I believe because it is a humectant, pulling moisture off the skin resulting in cooling of the skin due to evaporation.
Also, when the droplets of vapor/water hit they evaporate and cool the skin as well.
You are close.... Its not so much the humectant properties that are causing this, but does boil (semi-intentional pun) down to conservation of energy. You used power in the form of heat, generated by electricity to turn liquid into vapour. That vapour wants to turn back to a liquid/semi-liquid (e.g. the residue left behind on cold windows if you are vaping heavily), but to do this it requires energy. It takes that back from the air around you in the form of heat.
Thus the energy us conserved, the circle of physics is complete and Newton is happy.
Ok, I was under the impression that the vapor is at higher energy than the liquid (E obtained from heating element), and therefore wants to lose E in the form of heat to return to its more stable phase.
But I think what you're saying is that the phase change requires E to shift from vapor to liquid (heat of vaporization or whatever its called), pulling in heat from the environment to do so?
I knew I should have paid better attention in physics.
You are thinking along the right lines. Think of it like this: to compress air into liquid you need pressure. To vaporise eliquid into a vapour you use heat. Different things (I say things, as I'm talking about mixtures and molecules) are in varying phases at room temp. Therefore the ice your freezer used electricity to make from water will need to recoup that energy to turn back to its room temp form (i.e. liquid). This is ignoring the fact that your freezer uses the same process to extract heat from inside and expel it via a heat exchanger on the back.
In the case of eliquid the heat comes from the coil, energy from the battery. The universe wants that energy back and it will take it!
This is the most likely correct answer for the sensation OP is describing.
I'm not sure why you are getting downvoted, as I mentioned, he was close and his theory was the best posted. Science is all about making an educated guess, and he had the spirit but not the mechanics right....
Also, I'm not so sure he's wrong at all. Our bodies are conditioned to experience "cooling" when our skin is wet. Any VG aerosol exposed to the air will be attracting moisture like crazy. So it should feel cool. Also, while your explanation re:energy is correct, I think most of what you're talking about happens long before vapor is exhaled. If our temperature control mods are even close, the hottest thing in the atomizer, the coil, is up over 400F, by the time we inhale it, the temp of the vapor mixed with fresh air is down close to our body temp, otherwise you would feel a burning sensation on every inhale. By the time you exhale, it's probably about 98F, and cooling rapidly as it spreads out into the air. But that would make it feel WARM, as it loses heat to the atmosphere (or your skin), so the humectant factor seems to be dominating the total reaction, as far as how it "feels".
I know what you mean. Even when I blow it on my skin, and yes I know it's because I'm blowing it on my skin, but it feels different and kinda cool. Idk why it seems that way but it does
I would hazard that blowing on your skin is more to to with air-cooling. Blowing onto wet skin (providing your not in a very humid environment) will have more effect as the water will take the heat to change phase into a vapour (i,e, evaporate).
The vapor is moisture.Ever feel the mist coming out of a humidifier, same feeling. I would think the droplets of water are cooler than your skin and the surrounding ambient temperature.Also possibly the evaporation mentioned above too.
Humidifier just feels damp. Vape doesn't feel damp, just cold.
Actually even if the vapour is the same temperature as the air (which it would very quickly become after exhaling) it would still feel colder. It has more to do with the fact that water has a much higher thermal conductivity, so essentially you just feel the difference between your skin temperature and air temperature more.
Edit: I stand corrected, while what I said is not incorrect an important part of evaporation being endothermic reaction is missing, that would make it feel colder too
Very good, glad you can explain it better than I. I just knew it was from the moisture.
I am very sure it is not simply the moisture. Ever sprayed butane on your hand? Or any other substance that is changing from liquid to gas/vapour? In order to re condense back to its room temp state it needs energy. It will take this from anything it can that has more.
I have a question semi related, ever since smoking ecigs, when i go out in the cold weather i can feel the cold more in my lungs than rest of my body. ive even had a couple episodes where i could barely take a breath in cause my chest area felt ice cold and shivering type of feeling. anyone else get something similar? could be completely unrelated
See my replies above, I would hazard a guess that is what is going on. Cigs smoke is a mix of hot air, particulates and gases from oxidation of tobacco, so it won't want to condense back into a liquid (although the tar will, as that is a very viscous liquid).
hmm im still not sure as to why. you think the vg and pg in my lungs takes the moisture out of the cold air i breathe and that makes it feel colder? its not necessarily while im hitting my ecig. when i hit the ecig it actually feels a little better cause the air is warmer. but just like right when i go outside and it is cold out. and i know cigarette smoke is really hot and stuff but i havent smoked any cigs in like 5 years.
It is definitely the evaporation of water vapor off skin. Here in Arizona where it is very dry, evaporative coolers (AKA swamp coolers) are used as an energy efficient alternative to air conditioning. I used to live in the midwest (humid!!!!) and had never heard of such a thing. Water is run over pads, and a motor/blower pull outside air through the water soaked pads, blowing moisture laden air into the room. Its amazing how much it cools, assuming it is not the rainy season.
Evaporative cooling is what you are feeling. I have also noticed since it's been getting colder here, vapor sticks around longer outside. Clouded up my friends porch one night, pretty entertaining :)
/r/deeper_diy has a post about this right now. Its an interesting read. Basically there are cooling agents like menthol that impart the feeling of cold. Koolada is known to give this feeling, but while not imparting a menthol or mint taste.
Cooling agents. Koolada. Menthol.
but I dont use any of those
Well then it would help if you told us what you used?