Does anyone know how long hot water stays hot in a thermos

[optimistic]

It's your average thermos. Stainless steel, with plastic interior lining and what I'm guessing foam isulation. I've never brought a thermos to work and I assume when others do -its only for their morning commute.

How likely is the water in the thermos to stay warm after 7hrs? Like if packed at 5am, will it still be hot at 12 noon?

 

[Cooljt1]

i dont know exact temperatures or anything but it should still be pretty warm even after seven hours. also it depends on what the temperature outside the thermos is.

 

[0roo0roo]

pretty warm yea.. but true thermos have a vacumn between two layers of material. heat doesn't travel through a vacumn all that well.. far better then foam lined bs.

 

[Whitecloak]

Originally posted by: 0roo0roo
heat doesn't travel through a vacumn all that well..

ever hear of radiation?

 

if it's a good thermos, it'll still be hot
when i used to hunt, i'd pour a pot of coffee in at 4, at 11am it'd still be hot enough to hurt like a mofo when you try to pour yourself a cup while driving and end up spilling all over your crotch

 

[Ameesh]

Originally posted by: whitecloak

Originally posted by: 0roo0roo
heat doesn't travel through a vacumn all that well..

ever hear of radiation?

it depends on what kind of radiation you are talking about tough guy, r00r00 is correct, the vacuum helps keep the liquids from transfering heat to the outer chamber

 

[Whitecloak]

Originally posted by: Ameesh

Originally posted by: whitecloak

Originally posted by: 0roo0roo
heat doesn't travel through a vacumn all that well..

ever hear of radiation?

it depends on what kind of radiation you are talking about tough guy, r00r00 is correct, the vacuum helps keep the liquids from transfering heat to the outer chamber

the vacuum prevents heat transfer through conduction. Radiative heat transfer still occurs.

 

you guys drink radioactive coffee?

 

[Colt45]

only shitass thermos' have no vacuum canister deal.

 

[rgwalt]

Originally posted by: whitecloak

Originally posted by: 0roo0roo
heat doesn't travel through a vacumn all that well..

ever hear of radiation?

The amount of heat transferred through a vacuum via radiation, in the case of a thermos bottle, is miniscule. I have a really nice thermos that keeps my coffee HOT for 8+ hours. It is awesome. A thermos will also keep cold liquids cold, so you can carry your iced tea with you in the summer.

R

 

[AIWGuru]

This vacuum would have some pretty limited usefullness. The inner chamber would have to be connected to the outter chamber at some point. It can't float magically inside.
That means that at the connection point (probably at the mouth and bottom) conduction will still occur.

 

[Howard]

Originally posted by: AIWGuru
This vacuum would have some pretty limited usefullness. The inner chamber would have to be connected to the outter chamber at some point. It can't float magically inside.
That means that at the connection point (probably at the mouth and bottom) conduction will still occur.

But those spots need not lose heat quickly... Cork doesn't conduct that well, and if you REALLY want to maintain your liquids at temp, you can use a layer of aerogel between the vessel and the supporting points.

 

[StageLeft]

This vacuum would have some pretty limited usefullness. The inner chamber would have to be connected to the outter chamber at some point. It can't float magically inside.
That means that at the connection point (probably at the mouth and bottom) conduction will still occur.

But, if the contact point is minimal the vacuums still serve a purpose. Indeed, the good thermos' do have vaccums. I got a Nissan brand one (I don't think it's the car manufacturer) for around 500 ml and it does a great job. The same company has a larger flask that supposedly can keep coffee hot after -24 hours-. It's got graphs of temperature drop and if you put in nearly boiling-hot coffee you can have a nice warm cup fully 24 hours later.

 

[rgwalt]

Originally posted by: AIWGuru
This vacuum would have some pretty limited usefullness. The inner chamber would have to be connected to the outter chamber at some point. It can't float magically inside.
That means that at the connection point (probably at the mouth and bottom) conduction will still occur.

The fact remains that thermos bottles do have a vacuum gap between the inner chamber and the outer skin. The vacuum gap insulates the thermos from heat loss as the contact point is extremely small. Furthermore, a good thermos bottle will keep coffee hot for 6 or 8 hours.

R