ALPHA DIRECT IS NOT AN OUTER LAYER!
Polartec Alpha was designed as a batting insulation, meant to be sewn between an inner and outer shell. The Alpha insulation provided loft and dead air space. The shells provided the structure and capped the air movement. Polartec Alpha Direct was later designed, again as batting insulation, but this time to be sewn to an outer shell. The Alpha Direct provides the inner surface along with the loft and dead air space while the outer shell provides the structure and caps the air movement. Since AD is designed this way, it has it’s own structure and against the skin durability. This led to the cottage industry building stand alone garments out of it, which is a good thing because it can now be used as part of a modular system. AD has one of the the highest warmth for the weight ratios when compared to other fleece products when capped with a shell. Without a shell it has almost no insulation value at all (unless the air is perfectly still and the user is perfectly still). This means that the wearer can pick a shell appropriate for the conditions, and then ventilate it accordingly. Since it has so little insulation when directly exposed, this eliminates the need for a second set of zippers on the inner layer. As long as the outer shell has adequate ventilation and/or breathability there is none needed on the inside, which further reduces overall weight. We can go from having a very respectable amount of active insulation with a shell fully closed up over an AD insulation layer, to being able to completely dump a ton of heat out when the shell is opened up to vent. This covers a really wide range of conditions when you consider that you can mix and match the outer shell to provide rain protection, wind protection, and/or different levels of breathability. If you are in pouring rain you can cap it with an impermeable rain layer but still be able to ventilate it. If you are in high winds you can cap it with a 40cfm wind layer to stay warm but breathe just enough. If you are going for a run, you can cap it with a 90cfm layer that breathes enough to stay comfortable when your body is pumping out heat.
Alpha Direct is really an impressive product. However, it is not a do-all wonder fabric. It has limitations and hype will often take products beyond their usable range. One thing it does very poorly is function on it’s own, as an outer layer. First, it does not have enough durability to hold up this way. It’s ok to use it this way on occasion when you need to dump all your heat, but the mesh backing that holds the fibers will easily snag on things and break/rip. It rips VERY easily like this so the wearer needs to be very careful. Second, as mentioned previously, AD has almost no insulation by itself unless the air is perfectly still and the user is perfectly still. This is not a realistic scenario for an active layer. It NEEDS a shell to function. The tufts of fiber and the spaces between are the reason that it can be so warm for so little weight when capped, but it needs that cap to hold the air in those pockets. If there is no cap, then those open spaces do not hold the air hardly at all, even in no wind. A wind of 1mph will cut right through and chill you to the bone.
This is why you will see the Timmermade Alpha Direct offerings limited to basic insulation layers. Zippers create redundancy in ventilation (unless someone wants one for convenience reasons) and pockets create redundancy since they would be covered up in almost all scenarios while using an AD garment properly. There is sometimes a use case of wanting an inner pocket to hold items underneath a shell, but this happens to be another thing AD does very poorly. It has a very light and stretchy structure, which will not hold weight well. Even the weight of a phone will stretch and deform it’s structure, not to mention bounce around quite a bit.
It’s really great that innovators in the cottage industry are thinking outside the box and pushing products beyond their original design. Good designs inevitably find other uses. However, if we are going to do this, we need to think about our designs. Alpha Direct is a very unique product that should be thought of and built differently than other products.