HOW TUMBLERS WORK TO KEEP COFFEE HOT AND ICE WATER COLD
It’s been said that a good magician never shares the secrets to their magic tricks, and although insulated tumblers may seem to work like magic, it's no trick. Greens Steel insulated tumblers retain the temperature of hot drinks for six hours and cold drinks for 12 hours not by pulling rabbits out of a hat, but with science - and pretty simple science at that.
This quick guide explains all you need to know about the different types of insulated cups, their structure, what double wall vacuum insulation means, and of course, how insulated cups, water bottles, and coffee tumblers work.
Now pick a card, any card... just kidding.
Topics Covered in This Guide
STRUCTURE OF DOUBLE WALL VACUUM INSULATED TUMBLERS
There are four different ways tumblers, water bottles, and cups can be insulated; air insulation, foam insulation, vacuum insulation, and copper insulation.
When it comes to stainless steel drinkware, double wall vacuum insulation is the best option.
If you were to see a stainless steel double wall vacuum insulated tumbler down the middle from top to bottom, you would see two layers of steel connected at the top separated by an empty space.
To understand the structure better, let's break down what "double wall" and "vacuum insulation" means.
HEAT TRANSFER EXPLAINED
Now before we move on to how insulated tumblers work, let's quickly review the three ways that heat transfers - conduction, convection, and radiation.
Heat conduction takes place when two objects or liquids are touching. The heat from the object of higher temperature is transferred to the object of lower temperature. For example, the heat from coffee is transferred into the human body through conduction.
Greens' Tips: Some objects and liquids have better thermal conductivity than others and have better heat conduction properties.
Convection occurs when fluids (liquids or gases) are heated or cooled from being exposed to an external source and move from one location to another. Colder fluids replace the space that the heated fluids left, and the cycle continues.
An everyday example of convection is boiling water in a kettle; the heat from the stovetop is transferred to the bottom layer of water. This layer of hot water then rises to the top and the colder top layer of water moves down to replace it.
Greens' Tips: Fluids do not need to be touching for convection to occur.
Radiation heat transfer happens when the surface of hot things emit heat waves, which are in turn transmitted, absorbed, or reflected by a colder object, surface, or liquid. You experience heat radiation everyday when heat radiating from the sun touches your skin.
HOW INSULATED TUMBLERS WORK
Now that we understand the structure of insulated tumblers and how heat is transferred, it's time to put all the pieces together to answer, "How do insulated tumblers work?"
HOW INSULATED TUMBLERS KEEP DRINKS HOT
After a tumbler is filled up with a hot drink and the lid is sealed tightly, all three methods of heat transfer to and from the drink are eliminated.
The loss of heat through conduction is eliminated via the double walled structure separated by the vacuum layer seeing as no external object can touch the liquid or the layer of wall touching the hot drink.
Heat convection is also prevented by the double wall vacuum layer because no external air can come into contact with the hot liquids from the sides. The airtight lid also prevents hot air escaping and convection from cooler currents from coming in.
Greens' Tips: If colder currents were to come in, it would cool the top layer of liquid, which would then be replaced by the hotter layer beneath it. This process would repeat until the contents lose all of its heat.
HOW INSULATED TUMBLERS WORKS ON A COLD DRINK
When a cold drink is added to a double-wall vacuum insulated stainless steel tumbler, the same process happens in reverse; instead of preventing heat transferred from hot liquids, it prevents external heat being transferred into cold liquids.
External heat transferred via conduction is prevented by the double wall vacuum insulation seeing as no external object can transfer heat into the cold drink. Transfer of external heat via convection is prevented by the lid and vacuum sealed construction because no external heated air can transfer energy into the cold beverages.
Finally, external heat transfer through radiation is eliminated from the lid and stainless steel exterior reflecting external heat radiation away from the cold contents.
WHAT IS THE BEST INSULATED TUMBLER?
With over 60,000 reviews on the website and Amazon pages, the Greens Steel BEAST Tumbler is without a doubt the best stainless steel tumbler. Made from dishwasher safe 18/8 food grade stainless steel, this unbeatable tumbler features double wall vacuum insulation with copper lining and comes with a lifetime warranty, easy clean Tritan BPA free splash proof lid, two reusable stainless steel straws, and a easy to use brush cleaner all packaged in an eco-friendly gift box.
DOUBLE INSULATED COFFEE TUMBLER WITH STRAWS AND LID
Keeps your hot coffee steaming and cold drinks ice cold
Available in 20oz, 30oz, 40oz and a variety of color optionsShop Now
I love science; it can be understood by anyone and replicated endlessly, where magic tricks are complicated illusions that lose their glamour once the secret is revealed. Somebody call Copperfield and tell him the BEAST is taking up his Vegas residency.
For more interesting behind the scenes stories about stainless steel insulated water bottles, coffee tumblers, and cups, check out our top picks from the Greens Steel blog below.