Primaloft One vs. Thermolite Micro?

My ONLY experience with Primaloft was 10 years ago with my Caribou Mountaineering summer bag. It lost over 1/2 its loft in 2 summers. Since then I have avoided Primaloft. That said, the new Primalot versions have likely improved its loft retention. Good storage is the key to retaining loft in synthetic insulations.

My experience with Thermolite Micro specifically (they have other versions too) has been very good. I've used my Thermolite Micro jacket and pants insulating layers in late fall and winter backpacking trips. It stuffs down very small and regains loft well, over and over.

As an addition to my 30 F. WM Megalite bag the suit has helped me sleep comfortably into the teens F. On Pennsylvania deer hunting tree stands the Thermolite Micro jacket and pants have kept me cozy under GTX parka and pants for long hours of freezing temps.

As you can see, I'd recommend Thermolite Micro as a good synthetic insulator.

BTW,
Climashield may be as good or better. WHAT WE DESPERATELY NEED IS OBJECTIVE TESTING FOR THEMAL EFFICIENCY AND LOFT RETENTION OF SYNTHETIC GARMENT INSULATION.

(BPL, are you listening??)

most clo/oz …

Edvin,

Thermolite is a Dupont (sold to Koch Industries Invista Division in 2004) insulation family brand with 5 different designs of insulation. Primaloft is an Albany insulation family brand with the different insulations being minor variances of the same design.

Since you posted your question on this forum your implied objective is the least weight for the warmth although you only said "best". Since your application is a belay parka, minimum reduction in warmth when wet is also an implied objective.

Thermolite Micro has a clo/oz value of .598 versus .840 for Primaloft One. Insulation reduction, when wet, for Primaloft One is less than 10% and is approximately 25% for Thermolite Micro. Based on your explicit and implicit objectives, Primaloft One is the better alternative for this application.

There is no BEST insulation for all applications. For different sets of objectives there are different optimal solution sets. Thermolite Micro uses .9 denier round polyester fibers; 55% of the fibers are slicked to prevent moisture degradation, 27% are dry, and the remaining 18% are binders to keep everything aligned. This is an excellent insulation for items like gloves, boot insulation, and belay jackets that make you look thin (smile). Primaloft One also uses polyester fibers but two different fiber sizes are used and they are aligned to mimic a down cluster. 85% of the fibers are .5 denier and 15% of the fibers are 4 denier. No binders are used and all of the fibers are slicked to prevent moisture degradation.

Thanks alot Richard, that's excactly the kind of information I was after!

As you assumed, warmth per weight is definately the most important consideration and second is it's ability to stay warm even when wet.

Just a coupld of more questions, you said that Primaloft One doesn't have any binding fibres in it, is it because of that, that you have to quilt it every 15 cm or so? I know you don't have to do that with Primaloft Sport, do you know what's the difference between the two?

Also, since Thermolite's fibres is thicker, they shouldn't lose so much loft over time and also be more resistant to compression(which I consider good since you squeese less warm air out of the garment when moving around) right?

I second the synthetic down as "best". Copying what has worked for a very long time before we even invented the word "synthetic" makes the most sense to me. Its how we've overcome a lot of obstacles as the mighty human brain master of his synthetic universe.

Edwin,

The fibers of Primaloft One are thermally bound as opposed to being adhesive bound. Most adhesives add weight and some increased water gain. You need to quilt it tightly because the silicone slickened small fibers will migrate away from pressure points.

The thin fibers of Primaloft Sport are .9 denier versus .5 denier in Primaloft one. The tradeoffs are that Primaloft Sport is more durable than Primaloft One at the expense of being less thermally efficient (.74 clo/oz versus .84 clo/oz).

I assume by Thermolite you mean Thermolite Micro since that was mentioned in your original post. Yes, Thermolite Micro won't compress and squeeze out warm air primarily due to its geometry and secondarily do its fiber size. It is the standard insulation for high altitude sky diving suits for this very reason.

Hi, I can vouch that Primaloft One is VERY warm for the weight and thickness. I have 2 jackets with it. A Patagonia Micro Puff and a First Ascent Igniter. But, I always feel, don't know if it can be proven scientifically, that synthetic insulated jackets "breathe" less than down equivalents. Maybe thats why the synthetics are sometimes so warm without having to be really thick. just a though.

Hi,

Is Themolite Micro the same as Mountain Hardware's Thermic Micro?
Somewhere online a rep claims that Thermic Micro "compares favorably" to Primaloft One, but no details I can find.

Any knowledge of Thermic Micro's performance vs. Primaloft One?

Thanks!

What would we do without Richard Nisley? Thanks for the valuable info Richard.

Ryan