Does anyone know how to compare the differrent types of synthetic fill in terms of say warmth, "compressability",  water resistance and so on?   e.g.  Primaloft, Thermolite, Thinsulate, Prism.

Also, I have a 2002 Montane Solo (great bit of kit) but i don't know what the fill material is.   Anyone got any ideas?

Cheers

According to a quick Google the Solo is Primaloft One.  Which is currently about as good as you'll get, but See here for news of upcoming improvements.

Pete. 

Thanks Peter 

My Solo jacket is nowadays used as my everyday coat so I'm looking for a replacement to go in my rucsac for a warm layer at rest stops.... I should have added this to the original post. Oops

This is why i'm interested in a comparison

There's this in medium

I have one of these from the 2006 season, it's my favourite insulated jacket.

Oops! for some reason that link won't work. Anyway it's the Millet Sawtooth from www.hikekit.com and it's £69 in their sale. The problem is, you will want to wear this everywhere.

I had the same problem with my solo and now I don't like going anywhere without it. So I am keen to get something to replace it for rest stops. i think the sleeka is good but  quite heavy for something that sits at the bottom of the rucsac most of the time.

The effectiveness of thermal insulation is measured in CLO, which was originally defined so that 1 CLO equalled the insulation given by a business suit.  A three season sleeping bag is about 9 CLO.  I lifted what follows from the backpackinglight.com site:

This might interest someone on here: 

There is a problem with generalising Clo values of synthetic wadding. The biggest problem here is that the Clo/oz figure is not always the same as the fill weight increases.  We have tested all of the synthetic waddings above and many more at a range of weights (60g, 120g, 170g, etc). We have found that it is possible to have a fill were the Clo/oz figure is higher on a 60g sample than on a 100g sample. It is never to the point where a 60g jacket is warmer than a 100g jacket for a given surface area of wadding but it can be closer than you think. I am sure this is due to the manufacturing process changing slightly as the wadding gets thicker.  

In response to the message above (I know you are just using info you found): To say Climashield XP is 0.82 Clo/oz may not be true for all weights of wadding and for this figure to be of any use when working out how warm a specific jacket is you would need to know how many metres of fabric were used and were it is used. Like all these things the fabric selection is only one part of the product. 

Keith Hutcheon – Designer – Mountain Equipment

Frum,

do you mean Clo or Tog in your sleeping bag rating? My 'back of the envelope' calcs suggested that 9 Tog would be typically warm enough for an adult of average metabolic rate to about -5C 

http://www.outdoorsmagic.com/forum/forummessages/mps/UTN/21217/URN/5/dt/4/srchdte/0/cp/2/v/8/sp/

I Clo = 1.55 Tog, so 9 Clo is about 14 Tog (which is very warm for a sleeping bag...)

The problem is that adding weight of insulation (through greater layer thickness) doesn't increase the warmth linearly; the more you add, the more the layer below is compressed. The US army have a recommendation that the total Clo of an ensemble of clothing is about 40% less than the sum of the Clo of each garment (if memory serves).

And there's another problem hinted at in the linked thread... Tog / Clo or any standardised test of insulation gives a limited picture. Heat is lost to the environment through convection, conduction, radiation and evaporation. Tog / Clo don't consider evaporation at all. And they measure the cumulative heat loss by all means at standardised temperature and conditions. This is, I think, why the Tog rating of closed-cell sleeping mats is a bit misleading : they function primarily to cut conduction to the ground so measuring them on the standard Tog testbench doesn't really highlight their strength.

As Keith says, design, cut, fit and method of use can all have a huge impact on insulation. In the end, the manufacturer has to make a trade-off between function and price, weight and bulk etc. A good mountain designer will end up with a product that keeps you warm in the mountain conditions you are heading into and that is the end of the story IMO. They have to use marketese to sell the product, claiming that their choice of fill is the best for whatever reason - I tried asking both Integral Designs and Rab why they used PL Sport instead of PL One (which Primaloft claim is their premium product). Neither said it had anything to do with PL Sport being cheaper (whilst still allowing them to put the PL label on the garment). Maybe PL Sport handles moisture better - maybe it doesn't - but I still think the Rab and Integral Designs garments are very good options because they are well considered. Likewise PHD using Thinsulate. And Haglof's Barrier keeps people nice and warm and doesn't use any of the above to my knowledge.

John

And Keith...

come back to us when you have found a way to use aerogels in insulative clothing...

You are right, as usual, about the 3 season sleeping bag rating.  I should have said 9 Tog (or 6 Clo).