Posted by: ETSU Pride

Thinsulate - 08/20/12 09:26 AM

I'm planning to make a under quilt for the hammock, and have a question about Thinsulate. The company selling it is selling them by the width, does this mean I do not have to create baffles and just layer the Thinsulate between the shells as if it was Insulex?

Secondly, how do I calculate a temperature rating? There formulas on the hammockforum to calculating loft and down for temperature rating and I asked the same question on that forum, but no one has an answer, yet.
Posted by: PerryMK

Re: Thinsulate - 08/20/12 02:22 PM

From Jardine and consistent with other sources:
ETR = 100 - (40*Th)
where ETR is est temp rating and Th is thickness.

So for a 0 degree estimated temperature rating:
0 = 100 - (40*Th)
(-100) = -(40*Th)
100 = 40*Th (divide both sides by -1)
100)/40 = Th
2.5 = Th
So with 2.5 inches of loft it theoretically should be good to around 0 degrees.

As Yogi Berra said, in theory, theory and practice are the same. In practice they are not.

Posted by: ETSU Pride

Re: Thinsulate - 08/20/12 03:01 PM

Hmm. Thanks a lot!
Posted by: CamperMom

Re: Thinsulate - 08/21/12 07:44 AM

Does the R rating change dependent on the insulation used? Somewhere in the old memory bank a bit wants to come up with Thinsulate being touted as providing more warmth with less bulk, hence the "THIN" in Thinsulate.

Posted by: PerryMK

Re: Thinsulate - 08/21/12 06:24 PM

The theory is that the material doesn't provide insulation, the trapped dead air space does. Therefore the type of material shouldn't matter much. Some materials are better conductors/worse insulators than others (copper wiring vs aluminum wiring), but I'm not convinced that one fabric is noticeably better or worse than another.

My opinion, to be taken with as many grains of salt as you like, is that the dead air space matters most with any fabric insulation. The big difference will be in how long the fabric (filament, poly, down, whatever) is able to maintain it's dead air aspace, aka loft.
Posted by: CamperMom

Re: Thinsulate - 08/22/12 08:18 AM

Yes, I understand this. Maybe it ia just hype (AKA, marketing, but Thinsulate claims to be made up of thinner fibers, therefore trapping more air in a thinner overall thickness than down or other synthetics. Google Thinsulate to find THEIR claims on how R values compare.

That said, I prefer down to synthetics for most applications, but I may make a Thinsulate underquilt with a poncho/tunic conversion. This may be a better choice to wear under my pack as I hike than fragile down.