Bookworm wrong...........wrong ..........wrong
carb heat CAN cause icing in the venturi of the carb and starve the engine of fuel. air below 0 degrees still has a moisture content. However its frozen and will not adhere to the carb venturi, fuel jet etc but bounce straight through, but..... heat that air to just above freezing and the moisture will then freeze as it goes through the venturi (remeber the theory :- increase velocity and temperature decreases ) when it freezes the moisture will then adhere to the inside of that carb.... guarenteed.
faultygoods
Are you suggesting that the moisture content of unsaturated air is somehow "frozen"? That's interesting physics. I've come across gases, liquids and solids, but my states-of-matter text for some reason omits the "frozen gas" state.
If you have solid ice suspended in the air, i.e. you are flying in glaciated visible moisture, then your mechanism makes sense, as I mentioned at the start of my first post. But if the air is unsaturated, the moisture is
gas -- it's not "frozen". And if you cool the air to below its dewpoint, it will freeze where you cool it -- in the induction system constrictions. It doesn't "bounce through" anywhere just because the temperature of the water vapour started out below zero.