heat loss with backplate?

[cecilb63]

When I used to ice climb I would sometimes get cold feet due to the steel in the crampons drawing heat away from my foot. That's not a problem really anymore due to plastic boots and better designed crampons but I noticed a similar potential with my new backplate.

This last weekend I was diving dry in 37 degree water and definitely could feel the presence of the cold steel on my back. Was it stealing heat away from my core? It seems if i can feel the cold of the plate then I'm losing heat.

My solution would be to glue thin 1/4 inch ensolite pad or the like on the inside of my plate to fur the plate off my back thus helping preventing any heat loss.

Good idea? Bad idea?

 

[D_O_H]

I'm no scientist, but I don't think it's the same as your crampons. When ice climbing, you're surronded by air, which isn't really good at stealing heat from your body. I imagine cold steel crampons are better conductors of heat than air and thus could steal heat from your feet faster than the air would.

When you're diving, you're surronded by water, which is a much better conductor of heat. I imagine the water can steal your heat as well as, if not better than, the steel backplate, so you probably wouldn't gain anything from insulating the backplate. Interesting that you felt cold in that particular spot, though. I suppose it could be chilling you if the backplate was chilled below the water temp, but this seems pretty unlikely in 37 degree water.

That, and I've never noticed any heat loss when diving with my uninsulated steel backplate.

 

[RiverRat]

Hummm I never thought much about it myself. I suppose it couldn't hurt. I just wonder how much surface area you really have in contact with your back and just how much thermal transfer there is? I would guess not all that much. What is ensolite BTW?

 

[cecilb63]

Ensolite is a closed cell foam pad, like something a backpacker could use for sleeping pads.

 

[CIBDiving]

Ensolite is a closed cell foam pad, like something a backpacker could use for sleeping pads.

Then you might as well use a pad of 7mm neoprene.
I'm not sure it you feel the plate "drawing" heat out or simply the effect of the plate compressing the insolation in your suit at the point of contact. If the latter I'd add a layer of fleece on the back of what ever you use for underwear.

 

[Mike Newman]

When I used to ice climb I would sometimes get cold feet due to the steel in the crampons drawing heat away from my foot. That's not a problem really anymore due to plastic boots and better designed crampons but I noticed a similar potential with my new backplate.

This last weekend I was diving dry in 37 degree water and definitely could feel the presence of the cold steel on my back. Was it stealing heat away from my core? It seems if i can feel the cold of the plate then I'm losing heat.

My solution would be to glue thin 1/4 inch ensolite pad or the like on the inside of my plate to fur the plate off my back thus helping preventing any heat loss.

Good idea? Bad idea?

What an unusual issue - but relevant to me, because I'm diving these days in 33F water using a steel backplate. The good news is that I haven't noticed any 'draining' of heat - but I haven't really been looking for it. Other replies are cogent - explaining the distinction between in-water conditions and those on land. I still have an instinctive feeling that the insulation couldn't hurt!

Thanks for a great topic.

 

[bradshsi]

I'm no scientist, but I don't think it's the same as your crampons. When ice climbing, you're surronded by air, which isn't really good at stealing heat from your body. I imagine cold steel crampons are better conductors of heat than air and thus could steal heat from your feet faster than the air would.

When you're diving, you're surronded by water, which is a much better conductor of heat. I imagine the water can steal your heat as well as, if not better than, the steel backplate

Actually, steel has a thermal conductivity of about 50.2 W/mK compared to 0.614 W/mK for water. So in relative terms, the steel can conduct heat 82 times more effectively than the equivalent thickness of water.

I suspect there are three effects at work here:

1. Some of the heat removed is going towards raising the temperature of the backplate.

2. Some of the heat is dissipated into the water as the slightly larger area of the backplate acts as a heat sink.

3. The suit insulation underneath the backplate is being compressed, reducing it's effectiveness (As pointed out by CIBDiving).

To answer your question, putting a foam pad on your backplate would certainly increase the insulation and reduce heat flow. The reduction would depend on the thickness of insulation and it's thermal characteristics.

 

[mahjong]

Ditto the "I'm no scientist" caveat, but if your SS backplate can be pulling heat from your body--ie, if the heat from your body is even coming close to reaching your backplate--then perhaps you are underinsulated. Especially given the heat-conducting properties of water--as mentioned above--you want your body well unsulated with underwear so as to keep your body heat away from the outermost surface of your drysuit, lest the water will quickly and efficiently draw it away. Moreover, unless you have quite a setup, you are probably losing far more heat through your head and hands than through your core/back area, where most people pile on the insulation. I wear a compressed neoprene drysuit (DUI CF200), which would probably be roughly equivalent to the pad you intend to apply to your backplate, so this alone--on top of my UnderArmour and multiple layers of Polartec--might explain why I never found issue with my backplate, even in 35 degree water. That said, I suppose it cannot hurt to pad your backplate--and I might note that many manufacturers market backplate pads (most with pockets, some without).

 

[spectrum]

Good idea? Bad idea?

I don't think it is a conduction issue. However with an E7-100, DSS singles rig and the weight plate kit you have a very negative object pressing down on you making it impossible to maintain loft in your backside undergarment. Your computer also made you 2 degrees colder than I was.

Pete

 

[countryboy]

Wouldn't the wing be holding you up [your tank up], essentially you are suspended by your straps, so the wieght of the tank should not be pressing on your back.. The tank, wing, backplate are essentially weightless.

Just a thought..??