Nano Puff vs Atom LT: Things to Consider [Nov '19]

As some of you know, I just recently compared Arc'teryx's Atom LT to Proton LT and also compared Patagonia's Nano Puff to Micro Puff.

Now I wanted to make a post about Nano Puff vs Atom LT because assuming no wind, rain, or snow and little to no activity, they offer about the same warmth. So some of you could be having a dilemma between these two.

Unlike Atom LT, Nano Puff does come with a stuff sack.

Overview

The advantages Nano Puff has over Atom LT is that it:

Is more weather resistant,
Comes with and stuffs into its own sack (Atom LT doesn't come with one),
Is slightly lighter {363 grams (12.8 ounces) vs 415 grams (14.6 ounces)}

Now you understand why Nano Puff is a really popular jacket around traveler folks, and also why it's one of my top synthetic insulated jacket for travelers.

Atom LT, on the other hand,

Is much more breathable (because of its famous side fleece panels),
Is more comfortable,
And looks better (at least to me - especially this Orion color with Flux interior).

Atom LT is much more suitable than the Nano Puff for high output activities.

So, in summary, if you'll be using the jacket both in the town & during high output activities, then your jacket is probably Atom LT (if, for some reason, Proton LT isn't an option for you). If you'll mostly be traveling with the jacket and won't be physically active with it, then Nano Puff would probably be a better choice.

Lastly, do not get either of these jackets if you'll be out in below 30 deg F (0 deg C) a fair amount of days - because you'll quite likely to feel chilly inside them (assuming no substantial under layering - just a long sleeved shirt) unless you run much warmer than the average person.

Different insulation materials

Atom LT's Coreloft is made with highly crimped multi-denier siliconized polyester yarn.

Lowest temperatures you can wear these jackets without feeling uncomfortably cold are...

	°F / °C	Insulation
Ceres SV (Men's)	-15/-26	Down	Read Review
Firebee AR (Men's - Women's)	-10/-23	Down	Read Review
Dually Belay (Men's)	-7/-22	Synthetic
Thorsen (Men's)	-7/-22	Down	Read Review
Centrale (Women's)	-5/-20	Down	Read Review
Cerium SV (Men's - Women's)	-5/-20	Down	Read Review
Therme (Men's)	-2/-18	Down	Read Review
Camosun (Men's)	0/-17	Down	Read Review
Patera (Women's)	5/-15	Down	Read Review
Thorium AR (Men's - Women's)	8/-13	Down	Read Review
Kappa (Men's)	10/-12	Synthetic
Atom AR (Men's - Women's)	10/-12	Synthetic	Read Review
Magnus (Men's)	14/-10	Down
Cerium LT (Men's - Women's)	17/-8	Down	Read Review
Atom LT (Men's - Women's)	23/-5	Synthetic	Read Review
Proton LT (Men's - Women's)	23/-5	Synthetic	Read Review
Cerium SL (Men's - Women's)	40/5	Down	Read Review
Atom SL (Men's - Women's)	50/10	Synthetic	Read Review

Here's the full chart.

These are only approximate values assuming:

you only have a long sleeved shirt under and no shell over,
during daily use (strolls, power walks etc at most - no high output activities),
with enough wind to cause an umbrella to twist in your hand,
and when it's dry out.

Also check out my Arc'teryx Favorites.

If you think you run warmer or colder than the average person, then shift temperature ranges accordingly.

Its lightweight, breathable and thermally efficient 100% polyester staple fibre is compressible and has good loft retention. Comes in the following six weights:

1.2 oz/yd2, 40 g/m2,
1.8 oz/yd2, 60 g/m2 (the density Atom LT uses),
2.4 oz/yd2, 80 g/m2,
3.0 oz/yd2, 100 g/m2,
3.5 oz/yd2, 120 g/m2,
4.2 oz/yd2, 140 g/m2.

Nano Puff's 60 grams of Primaloft Gold Insulation Eco

So how do these different insulation techniques play out when using these jackets?

Breathability

Atom LT's 60 g/m2 is the higher breathability / less warmth region for Arc'teryx's jackets. 60 g/m2 also compromises weather resistance to achieve more stretch and comfort.

Jackets like the Atom AR [Read Review], for example, use

120 g/m2 Coreloft - which in the end provides significantly more warmth but also significantly less breathability.

Eventually it all comes down to your personal preferences as to the strong aspects of a jacket.

The main advantage you'll have with the Nano Puff's 60 grams of Primaloft Gold Insulation Eco over Atom LT's 60 g/m2 Coreloft, on the other hand, is that it's more compressible (which is why it comes with a stuff sack) and provides superior wet-weather performance.

But insulator difference isn't the main thing that makes Atom LT more breathable than the Nano Puff.

Atom LT's side fleece panels

The game-changer here is actually Atom LT's side fleece panels.

If you're having a dilemma between these two jackets, then you should have heard of these panels before already - they're admired by many users.

First I want to say that using fleece panels with the intention to make a jacket more breathable is considered outdated in today's outdoor gear world.

The reason is that there has been a lot of advanced breathable insulators released into the market. Jackets made with genuinely breathable materials such as Arcteryx's Proton LT and Patagonia's Nano Air started to take the lead.

But there are many climbers and skiers still using jackets with side fleece panels today. My, too, first choice would be Proton LT as you can see hereh when it comes to choosing a jacket for a combination of casual and active use - but Atom LT is a good alternative.

Needless to say, Nano Puff doesn't offer side fleece panels.

Nano Puff can be better than the Atom LT for very low to none activity level.

Warmth

I'd say, generally speaking, when it's dry out, with only a long sleeved shirt under and without a shell on top, with a mild wind and very low to no activity level...

The approximate lowest temperatures an average person can wear these jackets without feeling cold would be around 30 deg F (0 deg C).

Like I said earlier, they provide about the same warmth as you see. If you think you run hotter or colder than the average person, then shift this temperature {30 deg F (0 deg C)} accordingly.

When there's anything more than a light rain, though, Atom LT's performance will drop slightly below Nano Puff's.

Which brings me to my next point...

Different face fabrics

This factor will play out in durability, comfort and weather resistance.

Although side fleece panels of LT make it much more breathable, it inevitably compromises wind resistance in return significantly. Wind will cut right through it.

You can solve this by under layering an Atom LT with a wind-shirt. But that requires extra effort from the buyer's side, so I'd write minus points for Atom LT in this department.

The fabric of Nano Puff (Shell: 1.4-oz 20D 100% recycled polyester, Lining: 1.3-oz 22D 100% recycled polyester) isn't any better than that of Atom LT (Tyono 20D / Polartec Power Stretch), but it isn't equipped with side fleece panels, it certainly isn't THAT vulnerable against strong winds.

Both are DWR coated.

What's DWR by the way?

DWR is a coating. It's basically sprayed on to the surface of these jackets as a finish. It stands for Durable Water Repellent - which means that water will be repelled under wet conditions instead of soaking into the fabric. DWR also decreases dry time.

It's a good thing these jackets are coated in DWR, but pay attention to the fact that DWR is a coating - meaning that it will wear off over time.

Which is why you might want to invest in a DWR spray such as this one for after treatment.

Gentle, smooth, stretchy inner surface of Atom LT provides much more comfort than Nano Puff. This is especially important when you're active with the jacket.

Slightly more robust outer shell of Nano Puff is slightly more durable than Atom LT's stretching fabrics which is intended to increase comfort during high output activities.

But still, the Nano Puff won't be able to counter an abrasion caused by a stiff or pointy rock when climbing either, just like Atom LT. I wouldn't say they're much different than one another when it comes to durability.