The Yeti tumblers & coolers are truly amazing!! And they’re tough. Worth every penny. 

Want to see what’s inside a Yeti Cup? Watch this father & son do some fun experimenting!!! :)))

Being a heat treating guy, I always look closely at things that are hot, and things that are cold.  The other day, driving to work, I picked up my “insulated” coffee mug, and thought, “I wonder why this works so well.” Insulated tumblers, and coolers, like the successful Yeti brand, work really well to keep beverages cool or hot for very long periods of time (talk about PIA (Pain in the @%$) Jobs!).  I have memories of being down on the lakefront at a Brown’s game, reaching for my thermos, and pouring out hot, creamy tomato soup, watching the steam rise.  Of course, it was 13 degrees, with a wind chill of minus 72. Sipping the warm soup was ecstasy, as I watched my Brownies bungle another game.  So, I searched the internet and found some great info on the Yeti tumbler and got in depth info on exactly how these things work to keep heat out or to keep temperature in.  Enjoy, and thanks to,,, and You Tube for the insights.

In a Yeti tumbler, while it just looks like a metal cup, it’s actually got an inner wall and it has an outer wall.  They are made of vacuum sealed stainless steel. The vacuum is what keeps out the majority of the heat by stopping heat conduction and convection. We here at KHT know a thing or two or three about vacuums!  The inside also has a copper plating to insulate against heat radiation as stainless steel itself is a poor conductor of heat. All of these elements combined with a plastic lid (another insulator) allow the tumblers to keep beverages cold or hot for so long.

In a “good” tumbler, there’s actually a gap in between the two walls and in between that gap is a vacuum. So, in manufacturing, they suck all of the air out of there so there’s basically nothing in there (or as close to nothing as they can get).

There’s different ways that heat is transferred from the outside air to the inside of your tumbler.

1. Conduction – you’ve got conduction which is the movement of heat from one object touching another. That’s the external heat from the air moving through the metal of the cup and into the contents inside your cup.

2. Convection – you’ve got convection, where air or water currents can move heat around.

3. Radiation – then you’ve got radiation which is heat that can pass through a vacuum.

Yeti tumblers are designed to effectively stop all 3 types of heat transfer, or minimize them as much as possible.

Now, let’s get serious on the “science” side:  Conduction needs particles for heat to move through and because there’s a vacuum and because there’s nothingness in between the two walls of the tumbler there’s actually no way for heat to pass through in conduction.  The only way for heat to do that is to actually hit the cup and actually pass through at the top of the cup where the inner wall and the outer wall is connected, as at the bottom of the cup the outer wall and inner wall aren’t actually connected. (got it?)

The only connecting point is the top of the cup and heat would need to move from the exterior of the cup all the way up to the top and all the way in – and that just doesn’t really happen.

Because thermos containers are made out of stainless steel (stainless steel is a terrible conductor of heat), the “lack of air” acts as an insulating material. This means the heat is unlikely to move from the outside up and around reducing conduction.

Convection is the movement of particles. For example, if you make a really hot pocket of water in the bath by turning the tap on hot and you “push” the hot water around that’s convection. (when I make a bath for the grandkids, I make sure to “blend” the water before they jump in).

When you have a vacuum present, there’s nothing to push around. So convection doesn’t happen in Yeti brand, or other tumblers, for this very reason.

The last tip of info is radiation. The sun’s rays obviously travel through space (which is a vacuum) and then heat up the earth. Radiation is always happening and will be able to go through the vacuum. (So even though the cup has a vacuum, this doesn’t protect it against radiation).

To protect against heat radiation, the interior is actually copper plated. Copper is a great reflector of radiation and so having that copper lining reflects the radiation trying to get in.  Learn more about shielding

The lid hole is the only space heat/cold can escape.  The newer tumblers have a magnetic slide so you can close it shut when you’re not drinking out of it.

The full cup is acting as an insulator, the top and the plastic is acting as a bit of an insulator as well and that’s what allows these to work so well and to keep ice for so long.

Now that you know how the thermal management of conduction, convection and radiation – watch this video comparing a $400 Yeti cooler to a $50 standard cooler – (you might be surprised!!).

So, next time at the beach, or camping, or just driving to work, you know!


Me, too.

As you may know the Kowalski Heat Treating logo finds its way
into the visuals of my Friday posts.
I.  Love.  My.  Logo.
One week there could be three logos.
The next week there could be 15 logos.
And sometimes the logo is very small or just a partial logo showing.
But there are always logos in some of the pictures.
So, I challenge you, my beloved readers, to count them and send me a
quick email with the total number of logos in the Friday post.
On the following Tuesday I’ll pick a winner from the correct answers
and send that lucky person some great KHT swag.
So, start counting and good luck!  
Oh, and the logos at the very top header don’t count.
Got it? Good.  :-))))
Have fun!!