Matt Whiting wrote:

I don't know the area of a typical car radiator either, but I'm betting
it is much more than 3-4 square feet. Also, keep in mind that you only
need to de-ice the leading edge of the wing (look at how much boots
cover). So the area is probably closer to 2' times the wingspan which
means 50-80 sq. ft. one a typical light airplane.

I do. The radiators that several guys have been using to cool their 13B
rotaries have about 14,000sq.in. of radiator surface area. That nearly
100sq.ft. There are alot of very thin fold of aluminum sheet that are
exposed front and back. You'll need both sides of your wings and the
fuselage belly.

Add to that, the radiator is design to turbulate the air in order to mix
it up. A wing is designed to keep the air smooth, and won't fly if you
mix it up enough to to make it a decent radiator.

If you melt the ice on the leading edge, it will refreeze just behind
the leading edge, unless you can keep the laminar layer warm enough.

There could possibly be some benefit to heating the bottom of the wing.
The laminar layer is much thinner, and the heated air would add some
lift energy. But the weight penalty of containing the coolant would be
prohibitive.

Maybe you could have an open system. A hose would spray coolant or
engine heated oil on the inside of the wing skin and then flow back to a
collector. Wouldn't deal with all the engine heat, but it could take a
fair amount of it away.