how do vacuum flasks keep hot liquids hot and cold ones cold?

Monday, Jun,27th 2022

You can think of a vacuum flask as a water bottle holding another bottle inside it but is separated by vacuum, with a supporting stand at the bottom. This basic structure provides thermal insulation or reduction of heat transfer. A vacuum sleeve keeps liquids hot by stopping the escape of heat through three layers of protection (inner, vacuum, outer) and keeps liquids cold by not letting heat from outside enter the container, this achieved via double wall stainless steel.

Come to think about it, that’s one less thing you have to worry about.


Vacuum is a space devoid of air or any matter in its simplest sense, and Vacuum insulation has been in vogue ever since it was discovered. Let us break this scientific enigma for you for better understanding of how it works in water bottles.

Heat travels in different ways and the medium through which it does so is air or matter.

Since vacuum has either complete absence or negligible amount of matter or air, heat has a difficult time being a wanderer. You can think of Vacuum as a socially awkward person who doesn’t like to entertain the company of Heat who is highly social. Coming to vacuum insulated water bottles, from the house of Cheeki, the vacuum between the outer and inner container of the water bottles helps in maximum temperature retention, barring entry and exit of heat and you can quench your thirst with whatever temperature of water you’d like to sip in.


It isn’t exaggeration when one says that vacuum sealed bottles are the superheroes of the bottle kingdom. Like all vacuum insulated water bottles, our glass water bottle and stainless-steel insulated bottles is, yes you guessed it right, vacuum! The only difference that we see is of the body which can be made of glass or stainless steel and the inner lining. All the ways of heat transfer are cut off till the maximum amount of time by the basic mechanism of vacuum and the stopper or cap of the bottle along with the bottom stand of the water bottle. Using vacuum sealed water bottles, whether made of glass or stainless steel helps you keep your water hot and thus saving time of re-heating and saves energy, yours and the planet’s. Likewise, it keeps your water cool, rejuvenating you when you gulp it down.

Ailin galaxy Stainless steel bottles are BPA & Toxin Free. Bottle Your Own and help keep plastic bottles out of the landfill by filtering your tap water and putting it in your own bottle. It's cheaper for you and better for the planet.