the perfect system right off...

[chuckthedog]

The plans heating system is made for southern Ca. no Ox. If you put your finger in the duct you can feel warmth. It seem the positive pressure in the cockpit cansels out almost all the heat pressure. To keep the canopy clear you need to vent cold air in the cabin. I tried electric defrost heater. Too little heat for canopy, and with humid air make condensation. I tried a snow mobile suit. Too bulky, and you still get cold. heavy felt pack boots don't work. they make your feet so big you hardly can fit your feet through the panel cut outs, and can't tell if your feet are on the rudder peddels. I then tried disposable heat packs. better but a lot of draw backs. A friend who owns a motorcycle shop let me try his electric vest. Better. He showed me the catalog from Gerbings. I bought the wind breaker and socks. They worked. I removed the Rutan heat system. the plane lost 2 1/2 pounds The coat and socks plus the controler weigh in at 2 pounds. Your right hand is free to work the gas, knobs, and stuff, and put between your legs to keep it warm. Your left is always on the stick. the new hot grip cures that cold spot. With the socks I can fly with my deck shoes. I like this cause you can feel the rudder, brakes, and still strech out beside them when up and flying. Discounting weather. If you fly over 8K feet your out of the spam cans and below the heavy iron. Lots of open air. Rutan pointed out. To keep this plane fun keep it light and simple. Looking back I feel he is right. Before the electrical, lights, starter, more insturments. It was work, but fun. Don't get me wrong. The EZ Nose lift, starter, electric trim, and belly board are IMHO must haves. The lights, transponder,encoder, Gyros, etc, etc. are cool, but do take away from the performance. Hope this provides some insight. Now get to work, and fill the sky with fiber glass.

[No4]

"I bought my bird a Hot grip for Christmas."

Why didn't you just buy her a pair of gloves and tell her to stop complaining? I'd have kept the hot grip for myself.

 

Thanks for the advice Chuck, I'll be getting myself a nice pair of electric heated undies and all the rest of it.

Brilliant idea.

Cheers

Adam

 

PS in case it gets lost in the translation, bird = female of the species where I come from

[chuckthedog]

The knobs are small, and I gotta take them off to pick my nose.

[Steve Davies]

Woolen socks and sweater for me... simple, lightweight and removable if it gets too warm. Papa always said, "You can always take it off, but if you don't have it you can't put it on."

 

Sometimes I like old-fashioned solutions. If its too cold, get outta the icebox. lol.

 

Of course I really have to wait til I get to 15,000 feet and see for myself, but to me, KISS priciple is best.

[chuckthedog]

Tell me more about this Missouri Wool. The stuff I tried didn't cut the mustard.

[LargePrime]

One word. Warsaw

[Steve Davies]

Well fellas, I haven't got any high altitude experience, just spewin' what I thought mighta been cheapest alternative to lotsa extra weight and complication... My ecducation continues, and I'll cross that bridge when I get to it. I've recently learned that heat muffs can hide/cause exhaust cracks -- not very appealing to me. Oil cooler alternative seems excessively heavy and possible oil leak into cockpit is even less appealing. The hair dryer is right out. A wood stove is also out the window. I havent got a solution, but of what i know so far, it seems that the heat muff is best so far... Just have to keep up on inspections. Thumb heaters on snowmobiles work the same way, so I gues thats the simplest and lightest, even witht the danger of the exhuast cracks. ( hi to my buddies up in Timmins, ON)

[dust]

As far as i know, the heat muff, if clamped on is fine, the welded on om had a problem

 

enjou the build

 

Dust