How warm is a canard?

[LargePrime]

I would think that a canard is warmer than a typical spam can.

 

But it seems that there are lots of suggestions on how to heat our canards.

 

So are they colder than your typical spam can? If so why?

[Marc Zeitlin]

Originally posted by LargePrime

I would think that a canard is warmer than a typical spam can.

When the sun is out, you bet. Other than than, it's about the same.

 

So are they colder than your typical spam can? If so why?

They're colder in some cases (with the stock heating system) for a couple of reasons. They tend to leak more than the typical spam-can that's well maintained (although I've certainly flown in a few 172s/warriors that were made of swiss cheese from an air infiltration standpoint), plus the heating system is a lot further away from the heat point. It's about 2 - 3 feet from the heat muff in a 172 to the heat outlets, and about 8 - 10 feet in a canard. More flow resistance, less flow, more heat dissapation within the duct rather than into the cabin.

 

You've got to remember that the V.E./L.E./COZY families were designed by guys that live in the freaking desert and only fly north in the summer :-).

[dust]

since when is minnesota the desert??

[Marc Zeitlin]

Originally posted by dust

since when is minnesota the desert??

Tell me where Mojave is, and who designed the heating system in the V.E./L.E. that Nat leveraged. Then tell me when Nat moved to Arizona, and/or how much he modified the original heating system (from the standpoint of moving large quantities of hot air from the back to the front).

[LargePrime]

It would seem a composite over foam core duct would lose much less heat than any other standard duct material.

 

Air restiance due to distance would be a big issue.

 

I havent found any recomended way to upgrade the stock system. In fact, I see everyone running wires in the heat duct. That was one thing that made me think the cozys must be plenty warm.

 

Leaking should be only around the front gear and the canard holes right? (not counting vents). The offset canard controlls dust showed me should elimanate the canard leak. I would guess dust and cliffords front gear cover should mostly eliminate that leak. With these leaks plugged would the stock system be adequate?

 

Does Nat or the Cozy Community have a recomended procedure for increasing the heat output for high/northern fliers?

[Marc Zeitlin]

Originally posted by LargePrime

It would seem a composite over foam core duct would lose much less heat than any other standard duct material.

Maybe, but the duct length/surface area is MUCH larger.

 

I havent found any recomended way to upgrade the stock system.

There are MANY ways. Electrical heaters, oil heaters, blowers in the stock air duct, etc. See the COZY mailing list archives. See the CSA newsletters.

 

Leaking should be only around the front gear and the canard holes right? (not counting vents).

 

Should be, but there are many other leak points. The landing brake actuator hole, for instance. The canopy seal, for another. There are ways to seal these, but none are in the stock plans.

 

The offset canard controlls dust showed me should elimanate the canard leak.

 

The offset in the canard torque tube helps, but it hardly seals the hole. There are a number of ways of sealing the 1/16" space that you BETTER have around the torque tube, but again, none are in the stock plans.

 

I would guess dust and cliffords front gear cover should mostly eliminate that leak. With these leaks plugged would the stock system be adequate?

IF you plugged ALL the holes, and sealed the canopy well, as well as ensuring that the stock heating system was working at full efficiency, I'd estimate that you'd be able to keep the cabin at 35F to 40F above ambient temperature on a cloudy day. Right now, I'm getting 25F above ambient in my COZY MKIV, and I've still got lots of work to do to seal holes. This is perfectly reasonable down to 25F or so (ambient temp), but in the winter up high, it gets a LOT colder than that, even with a lot of clothing on.

 

Carl Denk swears he flies all year in his Classic in his shirtsleeves, so it should be possible.

 

Does Nat or the Cozy Community have a recomended procedure for increasing the heat output for high/northern fliers?

Other than what I've pointed out? Just wear a lot of clothing :-).

[dust]

OK we have made 1 mod for heat purposes, so far, we built a removable cover for the landing gear area and sealed the top of the landing gear cover pivot point. I think it is pretty air tight.

 

It sounds like we may need one more, a larger or another tube from the back to the front to increase air volume from the heat exchanger, what say you, we can do this easy now.

[Wayne Hicks]

Please remember that you need air flow (delta P) to either cool or heat the cabin. You must have adequate air going out to allow air to get in (either of the cooling kind or the heating kind). Seal up the cabin totally and no air will come in. You'll cook in the summer and freeze in the winter.

 

What some builders do is provide for a cabin outlet of some kind that can be restricted or closed off for winter flying. They open it up fully to allow max cooling air in during summer. They close it off somewhat to allow heated air to come in.

 

The key is to manage the airflow. Seal off the leaks from unwanted air sources, but provide inlets and outlets that can be controlled.

 

....Wayne Hicks

[LargePrime]

It seems an almost sealed plane with air recirculation would be much warmer than trying to heat incoming cold air. Just like a car. Sorry I just had to say it.

 

Seems like the obvious solution would be a blower for the muff. A standard squirrel cage blower would overcome just about any flow restrictions in the tube. Would allow you to recirculate the air. Have very little power consumption. Be very light. We also have a proven model in every car. And a cheap source of parts.

 

There is far more heat in that muff than any car heater core. There is no reason we could not be plenty warm in our canards.

 

It would also adapt to AC very easy.

 

Anyone ever seen any good blower configurations for a cozy?