How Much Faster Does Water Conduct Heat Than Air

Bryan1108

This is just asilly question that somebody asked and it was fun because a dozen different intelligent men hemmed and hawed about it and gave some truly silly answers. I kind of want to see how this board does with it.

If I am continuing around and the temperature of the air is 90 degrees, then I feel hot and sweat. If I accept a shower and the temerature of the water is ninety degrees, I feel cool and shiver. Why?

mathman

Office of the answer may be that the shower water on your skin is evaporating, which has a cooling issue.

DaleSwanson · Apr 24, 2017

From http://en.wikipedia.org/wiki/Water_(molecule)#Heat_capacity_and_heats_of_vaporization_and_fusion":
"H2o has the 2d highest specific heat chapters of any known chemical chemical compound"

This means it takes more heat energy from your torso to raise the temperature of water to equal your body temperature, compared to air. Besides h2o's thermal electrical conductivity is college than air'southward (0.6 vs 0.025 Due west/(m·Grand)), which means heat moves easier to water. In simpler terms water can absorb more heat from you, and practice information technology faster than air, thus leaving yous with less oestrus, and feeling colder.

Edit: Ii more factors just popped into my head. First at these temperatures water is liquid and air is a gas. Therefore, h2o volition be more dense than air, meaning there will simply be more of it close to you. Secondly air will exist adequately static, whereas water will be pulled by gravity and only in contact for a few seconds before going downwardly the drain (along with the rut you gave it), and being replaced with new water not nonetheless warmed by you.

So we have a combination of water having a college heat capacity, college thermal conductivity, college density, and existence constantly moving. In that location is more of the water, which absorbs oestrus faster, and absorbs more earlier reaching equilibrium, and information technology is constantly being replaced by fresh unwarmed h2o. Information technology'south a wonder we don't become hypothermia in the shower.

russ_watters

It'south a wonder we don't go hypothermia in the shower.

Well that's where the OP leads us: we would go hypothermia in the shower if the water temperature were much cooler than torso temperature. That's why y'all want it warmer!

rcgldr

Peel temperature is less than body temperature, and the skin releases rut into the air every bit part of internal temperature regulation. Since air has a much lower rate of heat capacity than h2o, the comfort zone for air is lower wider than it is for h2o.

http://www.wonderquest.com/skin-temperature.htm

GT1

The corporeality of heat your body loses to the environment is Q=H*A*deltaT, where H is the convection heat transfer coefficient, A is the surface area, and deltaT is the temperature divergence between your skin temperature and the water/air temperature. For the same temperature divergence yous will lose much more than estrus in water and then in air because the rut transfer coefficient in water is much much bigger and then in air. If your skin temperature is 90 and the water/air temperature is as well 90, deltaT=0 and you won't lose oestrus (by convection).