Sleep Mat Development

[Michael F]

I’m making an inflatable sleep pad starting with a light un-insulated air pad with an r value of about .95

I’m attaching to the sleep surface a thermoconductive material made to draw heat way from the body. This is so that my body heat efficiently transfers into the air chamber and warms the air inside more efficiently.

The side and bottom shall have a heat refelective material designed to keep the heat from flowing out and keep the remaining conductive sleep layer actively exchanging heat for the sleeper.

The sleeper should lie directly onto the pad without insulation between the pad and the body, insulation should then be appiled over top the user in layers. This is going to work with a layered quilt sleep system I am designing. This should in theory create a greater pocket of warmth efficiently.

Just something I will be testing soon.

[Greg Mihalik]

“The side and bottom shall have a heat [reflective] material designed to keep the heat from flowing out …”

Radiation loss is only one issue.

Since you are optimizing for convection, “actively exchanging heat for the sleeper”, how will you minimize the conductive loss through the sides and bottom?

 

[Michael F]

The sides and bottom will be insulated on the outside… with an inner heat reflective surface on the inside. The insulation layer traps the heat as best as possible, as the heat reflective material emits it back to the conductive surface up top. The sleeping pad can go inside of a sleeping bag potentially as well. allowing for more insulation around certain areas

Still ironing out the concept but Ill be building a test soon :)

[Mark Fowler]

I am curious about the “benefit” of creating a layer of warm air in the mat rather than keep as much warmth as possible close to the sleeper. In all mats there is some warming of the mat by the sleeper – why try to maximise this effect and then have to increase the amount of insulation at the bottom surface of the mat to compensate.?

You posted while I was typing. Reading your post – I suspect you are just going to end up with a heavier than necessary sleeping system. People usually adjust for their warmth levels using clothing, venting etc so already have that adjustability but it varies from person to person and night to night.  For instance many get cold feet but my feet tend to run hot compared to my torso – no bed socks for me.

[Ben H.]

<p style=”text-align: left;”>I’m sorry but I don’t think you understand heat transfer. Warming up a pocket of air around your body does not help better insulate your body. That only aides in conducting heat away from your body. You will in fact be aiding heat transfer away from your body.</p>

[Michael F]

“Warming up a pocket of air around your body does not help better insulate your body.”

I thought that is how down works?

Its important to not I dont come here proclaiming a revolution or advancement …just stating I will be making a test soon. Im well aware that it might not work.

[Ben H.]

No that is not how down works.  Down traps small pockets of air throughout the document.  Air can exchange across down, but it does not do so freely.  That prevents the creation of convective cells forming.  These trapped pockets of air are all at a different temperature.  This creates a large temperature gradient across the insulation.  The large temperature gradient prevents heat flow.  What you are planning on doing will allow convective cells to form.  Now your temperature gradient will be brought closer to the cold ground, enhancing heat transfer.  If what you propose worked, then a Neo Air x-therm would be just as insulating as a pool floaty.

[Anonymous]

Michael, look up the debates here about whether to use CC type foam on top or below an air pad.  Most folks agree that it feels warmer to use foam on top of an air pad, vs below it.

That’s a good real world phenomena which might indicate that you’re looking at this from an incorrect angle most likely.

[R]

Equally important – how do you plan to test this?

[Author]

Posts