Designing the ultimate heated undersuit

[RedSeaDiver2]

Its surprisingly hard to feel when a pad or hotspot is "too hot" and many folks have been burnt by heater in the past. Usually from a broken nichrome wire or creased carbon fiber pad. That will create a spot of high resistance and excess heat over a tiny area. So that's a warning...

Otherwise keeping to 40-45C maximum would be wise.

It sounds like we really need to look further into the ways of preventing the carbon pads from creasing to make sure that this doesn't cause issues.

I might set the maximum to 40 degC

 

[RedSeaDiver2]

And what about the cable connection? EO compatible or some "proprietary"?

Will be EO.

I would also suggest to think about a risk analysis fme(c)a.

I am doing ongoing mental risk analysis and trying to engineer out as many potential issues as I can during the design phase, once we have a complete design I might bring that here to the forum for everyone to take a look at and see if they can spot any potential problems that we have missed.

 

[RedSeaDiver2]

For inside the suit 2pin jst / servo connector is the smallest and thinnest i can think of that has good pull out resistance. As for thru suit use what ever the 2 connector types are on the drysuit valve you get.

Are those connectors waterproof as well?

 

[rjack321]

It sounds like we really need to look further into the ways of preventing the carbon pads from creasing to make sure that this doesn't cause issues.

I might set the maximum to 40 degC

Don't put them on places they want to flex. There's really no need to have heat on your arms or even legs for instance. Most folks only use a vest, because 50w on the core keeps your brain and hence circulation to your extremities warm just fine all the way down to just a few single degrees C

 

[RedSeaDiver2]

Don't put them on places they want to flex. There's really no need to have heat on your arms or even legs for instance. Most folks only use a vest, because 50w on the core keeps your brain and hence circulation to your extremities warm just fine all the way down to just a few single degrees C

That is probably OK for a lot of people, but people like me who have poor circulation to the feet & ankles still need heat lower down - there are more people than you would expect like that - my doctor said that it is around 15% of the population that have that issue to varying degrees. I have to wear two pairs of thick socks around home when the weather drops to below about 15 degrees.

If the heat pads are positioned along the long bones then they shouldn't flex too much, and if I can get the right backer material on the heat pads that allows just enough flex then that would be great - that is going to be a little trial and error.

 

[rjack321]

That is probably OK for a lot of people, but people like me who have poor circulation to the feet & ankles still need heat lower down - there are more people than you would expect like that - my doctor said that it is around 15% of the population that have that issue to varying degrees. I have to wear two pairs of thick socks around home when the weather drops to below about 15 degrees.

If the heat pads are positioned along the long bones then they shouldn't flex too much, and if I can get the right backer material on the heat pads that allows just enough flex then that would be great - that is going to be a little trial and error.

Which vest and what's the wattage that you are using now? What water temp and what undergarments?

You absolutely need to have enough insulation that you aren't radically cold on deco should the heat fail. On-gassing warm and trying to deco out cold is a DCS disaster.

 

[RedSeaDiver2]

Which vest and what's the wattage that you are using now? What water temp and what undergarments?

You absolutely need to have enough insulation that you aren't radically cold on deco should the heat fail. On-gassing warm and trying to deco out cold is a DCS disaster.

I'm pretty sure that I answered that up thread a bit

 

[RedSeaDiver2]

A question for the wiring peoples - looking at 18 gauge wire - a two wire cable has an O.D. of about 6.8mm (roughly 1/4") - and any sort of waterproof connector for that is really big and bulky - about 4 inches long. Is it going to be better to have each wire separate so as much smaller waterproof connectors can be used?

 

[rjack321]

I'm pretty sure that I answered that up thread a bit

Was confirming...

Apparently you have zero experience with any heated undergarments at all, you've concluded no existing product will actually work for you - because "reasons"... and you think you can do better than people who have been making drysuit heating products for years

 

[elvenhome21]

Jst are not waterproof but for inside a drysuit it would be overly relevant. Jst would be for disconnecting each element from the circuit. If you want thru suit connector, unless your going to design a new inflator you have to stick with apeks si tech or light monkey connector. Now if your heat suit is for a wetsuit then all bets are off on everything because the second any wire/connector touches salt water it's done for with corrosion