Page 1 of 1

Heat transfer through arming materials?

Posted: Thu Jun 18, 2009 4:02 am
by Aaron
Hi,

I was wondering if people have experienced different heat transfers through different materials?

I think that the steel conducts heat away from me and I've experienced that mail is actually quite cooling. Plastic has made me sweat a lot and padding does that too. Cloth seems to breathe. Leather seems to absorb moisture but not heat.

Any experience?

Any scientific evidence?

With thanks,

-Aaron

Posted: Thu Jun 18, 2009 5:06 am
by Signo
Well, metal is a good heat conductor, unless something like the sun heat it above your body temperature, it will act like a heatsink, otherwise it will turn in a oven :D

Posted: Thu Jun 18, 2009 5:28 am
by Glaukos the Athenian
Signo,

You are correct, but there is more than heat conductivity going on here.

First most armour is not worn in a static, resting situation but one in which the wearer generates an unusual amount of heat, which is physical exertion.

Second is that said exercise also produces perspiration and a lot of moisture "trapped" (or not) between the skin of the wearer and the outer shell of whatever armour you wear.

Third, most people wear some sort of padded garment, arming coat, gambeson, etc under their amour.

We do most of our fighting in hot, sunny days in a temperate part of the world, or indoors at winter practices. I have heard many complaints about heat, and suffered its effects as well, but I have not heard that much about cold.

John Keegan mentioned in "Face of Battle" the discomfort of English men-at-arms at Agincourt, waiting for action in their armour suits, in the chilly October weather after a dampening rain. But this is not that common in SCA contexts.

The main issues as I have seen it and experienced it is hydration, physical fitness, experience in wearing the actual armour, and the number and nature of layers of under garments.

If you are wearing a moisture transfer type shirt, AND you can get air to run under your plate armour, you should be quite cool. Personally I have shed my torso padding, and now I wear my muscle breastplate over a tunic and an under armour shirt. My current kit is the coolest I have used since I started fighting. Once you allow air to circulate inside your armour, sweat alone will keep you cool, if you hydrate correctly and know the limits of your exertion capability.

That is at least my limited experience.

Glaukos the Athenian

Posted: Thu Jun 18, 2009 12:15 pm
by chef de chambre
Metal does not only conduct heat, it conducts cold (and, excitingly in a thunderstorm, electricity), in reference to the Keegan commentary.

That said, people were heating up enough to significantly dehydrate in the middle of a blizzard at Towton in 1461, leading some to seek comfort, and temporarily remove a bevor, or raise a visor, and take liquid refreshment, and be killed for it, as Lord Dacre famously did.

Posted: Thu Jun 18, 2009 12:54 pm
by Signo
I always wear a garment that is something between a gambeson and a purpoint. Call it a soft gambeson, or a thick purpoint. It has vertical wool stuffed channels and it's made of linen. When I sweat I can feel the air flow from below and exiting from the neck opening, like a sort of chimney, All I need to do is to loosen my belt. This garment drink most of my sweat, and get dry as soon as I remove eventual armour over it (a coat of plates).
Actually the only plate part that I carry over it are arms, that does not change much in term of heat.

Posted: Thu Jun 18, 2009 1:24 pm
by Vladimir
I often noted that I was cooler when I wore my maille under my lamellar than when I did not.

It was a trade off. Extra weight to carry but cooler or lighter and warmer.

Posted: Thu Jun 18, 2009 1:38 pm
by Owyn
I've heard from a number of folks that mail acts like a radiator. I gather it collects heat from contact with your body, and then expels it into the air very effectively because it has so much surface area. Anecdotal; haven't worn mail often enough to experience this myself. But interesting.

Posted: Thu Jun 18, 2009 1:44 pm
by Derian le Breton
It certainly makes quite a bit of sense. High surface area, extra air layer, lots of contact with inner and outer layers, relatively high thermal conductivity.

-Derian.