Forum Index » GEAR » Creating 1" slots/gaps in blue cell foam to allow down to expand under you?


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Kevin Burton
(burtonator) - F - M

Locale: norcal
Creating 1" slots/gaps in blue cell foam to allow down to expand under you? on 08/16/2012 22:31:06 MDT Print View

Today I was playing with my blue closed cell pad and thinking how much of a waste it is to have down compressed underneath me while I sleep.

If only I could get some loft in it then I could retain some heat.

Then I thought that it might be possible to create gaps in the blue cell foam to allow the down to expand under me and into the gaps.

Basically it would like like this... (in ascii art)

A normal blue cell pad would look like this:

*********************

and my idea would be to segment the blue cell like this:

*_*_*_*_*_*_*_*_*_*_

There would be tape connecting the whole thing. Or you could just cut small little circular holes in the foam here and there.

How would I go about quantifying whether it is working and how much heat it would retain.

I guess I could take a setup and place a large amount of hot water in the freezer and then measure how long it took to freeze.

Thoughts?

michael levi
(M.L) - F

Locale: W-Never Eat Soggy (W)affles
. on 08/16/2012 22:47:40 MDT Print View

think ridgerest or zlite, there are already air pockets.

Franco Darioli
(Franco) - M

Locale: Melbourne
Creating 1" slots/gaps in blue cell foam to allow down to expand under you?" on 08/17/2012 00:54:28 MDT Print View

worth a try, that is also how the klymit stuff works.
This was my version of a Neo Air booster, something along those lines too
(folds smaller than the Z Lite but needs another mat. seen upside down in the pic)
Crazy mat

Franco

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Creating 1" slots/gaps in blue cell foam to allow down to expand under you? on 08/17/2012 06:47:14 MDT Print View

Yeah, good idea. Note that for quiters, this wouldn't work. For most bags, the lower section has less down than the upper section. A continuous baffle allows the user to shift down around. But, the lower section typically has about 1/2 the amount of down as the upper section. At least my Marmot, EMS, and WM do. Maybe that's from use, too. I really never noticed till later.

Note than corrogated pads do about the same, if you use them with corrugations up. Perhaps An asymetric air baffling of different sized baffles in a pad night work nearly as well as open holes, like the Klymit (a good pad, but not really suitable for hard surfaces. 'Corse, neither are CCF pads.)

I believe Franco posted on this about a year ago. Note that in most cases, the higher lofting down is likely too fragile to really overcome the tension of the shell. Lower lofts, say 600, would do better by providing less compressibility.

A brief thought of the system involved gives me this system. A bag with high lofting EN800 fill upper, with lower lofting, EN600 fill, lower. When coupled with the loft pockets, I would expect some improvement from a cheaper bag. Perhaps a continueous film lower body with a Klymit like body mapping upper section would do better than the current Inertia design. Allowing a continuous vapor barier at the ground and a more solid pad design, coupled with loft pockets. Just a thought.

George Geist
(geist) - M

Locale: Smoky Mountains
Re: Creating 1" slots/gaps in blue cell foam to allow down to expand under you? on 08/17/2012 09:48:55 MDT Print View

Hi Kevin,

From a thermodynamics standpoint, the solid mat of blue CCF provides a better insulating barrier under you than going and cutting a bunch of holes in it hoping that your sleeping bag down may loft a little into these gaps.

Have you looked at what the insulating value of 3/8" of CCF is compared to 3/8" loft of down?

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: Creating 1" slots/gaps in blue cell foam to allow down to expand under you? on 08/17/2012 09:56:52 MDT Print View

Good for you on thinking outside the box. Maybe a hybrid mat with a thin solid layer layer on the bottom and a thicker slotted layer on top?

Or you could hang a layer of fabric between two trees, put a quilt underneath, another quilt on top, and pitch your tarp over it all. Nope, that's been thought of ;)

Lynn Tramper
(retropump) - F

Locale: The Antipodes of La Coruna
Re: Creating 1" slots/gaps in blue cell foam to allow down to expand under you? on 08/17/2012 14:21:03 MDT Print View

"From a thermodynamics standpoint, the solid mat of blue CCF provides a better insulating barrier under you than going and cutting a bunch of holes in it hoping that your sleeping bag down may loft a little into these gaps."

Exactly my thought. CCF insulates much better than down for equivalent thicknesses. However, it may make your CCF pad more comfortable (though slightly less warm). I know I found a Ridgerest or Z-rest more comfy than a solid CCF mat. I guess it would save a bit of weight too...