This video is a response from subscriber to compare the air permeability of Primaloft One vs. Alpha. As you can see, Alpha has much better air permeability.
I think the test is pretty much valid because it simulates what's really important on insulated jackets which is compression. And by compressing the fabrics you can get an idea how it would work if compressed. Down or synthetics don't work well if compressed and if the permeability is poor you'll get cold. In other words, it doesn't matter the face fabric, it should work no matter what, those jackets are relatively expensive. If the face fabric was a bad choice than the whole jacket will behave poorly in the outdoors.
Wow! Thank you so much for the response! Well, that just about says it all. There really isn't any compairison between the two, Alpha wins hands down. Unfortunately this makes me like my Patagonia nano puff less but fortunately now I know for my next purchase. I have always defaulted to an R1 pullover and a Marmot Vapor Trail soft shell vs my Nanopuff for high aerobic activity but I can definitely see Polartec Alpha as a replacement. Thanks again for opening my eyes and a great test!
This is a pretty interesting discussion. I wonder if the face fabrics have anything to do with the results of this test. When I found out the breathability of Polartec Alpha is only 3,349g H2O/24 hr (From Kjus 2014-15 catalog), I was floored. Considering it claims to be twice as breathable as its leading competitor, I began to wonder why anyone would buy a face fabric with a higher breathability. I also wondered about the breathability rating of my fleece mid-layer. Could it be that the steaminess I feel at times in my supposedly highly breathable jacket be due to my mid-layer rather than my shell jacket? Is there any insulator that even approximates the 20, 30 or even 40k breathability of the new fabrics out there? If the breathability of the insulating material (or midlayer) is not as breathable as your shell, it seems as the breathability of your system is bottle-necked by your insulation? If so, why buy a shell with a breathability over 5,000? Would a more breathable shell help the insulating material (or midlayer) in impeding moisture buildup, and if so, would that impact be significant? I always assumed that all fleeces and insulating materials would be more breathable than any waterproof shell fabric, as they are not-waterproof, and I can see, and sometimes blow air, right through them, so this has me thoroughly perplexed. Please share your thoughts and educate me if you have some insight on this. Also if you know of sources of where I can get the breathability, CFM or air permeability ratings of different insulators, let me know.
Your video is misleading people. Both of these insulations have high air permeability. The air permeability of the outer fabric and the lining fabric is what is causing the decreased air flow. Take the insulations out of the jackets and test them if you want to compare apples to apples. For this video you should be comparing jacket to jacket.
And I quote from the video " ...the reason it is so much more air permeable or breathable is that it ALLOWS the manufacturers of the jacket to use a far more OPEN WEAVE FACE fabric and LINER fabric and THAT is where you are getting a lot of the increased air permeability...."
Out of interest, what are the face and backing fabrics of the jackets you have tested? Polartec Alpha just doesn't seem to add up to me. The only advantage to primaloft one I can see is that it allows manufacturers to use more 'breathable' fabrics on the jacket (especially the mesh back). Many alpha jackets have a mesh back which I can see would increase breathability by a long way over conventional fabrics. Alpha is less warm than primaloft one, so the only reason to buy alpha would be its claimed increase in breathability. I thing that the 'controlling resistance' to breathability of a synthetic fabrics must be the outer and inner fabrics. The breathability difference between primaloft and alpha (only the actual insulation) is very small compared to the outer fabric. Therefore the only advantage of alpha over primaloft is the ability to use more breathable outer/inner fabrics. Marmot have used pertex quantum in their isotherm jacket, therefore it has virtually the same breathability as a primaloft garment with the same outer fabrics. My second point is about the 'air permeable' nature of synthetic insulation outer fabrics. Synthetic insulation works by trapping a warm layer of air close to your body. With alpha's supposed intended use of more air permeable fabrics, surely the wind will rob you of warm air you have trapped, therefore rendering your insulation somewhat useless! I can see the point that polartec is trying to make, however I don't think the science behind it backs thier claims up. IMHO, the only thing an alpha jacket does a slightly better job compared to a primaloft one, is as a midlayer due to it's increased breathability beacuse of the mesh inner fabric.
Nice review, btw do you know what is the clo/oz value for Polartec Alpha? Also, because of bonding Alpha insulation to more brethable materials does it make insulation less warm?
Yes - Alpha is not as warm as Primaloft One on a warmth to weight ratio. I do not currently have a clo value for Alpha, but will try to get that info for you.
This test is completely meaningless without context. I don't understand why you state clearly in the video that the Alpha allows a more open weave in the fabrics, but then attribute the air permeability test to the insulation. They would need the same face and liner fabrics to make that comparison. Then you don't explain how that effects insulating value, water absorbtion, compressability, or any of the other factors that actually make a big difference in choosing one insulation over another. By using a more permeable face fabric aren't they also allowing the introduction of more moisture to the Alpha insulation? Does it hold less moisture? Does Alpha dry faster? Does it have a higher insulating value? Are the 2 insulations suited for a different kinds of applications? Separate question: Insulation works by trapping air, not allowing it to flow through, so wouldn't increased airflow through the fabric make it worse as an insulator?
You are more or less right. The insulation can be the same but the point is that if air flows easily your body humidity will exit and staying dry is paramount for retaining heat. Evaporation eats a huge amount of body heat. To retain the air some form of shell is needed so the layering sistem. I also found permeability test on clothing insulation is quite meaningless. Its the outer fabric that makes the difference in this video.
+Icelandichiker The problem with this video is that it doesn't address are the fabrics used on either side of the insulation (primaloft and alpha). They look like they're similar fabrics so its hard to tell. If that is the case, Alpha would make for a better mid-layer with a breathable soft/hard shell
I want to point out a big problem with your improvised test set up to visualise and compare the breathability of different garments. I know that this test don't wants to be a scientifically valid one, but the flaw in your setup is alas that big to make the comparison nearly unusable. But to keep it short: In your test setup you use just one air pump which supplies both test cylinders parallel. But fluids or gasses take the path of the lowest resistance, where only a slight difference in A (lets say just 1% better air flow) can lead to the outcome that nearly no air passes through B. In your specific set up it would just show that the Alpha Jacket* allows more air to pass through, but nothing more -- the difference can range from neglectable small to gigantic. But if you would use an isolated for every jacket or better test them one after an other on the same pump, then you could infer the breathability from the amount of bubbles passing through the water with better accuracy. *I wrote jacket, because the test doesn't compare Primaloft one against Polartec Alpha, but a whole system, each affecting the overall performance.
Primaloft and alpha , are both really breatheable, the problem cames with the outer materials and the linnig materials. Those are the points we need to look at to talk about breatheability
