Temperature change in a vacuum?

[Jake Parker]

Hello, I'm currently taking some summer classes at my college and was assigned a project to transport vaccines from one location to another (travel time ~2-5 hours.) We have to keep the vaccine within the range of 35-46 degrees Fahrenheit at all times. My group and I came up with the idea of putting 36 degree vaccines in a vacuum chamber and assuming that temperature change for the duration of the trip would not change, therefore eliminating the need for some sort of refrigeration unit. If the outside temperature is between 20-50 degrees, will the vaccine be able to maintain a temperature within the range, or are we missing a big piece of science behind a vacuum chamber? Thanks and have a great day!

 

[Bystander]

"Vacuum chamber," or thermos bottle?

 

[Nugatory]

Try it. Take the container the vaccine ships in, fill it with water at a temperature of 36 degrees, put it in your vacuum chamber, leave the chamber in a 50 degree environment for five hours, then check the temperature of your water. Repeat in a 20 degree environment (may be harder to find) to make sure that you won't go below the minimum temperature either.

You can try calculating the rate of heat transfer to see if your idea has a chance of working, but:
1) you'll need to know something about how effectively the particular vacuum chamber you have in mind holds heat, and unless that information is available from the manufacturer you'll have to do some measurements anyways.
2) no matter how much theory-based calculating you do, you're not going to trust the results until you've tried it.

 

[Jake Parker]

"Vacuum chamber," or thermos bottle?

I mean we came up with vacuum chamber but we haven't done a lot of research on it. Will one do better than the other?

 

[Nugatory]

Well, a thermos bottle incorporates a vacuum chamber, is inexpensive, and is designed for easy transportation and effective insulation. Sounds like a good start if you can find one that your vaccine container will fit into...

But you will not know for sure until you try it. There's a reason why scientists do experiments as well as calculations.

 

[russ_watters]

Just to cover the obvious that no one has said yet: a vacuum does not eliminate heat transfer. You still have conduction and radiation.

 

[phinds]

Another thing you could try if you're looking for something quick, simple, and cheap (but you'll want to experiment on it in any case, as Nugatory has already pointed out) is to use a high grade themos but put it inside one of those plastic picnic coolers with a some ice cubes (depending on how hot it is outside). I'll bet that will last for 5 hours.

 

[Bystander]

transport vaccine

"Vaccine" implies liquid phase, implies vapor pressure, implies vapor tight seal r/t rubber septa, implies storage in "vacuum" is going to be difficult? Picnic plus thermos, yes.