How does a thin walled metal travel coffee mug not transfer the heat of the coffee to the outer surface of the cup?


My wife recently got me a new travel coffee mug and it’s the best one I have ever had as far as keeping the coffee really really hot for a long time. It is very thin walled and I just don’t understand how the heat does not transfer to the outside surface of the cup.

In: 24

Are you sure it is not double walled?

Usually it’s two layers with air or some other insulation between them. If you don’t immediately feel the heat of your coffee on the outside of the vessel, that’s probably true for this thermos, too.

Because there’s a vacuum between the inner and out walls of the mug. Vacuums are really good insulation because heat has a hard time transferring through nothing.

If the wall is just metal, then the heat will be transferred as metal conducts heat very well. If this isn’t happening, there must be a layer of something that isn’t metal in there. Most companies love to advertise their tech for doing stuff, you can probably find out more if you look up the product you have.

It’s probably a thin double walled vacuum sealed up. This makes it really hard to transfer heat from the inside shell to the outside shell.