In this dynamic world today, having a thermos is indispensable when it comes to transporting drinks, whether hot or cold, or because we want to enjoy a coffee in the middle of the work day, or to keep ourselves hydrated during physical training or to make sure our children drink milk or homemade juices while at school. If you are thinking of buying a thermos, I recommend you to check this guide to buy the best thermos among the many options offered.
How to isolate the temperature is the main feature that you should consider when buying a thermos as the thermal insulation is the essence of the creation of these containers. Liquids are heated/cooled because the heat moves from the hot to the cold, and the temperature can be lost by convection, conduction or radiation, which are the forms of transfers that the thermos try to avoid in their manufacture.
It is formed by a vessel inside another with an empty space between them because, by convection, the vacuum prevents the passage of heat towards the vessel, avoiding to heat a cold liquid or preventing a hot liquid from cooling.
In manufacturing, materials with little or no heat transfer, such as glass, are often used to prevent transmission by conduction, although the glass has ceased to be used as an insulation material because of the brittleness of this material. Likewise, they have a mirror finish internally to make the heat rebound and return, either in or out of them, avoiding radiation transmission.
In theory, a thermos should maintain the temperature of the liquid perennially, but in practice the content is cooled/heated because heat passes through the mouth of the vessel, so the cover is the second important feature that you should have in mind when comparing how much a thermos costs. The lid is the element that complements the thermal insulation, so it usually has a tight rubber seal to prevent heat transfer.
The capacity of a thermos can be specified based on 2 parameters, the amount of liquid it can hold inside it and the time in which it can maintain its temperature.
When comparing, you will find that the amount of liquid supported can vary between 250 ml and 500 ml. The temperature holding time can also vary from 1 to 4 hours for hot liquids and from 4 to 12 hours for cold liquids. The ability to maintain the proper temperature is directly affected by the processing material and the sealing technology, so it is advisable to check these specifications to find which thermos is best.