Oregon Hikers

You've probably seen the Columbia line of Omni-Heat garments with the distinctive silver dots on the inside (and typically spilling to the outside of the garment, to signal to everybody else that you're wearing Columbia Omni-Heat).

I'm extremely skeptical.

As we know, heat transfer occurs in three ways:
Conduction, convection, and radiation.
The silver dots are intended to "reflect body heat to retain warmth". Can radiant heat be reflected from a shiny surface? I believe so. For example, I believe the emission from an IR heat lamp can be effectively reflected from a shiny metallic surface. So why am I skeptical about Omni-Heat? Two reasons:

#1: The claim is that my body emits radiant heat which penetrates my base layer and gets reflected off the silver dots. That doesn't sound right to me. I'm no physicist, but I would think my parka gets warm (thus stealing my heat) via conduction, perhaps aided by a little convection.

#2: Columbia Sportswear.

Thoughts?

Chip,

I have two pair of gloves, one hat and a jacket that have the Omni-Heat treatment. I can't tell if the gloves work any better, surely no worse than without. When wet, as bad as any other wet gloves. The jacket, however, seems a little better due to Omni-Heat, but then, there's no sure way to compare it unless I had the same exact jacket but without the treatment. My judgment: Neutral to maybe helps a little. If there's a actual test out there, I'd like to see the data. Maybe a jacket made with and without the Omni-Heat split right down the middle. That would make a good test. Same as for gloves - one with and one without.

dn

ps, the hat slips up over my ears and even falls off maybe due to the little reflective dots being a little slippery so I don't use it any more.

I share your skepticism

IR does not penetrate clothing. In order for an IR reflector to work there has to be an air space next to it.

It works in a Neo-air mattress because there's a reflective layer with air next to it.

It works as a space blanket if it's the outer layer, then there's an air space outside of it

But if it's well made and has good materials otherwise it could be good

Just put on my Omniheat base layer long sleeve shirt that I had not used this year. Sitting in house before hike and now remembering why I don’t wear this too often. Sometimes it gets me too warm. I will try it today and report back results.

My review after short trip around Wahkeena-Multnomah loop. The long sleeve omni-heat shirt was too warm. Had to take off my top layer and was down to just the omni-heat shirt until a bit on the ridge where the wind was blowing. I now know why I don't use this shirt very often. I should carry it as an emergency layer. Do I get a Columbia credit for this review?

I can confirm that my Columbia Omni-Heat base-layer long sleeve is the warmest shirt I own. I only wear it in the winter, usually when there's gonna be snow involved. How much of that is the dots, and how much is the shirt itself, is anyone's guess.

Chip Down wrote: ↑

February 5th, 2021, 9:15 pm

You've probably seen the Columbia line of Omni-Heat garments with the distinctive silver dots on the inside (and typically spilling to the outside of the garment, to signal to everybody else that you're wearing Columbia Omni-Heat).

As warm as it is, this is the real reason I wear it

I have a 10 year old omni-heat thin stretchy zippered "jacket" with silver dots fused to the inside surface. I use it occasionally and it's still in good shape. I use it like an inner layer on really cold days. I often wonder how well the dots work as advertised. The engineer in me tells me I will always wonder because I don't have comparison test data of a lined jacket vs an identical non-lined jacket. I doubt Columbia would ever share their testing data so we'll never know for sure. We will forever be uninformed skeptics until Columbia shares the testing data. You can read a Columbia technology discussion here. No mention is made how well it works. They seem to suggest that since it's good enough for NASA, it should work for jackets too. It's a weak argument in my opinion.

My instinct tells me that any sort of fused lining is more insulative than nothing so the dots probably help with insulation. But it's plausible that the dots could also conduct heat away, unlikely due to the Columbia reputation but still possible.

The best I can say is that my dot lined shirt doesn't make me feel colder when I wear it. I personally believe the silver dots are more of a marketing differentiation feature than a new (now old) great thing. It's something we're willing to pay for if we're convinced it works. For comparison, I have a 7 year old Columbia outer jacket with what Columbia describes as their cheaper proprietary alternative to Gore-tex. The Columbia waterproofing product never worked for me. It just slowed the internal wetting process. That experience makes me doubt Columbia's marketing claims.

It's hard to tell what the pictures in @johnspeth's link are really showing, but it looks like maybe there are little tufts of fur/fibers scattered amongst the dots that might hold the reflective dots away from the wearer by a few millimeters, which might serve to maintain something of an air gap and maybe provide some warmth. Whether it's better than a tiny bit more insulation of similar weight and probably greater durability is unknown. I'm skeptical.