The 3 fundamental types of MiiR insulation.
Single Wall: This isn’t really “insulation”. Heat is transferred quickly through the stainless steel via conduction. That’s why these cups will sweat when they contain cold liquids and burn you when they contain hot liquids!
Double wall Insulation: Just like it sounds, it’s two stainless steel walls separated by air. This wall of air insulates the cup by forcing heat to transfer through a layer of air. This means the heat has to transfer first by conduction through one layer of steel, then by radiation and convection through the vacuum, and lastly by conduction through the other layer of steel.
Vacuum Insulation: This is the most efficient form of insulation for stainless steel vessels. In reality, it’s impossible to create a perfect vacuum between the walls. But by removing as much of the air as possible, convection becomes ineffective. The heat can only radiate between the steel walls. Fewer methods of heat transfer means better insulation.
The 3 fundamental types of heat transfer:
Conduction – This is energy transfer between objects that are touching. Think of your hand on a metal table vs a wood one. The metal one feels cooler than the wood one because it has better thermal conductivity, so it’s conducting heat from your hand more quickly.
Convection – This is energy transfer from an object and its environment through fluid movement. Think of a nice breeze when you are hot. The wind cools you down because it moves your body’s heat away from you.
Radiation – This is the transfer of energy via electromagnetic radiation or light. Visible light, the stuff that your eyes see, is a form of electromagnetic radiation. Everything around you is always emitting thermal radiation. Think of an incandescent light bulb. They work by simply heating a filament up so hot that some of the electromagnetic radiation it gives off is visible light. Most of the energy is different wavelengths so we perceive it as heat. That’s why old fashioned incandescent bulbs are inefficient and get so hot!