Under Armour is a manufacturer of sports/active clothing. Their HeatGear claims to keep you cool and dry in the heat. Their ColdGear claims to keep you warm and dry in the cold. One of the technologies offered within their ColdGear line is “Infrared”. This is from their website:
STAY WARMER LONGER.
WHAT’S IT DO?
ColdGear® Infrared doesn’t just make you warm, it keeps you warm…with no extra weight or bulk.
HOW’S IT WORK?
Soft, thermo-conductive coating inside absorbs and retains your own body heat.
WHY’S IT BETTER?
Infrared imaging detects and pinpoints heat loss in insulation systems.
From their description, I can’t reconcile what method of heat transfer they’re trying to minimize. For example:
Conduction: Placing a medium with a low thermal conductivity, ie. insulation that creates pockets of (mostly) air, between the body and the environment.
Convection: Using zippers, cinches, wind resistant fabrics to minimize mixing of your warm air with the cold ambient air.
Radiation: Using a reflective surface to reflect and return heat that would normally be lost to the environment, ie. Mylar/“Space” blanket.
The Infrared technology seems conflicting.
A coating that “absorbs and retains” heat suggests an energy reserve. The effects would be negligible unless the coating has a high specific heat and/or mass. Besides, you would feel cold when initially putting on the jacket, since it’s absorbing heat.
“Conductive” is not a word usually reserved for effective insulation.
The clothing line is well reviewed when reading online blogs and retailers’ websites, but it’s hard to say if kickbacks and/or placebo effects are in play.
So, Under Armour ColdGear Infrared clothing line; effective technology or effective marketing?