First off I just put in a frostheater so I'm more familiar with the piping under my car and the only plastic that is a low spot is the intercooler piece with the odd clamp you have to pry the arms apart on. Can't see anything that looks like the pictures posted earlier in this thread. That said, the tubing had no moisture in it except for some black oil so I'm not going to drill a hole or anything yet. Though I did do a little experimenting just to test my idea.
Ok, just for fun, I'll take a stab at completely ripping your idea apart
You are too kind.
Three things come to mind immediately - first, the amount of heat required to actually boil the water out - assuming that little heater could manage it (doubtful, especially in winter ambient temps) - would be (with regard to IAT) the functional equivalent of just completely bypassing the intercooler - or worse.
I didn't have a 12v 50 watt heater but I do still have a spare 120v 100 watt heater (from when I lived in North Pole, Alaska) to experiment with. And you can get 100 watts in 12v so I went ahead and got some data points. I used a metal plate measuring 6"x6" and 0.074" or 5/64 or 1.90mm thick. Which if made into a tube would be 1.91" in diameter. Temps were taken with my craftsman professional dmm with ir temp sensor in Fahrenheit.
0:00 26 (it is winter)
1:00 78
2:00 106
3:00 140
4:00 136*
5:00 168
6:00 190
7:00 200
8:00 229
*I was holding the plate down but the edges got too hot and I accidentally moved it a bit and had to reposition it so the temp reading was off.
Therefore yes it can get above boiling temps even when the ambient is below freezing. In regards to actually affecting the iat.. It has no where near the surface area to affect the air passing over it, if it was heating up a long tube (feet) then you might get a few degrees higher.
Second, the small amount of air space inside the system would severely limit, if not prevent, complete evaporation from happening, especially
True if it was done with the engine off. Which is why I said 12v so it could operate while the engine was running, taking the moisture away immediately. For that I don't think it would have to boil the moisture as heat would speed up evaporation either way.
third, you would have to be heating this thing while the car is parked (since that's often when the accumulation of water occurs), so you would need an external power source to avoid draining your battery.
It sounds like for some there is quite a bit of moisture accumulated after one trip and if it was all frozen and then thawed out you would be screwed unless you had a hole. For ones where the moisture accumulates over time then a heater on a metal intake tube might well indeed keep it in check.
Gravity is free and ever-present, so some mechanism for simply draining the charge pipe is by far the simplest and most elegant solution - either by drilling the hole or installing some sort of drain valve as has been discussed.
I only replied to say it could work, not that anyone including me would do it as I don't have any issues yet but if no one thought outside the box where would we be?
A hole is definitely simple, there are medical supply places where you can get check valves with as small as a 1/16" port size.